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FOOD INSPECTION AND ANALYSIS. 



FO/? THE t/5£ OF PUBLIC ANALYSTS, HEALTH ^ 
OFFICERS, SANITARY CHEMISTS, 
AND FOOD ECONOMISTS. 



"^^ 



ALBERT E. l^EACH. S.B., 

Analyst of the Massachusetts State Board of Health, 




7 



FIRST E D I T T O N . 

FIRST THOUSAND. 



NEW YORK: 

JOHN WILEY & SONS. 
London: CHAPMAN & HALL, Limited, 

1904. 






LIBRARY of CONGRESS 

Two Copies RacMved 

AUG 22 1904 

Cooyrlrtt Entry 

GLASS "^XXo. Na 

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i COPY B [ 



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Copyright, 1904, 

BY 

ALBERT E. LEACH. 



rOBERT DRUMMONO, PRINTER, NEW YO!^K. 



Affectionately Dedicated to the Memory of 
CljarlfS IDoiufcov UL'orcrgtrr, 

former Analyst of the Massachusetts State Board of Health, 

whose lovable personality and sterling integrity were 

a constant inspiration during many years 

of close companionship to 

THE AUTHOR. 



PREFACE. 



In the preparation of the present work, the requirements of the public 
analyst are mainly kept in view, as well as of such officials as naturally 
cooperate with him in carr}'ing out the provisions of the laws dealing 
with the suppression of food adulteration in states and municipalities. 
To this end special prominence is given to the nature and extent of adul- 
teration in the various foods, to methods of analysis for the detection of 
adulterants, and to some extent also to the machinery of inspection. 

While the analyst may not in all cases have directly to deal with the 
minutice of food inspection, his work is so closely allied therewith that 
this branch of the subject is of vital interest and importance to him. 
Indeed, in many smaller cities one official often has charge of the entire 
work, combining the duties of both inspector and analyst. 

Endeavor has been made, furthermore, to deal with the general com- 
position of foods, and to give such analytical processes as are likely to 
be needed by the sanitary chemist, or by the student who wishes to 
determine the proximate components of food materials. 

It has been thought best to include brief synopses of processes of 
manufacture or preparation of certain foods and food materials, in cases 
where impurities might be suggested incidental to their preparation. 

In view of the fact that Massachusetts was the pioneer state to adopt, 
over twenty years ago, a practical system of food and drug inspection, 
and for many years was the only state to enjoy such a system, no apology 
is perhaps needed for more frequent mention of Massachusetts methods 
and customs than those of many other states, in which the food laws 
are now being enforced with equal zeal and efficiency. 

Considerable attention has been paid in the following pages to the 
use of the microscope in food analysis. Of the figures in the text iUus- 



vi PREF/ICE. 

trating the microscopical structure of powdered tea, coffee, cocoa, and 
thie spices, fifteen liave been reproduced from the admirable drawings 
of Dr. Josef Moeller, of the University of Graz, Austria. Acknowledg- 
ment is gratefully given Dr. Moeller for his kind consent to their use. 

The photomicrographs in half-tone, forming the set of plates at the 
end of the volume, were all made in the author's laboratory, and may 
be divided into three classes: ist, illustrations of powdered pure foods 
and food products, as well as of powdered adulterants; 2d, types of 
adulterated foods, chosen from samples collected from time to time in 
the routine course of inspection; and 3d, photographs of permanently 
mounted sections of foods and adulterants. 

While recent works covering the whole field of general food analysis 
are comparatively few, the number of treatises, monographs, government 
bulletins, and articles scattered through the journals, dealing with special 
subjects relative to food and it& inspection, is surprisingly large, and from 
a painstaking review of these much information has been culled, for which 
it has been the author's intention at all times to give credit. 

Special mention should here be made of the valuable publications of 
the U. S. Department of Agriculture, both the bulletins issued from 
Washington, and those from the various experiment stations, an ever- 
increasing number of which are becoming engaged in human food 
work. The author has freely drawn from these sources, and especially 
from the data and material furnished by his coworkers in the recent 
and still pending labor of preparing food methods for the Association of 
Oflicial Agricultural Chemists, and he wishes to extend his thanks to 
all of them for their assistance. Appreciation is also expressed for the 
care and discrimination shown by Mr. L. L. Poates in the preparation of 
the cuts. Thanks are especially due to Mr. Hermann C. Lythgoe, 
Assistant Analyst of the Massachusetts State Board of Health, for his 
invaluable cooperation, and to Dr. Thomas M. Drown for helpful hints 
and suggestions. 

Boston, Mass., July i, 1904. 



TABLE OF CONTENTS. 



CHAPTER I. 

PAGE 

Food Analysis and State Conteoi i-n 

Introductory, i. Food Analysis from the Dietetic Standpoint, 2. Systematic 
Food Inspection; Functions of the State Analyst; Standards of Purity; Nature of 
Analytical Methods, ^-^. Adulteration of Food, 5. A Typical System of Food 
Inspection, 5-8. Practical Enforcement of the Food Laws; Publication; Notifi- 
cation; Prosecutiim, q. 

References on Food Inspection and State Control, 10. 



CHAPTER II. 

The Lahoratory and its Equipment 12-34 

Location, 12. Floor; Lighting; Benches, 13. Hoods, 14. Sinks and Drains, 
15. Suction and Blast, 17. Apparatus, iS-23. Reagents, 24-30. Equivalents of 
Standard Solutions; Indicators, 34. 

References on Laboratory Equipment, Reagents, etc., 34. 

CHAPTER III. 

Food, its Functions, PROxniATE Components, and Nuteith-e ^^\LUE 35-46 

Nature and General Composition of Food, 35. Fats, 35. Protein, and Classifi- 
cation of Nitrogenous Bodies, 36. Proteids, their Subdivisions, Occurrence, and 
Characteristic Tests, 36-39. Albuminoids, 30. .Amido Compounds, 40. Alka- 
loids; Nitrates; .Ammonia; Lecithin, 41. Carbohydrates and their Classification, 
41. Organic Acids; Mineral or Inorganic Materials, 42. Fuel \'alue of Food, 42. 
The Bomb Calorimeter, 43. 

References on Dietetics and Economy of Food, 44. 

CHAPTER IV. 

Gener.\l .Analytical JIethods 47-69 

Expression of Results, 47. Preparation of Sample, 48. Specific Gravity; 
Methods, and .'\pparatus, 49-54. Determination of Moisture; Determination of 
.Ash, 55. Continuous Extraction with Volatile Solvents, 57-60. Separation with 
Immiscible Solvents, 60. Determination of Nitrogen, 61-63. Determination of 
Free .Ammonia; Detennination of .Amido Nitrogen, 64. Determination of Carbo- 
hydrates, 64. Poisoned Foods, 64. Detection and Determination of .A.rsenic, 65, 66. 
References on General Food .Analysis, 67. 

vii 



viii T^BLE OF CONTENTS. 

CHAPTER V. 

PAGE 

The Microscope in Fjod Analysis 69-87 

Microscopical vs. Chemical Analysis, 69. Technique of Food Microscopy, 70. 
Apparatus and Accessories, 70-72. Preparation of Vegetable Foods for Micro- 
scopical Examination, 73. ' Microscopical Diagnosis, 74. Vegetable Tissues and 
Cell Contents, under the Microscope, 75-78. Microscopical Reagents, 78-81. 
Microchemical Reactions, 82. Photomicrography; Appurtenances and Methods, 
81-86. 

References on the Microscope in Food .Analysis, 86. 

CHAPTER VI. 

Milk and Milk Products 88-164 

Composition and Characteristics of Milk, 88. Milk Sugar; Milk Proteids, and 
other Nitrogenous Bodies, 8g. Milk Fat; Citric Acid; Composition of the Ash, 
91. Fore Milk and Strippings, 92. Colostrum; Frozen Milk; Fermentations of 
Milk, 93. Analysis of Milk, 94. Specific Gravity, 95-97. Total Sohds, 97. 
Ash, 98. Fat, by Extraction, by Centrifugal, and by Refractometric Methods, 98- 
108. Proteids; Casein, 109. Albumin, no. Other Nitrogenous Bodies, in. 
Milk Sugar, by Optical Methods, in-113, by Fehling's Solution, 113-115. Relation 
between the Various Milk Constituents; Calculation by Formulce, 115-118. Acid- 
ity, 117. Boiled Milk, 119. Modified Milk and its Preparation, 119-121. Pre- 
pared Milk Foods, Milk Powders, and Artificial Albuminous Foods, 121, 122. 
Koumis; Kephir, 122. 

Milk Adulteration and Inspection; Milk Standards, 123, 124. Forms of Adul- 
teration, and Variation in Standard, 124-126. Rapid Approximate Methods of 
Examination, 127-129. Systematic Routine Examination, 129. Analytical 
Methods for Solids, Fat, and Ash, 130-133. Added Foreign Ingredients, 133. 
Coloring Matters and their Detection, 134-137. Preservatives, their Relative 
Efficiency and their Detection, 137-145. Added Cane Sugar, 145. Added 
Starch; Added Condensed Milk, 146. Analysis of Sour Milk, 146. 

Condensed Milk; Composition, Standards, Adulteration, 146-148. Methods of 
Analysis, 148-153. Calculation of Fat in Original Milk, 152. 

Cream; Composition, Analytical Methods, Standards, Adulterants, 153-155. 
Gelatin in Cream, 155; Sucrate of Lime in Cream, 156. 

Cheese; Composition, Varieties, 157. Standards; Adulteration, 158. Analyt- 
ical Methods, 159. Separation and Determination of Nitrogenous Bodies, 160— 
162. Lactic Acid; Milk Sugar; Foreign Fat, 162. 

References on Milk and its Products, 163. 

CHAPTER VII. 

Flesh Foods 165-202 

Meat; Structure and Composition, 165. Proximate Components of the Common 
Meats, 166-170. Meat Inspection, 171. Standards, 172. Meat Preservatives, 
172. Curing, 173. Use of Antiseptics; Effect of Cooking," 174. Canned Meats, 
175, 176. Sausages, 177. Analytical Methods, 178. Fats of Meats, 179. Clas- 
sification, Separation, and Determination of Nitrogenous Bodies, 180-184. Deter- 
mination of Gelatin, 1S3. Determination of Flesh Bases, 1S4. Preservatives and 
their Detection, 184. Starch in Sausages, 185. Horseflesh in Sausages, and its 
Detection, 186-190. Muscle Sugar, 190. Coloring Matters and their Detection, 
190, 191. Detection of Frozen Meat, 191. 



TABLE OF CONTENTS. ix 

PACE 

Meat Extracts; Character and Composition, 192-194. Methods of Analysis, 
195. Separation of Nitrogenous Compounds, 195-198. 

Fish; .Structure, Composition, and Methods of Analysis, 198-199. Crustaceans 
and Mollusks, 200. Analyticaf Methods; Preservatives in Fish and Oysters, 201. 

Concentrated Foods for Armies and Campers, 201. 

References on Flesh Foods, 202. 



CHAPTER Vlir. 



Eggs 



203-211 

Nature and Composition, 203. The Egg White and its Nitrogenous Com- 
pounds, 204. Preparation of Albumin, 205. The Egg Yolk and its Composition, 
205. Composition of the Ash, 206. Analytical Methods; Determination of Leci- 
thin, 207. Preservation of Eggs, 208. Physical Methods of E.xamination, 209. 
Desiccated Egg; Egg Substitutes, 209. Custard Powders, 210. 
References on Eggs, 211. 

CHAPTER IX. 

Cereals and their Products, Legumes, Vegetables, and Fruits 212-275 

Composition of Cereals, Vegetables, Fruits, and Nuts, 212-217. Methods of 
Proximate Analysis, 217-219. Carbohydrates of Cereals, 219. Starch; Detection, 
Varieties, Classification, Microscopical E.Namination, 219-223. Starch Deter- 
mination, by Direct Acid Conversion and by Diastase Methods, 223, 224. Cellu- 
lose or Crude Fiber, 224. Pentosans and their Determination, 225, 226. Separa- 
tion and Determination of the Carbohydrates of Cereals, 227, 228. Proteids of 
Cereals and Vegetables; Separation and Methods of Analysis, 228-230. Proteids 
of Wheat, their Separation and Determination, 230, 231. Proteids of Other Cereals 
and Vegetables, 232, 233. Ash of Cereals and Vegetables, 233, 234. 

Flour; Composition; Milling; Inspection, 235. .■\dulteration, 237. .Alum, 237. 
Gluten Flour, 238. Ergot, 239. Microscopical Examination of Flour and Meal, 
239. Wheat Flour, 241. Meal of Rye, Barley, and Oats, 242. Corn Meal, 
244. 

Bread; Composition; Varieties, 244, 246. Methods of E.xamination, 246, 247. 
Adulteration of Bread; .A.lum, 248. Cake, 249. 

Leavening Materials; Yeast, 249. Compressed Yeast; Dn.' Yeast, 250. Com- 
position and Microscopical Examination, 251. Yeast Testing; Available Carbon 
Dioxide, 252. Starch in Compressed Yeast, 253. 

Chemical Leavening Materials; Baking Powders, their Classification and Com- 
position, 254, 256. Adulteration, 256, 257. Cream of Tartar and its .'Adultera- 
tion, 257. Analysis of Baking Chemicals, 258. Carbon Dioxide, 258-261. Tar- 
taric .Acid, 261. Starch, 262. ."Muminum Salts, 263. Other Ingredients, 263- 
265. 

Semolina, Maccaroni, and Edible Pastes, 266. Prepared Cereal Breakfast 
Foods; Nature and Composition, 267, 268. Analytical Methods, 269. Infants' 
and Invalids' Foods; Classification, 269. Composition, 270. .'Analytical Meth- 
ods, 271-273. 

References on Cereals, \'egetables, etc., 273. 

References on Leavening Materials, 275. > 



X TABLE OF CONTENTS. 

CHAPTER X. 

PAGE 

Tea, Coffee, and Cocoa 276-309 

Tea; Varieties, Method of Manufacture, Composition, 276-279. Analytical 
Methods, 279. Theine, or Caffeine, 280. Tannin, 281. Extract, 283. Adultera- 
tion and Detection of Adulterants, 284. Facing, 284. Spent Leaves; Foreign 
Leaves, 285. Stems and Fragments, 286. Added Astringents; Tea Tablets, 287. 
Microscopical Structure, 2S8. 

Coffee; Nature, Composition, Effect of Roasting, 289, 290. Analytical Meth- 
ods, 291. Adulteration, 292. Microscopical Examination, 293. Chicory; its 
Microscopical Structure, 294. Composition of Chicory, and its Determination 
in Coffee, 296. Date Stones, 297. Glazing; Coffee Substitutes, 298. 

Cocoa and Cocoa Products; Composition, Methods of Manufacture, 299- 
301. Theobromine and Nitrogenous Substances, 302. Analytical Methods, 302- 
30J. Cocoa Butter, 304. Adulteration, and Standards of Purity, 304. Addition 
of Alkali, 305. Microscopical Structure, 306. Cocoa SheUs, 307. Added Starch 
and Sugar, 308. 

References on Tea, Coffee, and Cocoa, 30S. 

CHAPTER XI. 

Spices 310-367 

Methods of Proximate Analysis Common to all the Spices, 310. Moisture; Ash; 
Ether, and .-Mcohol Extract; Nitrogen; Starch; Crude Fiber; Volatile Oils, 31 1-3 13. 
Microscopical Examination, 314. 

Cloves; Composition, 314-317. Tannin, 317. Microscopical E.xamination, 318. 
Clove Stems, 319. Adulteration and Standard of Purity, 320. Exhausted Cloves, 
320. Cocoanut Shells, 321. 

.Allspice; Composition, 322. Tannin Equivalent, 323. Microscopical Struc- 
ture, 324. .adulteration and Standard of Purity, 326. 

Cassia and Cinnamon; Composition, 326. Microscopical Structure, 328. Adul- 
terants; Standard, 330. Foreign Bark, 330. 

Pepper; Composition, 330-333. Nitrogen Determination, 334. Piperin, 335. 
Microscopical Examination, 335. .Adulteration and Standards, 337. Pepper 
Shells and Dust, 337, 338. Olive Stones, 338. Buckwheat, 339. Long Pepper, 

34°- 

Cayenne; Varieties, Composition, 341. Microscopical Structure, 343. Adulter- 
ants and Standard of Purity, 344. Mineral .\dulterants, 344. Ground Red- 
wood, 345. .-Vrtificial Colors, 345. 

Ginger; Composition, 345, 346. E.xhausted Ginger, and its Detection, 347, 
348. Microscopical Structure, 349. .\dulteration and Standard, 350. 

Turmeric; Composition, 350. Microscopical Structure, 351. Detection, 353. 

Mustard; Composition, 353-356. Preparation, 354. Mustard Oil Determina- 
tion, 357. Microscopical Structure, 358. .Adulteration and Standards, 359. Col- 
oring Matter, 360. 

Nutmeg and Mace; Composition of Nutmeg, 360, 36r. Microscopical Structure 
of Nutmeg; Adulteration; Standard of Purity, 362. Composition of Mace, 363. 
Microscopical Structure; .Adulteration; Standard, 364. Bombay or Wild Mace 
and its Detection, 365. Mace Oils; Macassar Mace, 366. 

References on Spices, 366. 



T/IBLE OF CONTENTS. 



CHAPTER XII. 

PACE 

Edible Oils and Fats 368-460 

Nature and Properties, 368. Fatty Adds, 368, 369. Saponification, 369. Anal- 
ysis and Judgment as to Purity, 370. Filtering, Weigliing, and Measunng Fats, 
370. Specific Gravity, 371. Viscosity, 374. Melting-point, 374. Reichert-Meissl 
Process for Volatile Fatty Acids, 375. Soluble and Insoluble Fatty Acids, 377-379. 
Saponification Number, 379. Iodine Absorption Number; Hiibl's Method, 380. 
Hanus's Method, 383. Wijs's Method, 384. Bromine Absorption Number, 385. 
Thermal Tests, 385. Maumene Test; Bromination Test, 386. The Refractome- 
ter; Varieties, 389. Butyro-refractometer and its Manipulation, 390-394. Com- 
parative Refractometer Scale, 396. The Abbe Refractometer, 397. Butyro- 
readings of Fats and Oils, 398. The Acetyl Value, 400. The Valenta and Elaidin 
Tests, 402. Free Fatty .\cids, 402. Titer Test, 403. Unsaponifiable Matter, 
403. Cholesterol and Phytosterol, 404-408. Paraffin, 409. Microscopical E.x- 
amination of Oils and Fats, 409. Constants of Edible Oils and Fats, 410. 

Olive Oil, 412. Composition and Adulteration, 413. Standards, 414. Tests 
for Adulteration, 415-417. Cottonseed Oil, 417. Bechi's Test, 418. Halphen's 
Test, 419. Sesame Oil, 419. Adulterants and Tests, 420. Rape Oil, 421. Tests, 
422. Corn Oil, 422. Sitosterol, 423. Peanut Oil, 423. Adulterants; Re- 
nard's Method, 424. Bellier's Methods, 425. Mustard Oil, 426. Poppvseed 
Oil, 427. Sunflower Oil, 427. Rosin Oil, 428. Cocoanul Oil, 429. Cocoa 
Butter; Tallow, 430. 

Butter, 430. Composition, 431. Analytical Methods, 432. Ash; Casein; Milk 
Sugar; Lactic Acid; Salt, 433. Standard Butter Fat, 433. Adulteration, 434. 
Colors, 434, 435. Preservatives, 436, 437. Renovated or Process Butter; Oleo- 
margarine, 438. Distinguishing Tests for Butter, Process Butter, and Oleomarga- 
rine, 440, 441. Butyro-refractometer, 443-445. Reichert-Meissl Number, 445. 
Specific Gravity; Foam Test; Milk Test, 446. Curd Tests, 447. Microscopical 
Examination, 448. Foreign Oils; Glucose, 450. Adulteration of Oleomargarine, 

451- 

Lard, 451. Composition, 452. Lard Oil; Compound Lard, Standards, 453. 
Adulteration, 453. Foreign Oils, 454. Microscopical Examination, 454. .\naly- 
sis of Lard and Lard Substitutes, 456. 

References on Edible Oils and Fats, 457. References on Butter, 458. Refer- 
ences on Lard, 459. 



CHAPTER XIII. 

Sugar and Saccharine Products 461-522 

Nature and Classification, 461. Cane Sugar, 462. The Sugar Cane; Manu- 
facture of Cane Sugar, 463. Composition of Cane Sugar Products, 464. The 
Sugar Beet; Manufacture of Beet Sugar, 465. Refining .Sugar; Maple Products, 
466. Adulteration of Maple Products, 467. Sorghum, 468. Grape Sugar, 468. 
Levulose; Malt Sugar, 469. Dextrin; Commercial Glucose, 470. Milk Sugar; 
RafBnose, 472. 

The Polariscope and Saccharimetry, 473-478. Comparison of Scales and 
Normal Weights, 478. Specific Rotary Power; Birotation, 479. 

Analysis of Cane Sugar and its Products; Tests for Sucrose, 480. Moisture; 
Ash; Non-sugars, 481. Sucrose Determination by Polariscope, 481. Inversion, 
483. Volumetric Fehling Process, 486. Gravimetric Fehling Methods, 488— 
497. Electrolytic Apparatus, 493. 



xii TMBLE OF CONTENTS. 

PAGE 

Analysis of Molasses and Syrups, 498-503. Double Dilution Method of 
Polarizing, 503. Raffinose Determination, 503. Adulteration of Molasses, and 
Standards, 504. Glucose Determination, 505. Tin Determination, 507. 

Separation and Determination of Various Sugars, 507, 508. Analysis of Glu- 
cose, 509. Arsenic in Glucose, 511. 

Honey, 511. Composition and Adulteration, 512, 513. Glucose in Honey, 514. 
Beeswax, 515. Confectionery; Standard; Adulteration, 517. Analysis of Con- 
fectionery, 518-521. 

References on Sugars, 522. 

CHAPTER XIV. 

AicoHOLic Beverages 523-607 

Alcoholic Fermentation, 523. Alcoholic Liquors and State Control, 524. Liquor 
Inspection, 525, 526. Analytical Methods, Common to all Liquors, 527. Detec- 
tion and Determination of Alcohol, 528. Alcohol Tables, 531-544. The Ebulio- 
scope, 545. Extract; Ash; Artificial Sweeteners, 547. 

Fermented Liquors; Cider, 548. Manufacture and Composition, 549-551. 
Adulteration, 552. Perry, 553. Wine, 554. Classification of Wines, 555. Com- 
position and Varieties, 556-558. Standards, 559. Adulteration, 560-563. Analyt- 
ical Methods for Wine; Extract; Acidity, 564. Tartaric Acid, 568. MaUc Acid, 
569. Sugars; Glycerin; Tannin, 570-571. Foreign Colors, 571-573. 

Malt Liquors; Beer, 574. Varieties of Beer and Ale, 575. Composition, 576. 
Malt and Hop Substitutes, 577. Adulteration and Standards, 578. Malted vs. 
Non-malted Liquors, 578, 579. Preservatives; Arsenic; Temperance Beers, 580. 
Analytical Methods; Extract; Original Gravity, 581-587. Acids; Proteids; 
Phosphoric Acid, 588. Carbon Dio.xide, 589. Bitter Principles, 590. Arsenic, 
591. Malt Extract, 592. 

Distilled Lif|Uors, 593. Fusel Oil, 594. Whiskey; Composition, .Adultera- 
tion, 594-596. Brandy; Manufacture, Adulteration, 597, 598. Rum, 599. Gin, 
600. Analytical Methods for Distilled Liquors; Fusel Oil, 601. Ethereal Salts; 
Furfurol; Caramel, 603. 

Liqueurs and Cordials, 605. Analysis of liqueurs, 606. 

References on Alcoholic Beverages; on Beer, 607. 

References on Cider and Wine; on Distilled Liquors, 608. 

CHAPTER XV. 

Vinegar 609-627 

Acetic Fermentation; Varieties of Vinegar, 609. Manufacture and Composition, 
610-611. Cider Vinegar, 610. Wine Vinegar, 611. Malt Vinegar, 612. Spirit, 
Glucose, and Molasses Vinegars, 613. Wood Vinegar, 614. Analytical Methods; 
Density; E.xtract; Ash; Phosphoric Acid, 614. Nitrogen; Acidity, 615. Alcohol; 
Mineral Acids, 616. Malic Acid, 617. Potassium Tartrate; Sugars, 618. 

Adulteration of Vinegar; Standards, 619. Artificial Cider Vinegar, 620. Char- 
acter of Residue and Ash, 620, 621. Character of Sugars, 622. Composition of 
Artificial Cider Vinegars, 623, 624. Detection of Adulterants, 625, 
References on Vinegar, 626. 



TylBlE OF CONTENTS. 



CHAPTER XVI. 

PACE 

Artificial Food Colors 628-660 

Extent of Use; Objectionable Features, 628. Toxic Effects, 629. Harmful 
Mineral Colors, 630. Harmful Organic Colors, 631. Harmless Mineral Colors; 
Harmless Organic Colors, 632-634. Use of Colors in Confectioner^-, 634. \'ege- 
table Colors, 635. Special Tests; Orchil; Logwood; Turmeric, 637. Caramel; 
Indigo, 638. Mineral Pigments; Prussian Blue; Cltraraarine; Lead Chromate, 638. 
Cochineal, 638. 

Coal-tar Colors, 639. Detection in Food; Basic and Acid Dyes; Wool Dyeing, 
640. Double Dyeing Method, 641. Vegetable Colors on Wool, 642. E.xtraction 
of Colors by Immiscible Solvents, 642. Separation with Ether, 643. Special 
Tests, 644. Classification and Identification of Coal-tar Dyes; Rota's Scheme, 
644-649. Direct Identification of Colors, 650. Table of Reactions for Colors 
on the Fiber, 652-659. 
References on Colors, 660. 

CHAPTER X\1I. 

Food Preservati%'es 661-681 

Preservation of Food, 661. Regulation of .\ntiseptics, 662. Commercial Food 
Preservatives, 663. Formaldehyde, 664. Determination in Preservatives, 665. 
Detection in Food, 666. Determination, 667. Boric Acid; Determination in Pre- 
servatives, 667. Detection in Foods, 668. Determination, 669. Salicylic .\cid; 
Detection, 671. Determination, 672. Benzoic Acid; Detection, 673. Sulphur- 
ous Acid; Detection, 675. Fluorides, Fluosilicates, Fluoborates, 676, 677. Beta- 
Naphthol; Detection, 677. .\saprol or ,'\brastol, 678. 
References on Preservatives and their Use in Food, 679. 



CHAPTER X\ail. 

Artificial Swekteners 682-688 

Extent of Use; Saccharin, 682. Detection of Saccharin, 683. Determination, 
684. Dulcin; Detection, 685. Determination of Dulcin, 686. Glucin, 687. 
References on .Artificial Sweeteners, 687. 



CHAPTER XIX. 

Canned and Bottled Vegetables, Relishes, and Fruit Products 689-756 

Canned Vegetables and Fruits, 689. Method of Canning, 690. Composition, 
and Methods of Proximate .\nalysis, 691. Decomposition and Detection of Spoiled 
Cans, 692. Gases from Spoiled Cans, 693. Metallic Impurities, 694. .\ction of 
Fruit .\cids on Tin Plate, 695-698. Salts of Lead and Zinc, 699. Salts of Copf)er; 
Greening by Copper Salts, 699. Salts of Nickel; Toxic Effects of Metallic Salts, 
701. Separation and Determination of Metallic Salts, 701-705. Antiseptics in 
Canned Foods, 705. Detection of Preservatives, 706. Soaked Goods, 707. 
Ketchups and Table Sauces, 708. Preservatives in Table Sauces, 710. Pickles 
and their .Adulteration, 711. Horseradish, 712. 

Jams and Jellies, 712. Composition and .Adulteration, 713-715. Adulterated 
Jams and Jellies, 716, 717. Labeling "Compound" Goods, 717. .Analytical 
Methods, 718. Determination of Sugars, 719-721. Glucose, 731. Dextrin; Tar- 



TABLE OF CONTENTS. 



722. Citric Acid; Coloring Matters, 723. Preservatives; Starch; 
Gelatin, 724. Apple Pulp; Microscopical Examination, 725. 

Fruit Juices, 725, 726. Sweet Cider; Lime Juice, 727. Fruit Syrups, 728. 

Flavoring Extracts, 728. Vanilla Extract, 729. Vanilla Bean; Vanillin, 730. 
Exhausted Vanilla Bean; Composition of Vanilla Extract, 731. The Tonka 
Bean; Coumarin, 732. Adulteration of Vanilla Extract; Artificial Extracts, 733. 
Detection of Artificial Extracts, 734. Methods of Determining VanilUn, 735. De- 
termination of Coumarin, 737. \'anillin and Coumarin under the Microscope; 
Glycerin, 73S. Adulterants, 739. 

Lemon Extract, 739-741. Analytical Methods, 741. Determination of Lemon 
Oil and Alcohol, 742. Methyl Alcohol, 743. Colors; SoUds; Ash; Glycerin; 
Examination of Lemon Oil, 744. Constants of Lemon and Other Essential Oils, 
745. Citral, Citronellal, and other Adulterants, 746. Miscellaneous Extracts, 747. 
Orange Extract, 748. 

Almond Extract, 74S. Benzaldehyde, 749. Nitrobenzol, 749. Separation and 
Determination of Benzaldehyde and Nitrobenzol, 750. Alcohol and Hydrocyanic 
Acid, 751. 

Artificial Fruit Essences, 751-753- 

References on Canned Foods, Fruit Products, and Flavoring Extracts, 754. 



APPENDIX. 

The Zeiss Immersion Refractometer, 757-763. Strength of Solutions by the Refractom- 
eter, 764. Detection of Added Water in Milk, 765-766. References on Immersion 
Refractometer, 767. 

Detection of Refined Cane Sugar in Maple Products, 767, 768. Polarization of Com- 
mercial Glucose, 769. Ash Data of Pure and .-adulterated Maple Products, 770. 



PLATES I-XL. 
Photomicrographs of Pure and Adulterated Foods and of Adulterants. 

Cereals: Barley, I. Buckwheat, II, III. Corn, III, IV. Oat, IV, V. Rice, V, VI. 
Rye, VI, VII. Wheat, VIII. 

Legumes: Bean, IX. Lentil, IX, X. Pea, X, XL 

Miscellaneous Starches: Potato; Arrowroot; Tapioca, XII. Turmeric; Sago, XIII. 

Coffee, XIV, XV. Chicory, XV, XVI. Cocoa, XVI, XVII. Tea, XVIII. 

Spices: Allspice, XVIII, XIX. Cassia, Cinnamon, XX-XXII. Cayenne, XXII-XXIV. 
Cloves; Clove Stems, XXIV-XXVII. Ginger, XXVII-XXI.X. Mace, XXI.X. Nutmeg, 
XXX. Mustard, XXXI-XXXIII. Pepper, XXXIII-XXXVI. 

Spice Adullerants: Olive Stones; Cocoanut Shells, XXXVI. Elm Bark; Sawdust; 
Pine Wood, X.XXVII. 

Edible Fats: Pure Butter; Renovated Butter; Oleomargarine, XXXVIII. Lard 
Stearin, XXXIX. Beef Stearin, XL. 



FOOD INSPECTION AND ANALYSIS. 



■ CHAPTER I. 
FOOD ANALYSIS AND STATE CONTROL. 
INTRODUCTORY. 

The general subject of food analysis, in so far as the public health is 
concerned, is to be considered from two somewhat different standpoints: 
first, from the outlook of the government, state, or municipal analyst, whose 
mission it is to ascertain whether or not the food may properly be con- 
sidered pure or free from adulteration; and second, from the point of view 
of the food economist, whose aim is to determine its actual composition 
and nutritive value. The one protects against fraud and injun,-, the 
other furnishes data for the arrangement of dietaries and for an intelligent 
conception of the role which the various nutrients play in the metabohsm 
of matter and energy in the body. The two fields are as a rule distinct each 
from the other, often involving, in the examination of the food, different 
methods of procedure. 

State Control of Food. — In view of the importance of the consideration 
of food with reference to its purity, an ever-increasing number of states 
are realizing the necessity of protecting their citizens from the unscrupu- 
lous manufacturers who in various lines are seeking to produce cheaper 
or inferior articles of food in close imitation of pure goods. Many of 
the states have laws in accordance with which the sale of such impure 
or adulterated foods is made a criminal offense, and some, but not all 
of these, are provided with public analysts and other officers to enforce 
these laws and punish the offenders. Numerous communities are awake 
to the importance of municipal control of such commonly used articles 
of food as milk, butter, and vinegar, and in many cases have machinery 
of their own for regulating the sale of these foods. 



2 FOOD INSPECTION AND ANALYSIS. 

Food Analysis from the Dietetic Standpoint. — The study of the prin- 
ciples of dietetics has been given increased attention during the last decade 
in the curricula of many of the technical schools and colleges. Much 
has been accomphshed by certain of the state experiment stations working 
as a rule in connection with the United States Department of Agriculture 
along this line. Investigations of this character are especially valuable, 
and are indeed rendered necessary by the general tendency of the modern 
physician to regard the hygienic treatment of disease, especially with 
reference to the matter of diet, as often of far greater importance than 
the mere administering of drugs. ^ 

The food economist studies the var^-ing conditions of age, sex, occupa- 
tion, environment, and health among his fellow men, with a view to show- 
ing what foods are best adapted to supply the special requirements of 
various classes. The quantity and proportion of protein, fat and carbo- 
hydrates, or of fuel value best suited for the daily consumption of a given 
class or individual having been determined, dietaries are made up from 
various food materials to supply the need with reference as far as possible 
to the taste and means of the consumer. 

Experiments are made on families, clubs, or individuals, representing 
various typical conditions of life, and extending over a given period, dur- 
ing which records are kept of the available food materials on hand and 
received during the term of the experiment, as well as of those remaining 
at the end. In the case of individuals, additional records may be kept 
of the amount and composition of the urine and feces. From such data 
the physiological chemist calculates the amount of nutrients utilized, 
and studies the metabohsm of material in the human body. 

Up to this point no very extensive apparatus is required, but if in 
addition the income and outgo of heat and energy are to be studied, which 
are important to a complete investigation of the economy of food in the 
body, the student will require a respiration calorimeter and its appurte- 
nances. The calorimeter is so constructed that an individual may be 
confined therein for a term of days under close observation and with 
carefully regulated conditions. Such an equipment involves a large 
expenditure and is to be found in but few laboratories.* 

It is not the purpose of the present work to go beyond the strictly 

* To the writer's knowledge there are at present but two such thoroughly equipped 
laboratories in the United States, one, for human food experiments, at Wesleyan University 
at Middletown, Connecticut, and the other for experiments with cattle, at the Pennsylvania 
State College. 



FOOD /tNMLYSlS AND STATE CONTROL. J 

chemical or physical processes involved in making the analyses by which 
the proximate components of the foods are determined. For more com- 
plete information in the field of dietary studies and the metabolism of 
matter and energy in the body, the student is referred especially to the 
investigations of Atwater and his coworkers, as published in the annual 
reports of the Storrs Experiment Station at Middletown, and in the bulle- 
tins of the U. S. Department of Agriculture, Office of Experiment Stations, 
a list of which is given at the end of Chapter III. 

SYSTEMATIC FOOD INSPECTION. 

The Functions of the State Analyst. — The public analyst is emploved 
by city, stale, or government to pass judgment on various articles of food 
taken from the open market by purchase or seizure, either by himself 
or by duly authorized collectors employed for the purpose. The sole 
object of his examination is to ascertain whether or not such articles of 
food conform to certain standards of purity fLxed in some cases by special 
law, and in others by common usage or acceptance. Such a public analyst 
need not concern himself with the dietetic value of the food or whether 
it is of high or low grade. It is for him to determine simply whether it 
is genuine or adulterated within the meaning of the law, and, if adulterated, 
how and to what extent. Aside from his skill as a chemist, it is often 
necessar}^ for him to possess other no less important quaUfications, chief 
among which are his ability to testify clearly and concisely in the courts, 
and to meet at any time the most rigid kind of cross-examination, it being 
of the utmost importance that he understand thoroughly the nature of 
evidence. 

U. S. Standards of Purity for Food Products.* — Under an act of 
Congress approved June 3, 1903, standards of purity for certain articles 
of food including meat and meat products, milk and its products, sugars 
and related substances, spices, and cocoa and cocoa products were later 
(Nov. 20, 1903) estabhshed as official standards for the United States 
by the Secretary of Agriculture. Schedules are yet to be adopted and 
are in process of preparation in the following classes: grains, fruits and 
vegetables, honey, fruit extracts, salad oils, salt, tea, coffee, fruit juices, 
alcohoHc and carbonated beverages, vinegar, presenatives, and coloring 
matters. 

Nature of the Analytical Methods Employed. — Usually but a small 
percentage of the samples submitted for examination are actually adulter- 

* U. S. Dept. of Agric, Off. of Sec, Circ. lo. 



.4 FOOD INSPECTION yIND /IN A LYSIS. 

ated. The analyst should, therefore, adopt for economy in time the 
quickest possible reliable processes for separating the pure from the 
impure, so that most of his attention may be devoted to the latter. 
The nature of the processes by which this is done varies with the foods. 
Experience soon enables one to judge much by even the characteristics of 
taste, appearance, and odor, though such superficial indications should be 
used with discretion. One or two simple chemical or physical tests may 
often suffice to establish beyond a doubt the purity of the sample, after 
which no further attention need be paid to it. 

A sample failing to conform to the tests of a genuine food must be 
carefully examined in detail for impurities or adulterants. While in 
most cases usage or experience suggests the forms of adulteration peculiar 
to various foods, the analyst should be on the alert to meet new conditions 
constantly arising. His methods are largely qualitative, since technically 
he need only show in most cases the mere presence of a forbidden 
ingredient, though for the analyst's own satisfaction he had best deter- 
mine the amount, at least approximately. 

In reporting approximate quantitative results in court, especially 
when they are calculated from assumed or variable factors, or when they 
are the result of judgment based on the appearance of the food under 
the microscope, the analyst should always be conservative in his figures 
by expressing the lowest or minimum amount of the adulterant, so as 
to give the defendant the benefit of any doubt. When exact standards 
are fixed by law, as in the case of total solids or fat in milk, for example, 
there is of course great necessity for preciseness in quantitative work. 

A full analysis of an adulterated food beyond establishing the nature 
and amount of the adulteration is entirely unnecessary, and in most 
instances adds nothing to the strength of a contested case, as twenty 
years' experience in the enforcement of the food laws in Massachusetts 
has shown. 

The responsibility resting upon the analyst is not to be lightly con- 
sidered, when it is realized that his judgment and findings constitute the 
basis on which court complaints are made, and the payment of a fine 
or even the imprisonment of the defendant may be the result of his report. 
Therefore he should be sure of his ground, knowing that his results are 
open to question by the defendant. Where court procedure is apt to be 
involved, a safe rule is for the analyst to consider himself the hardest 
person to convince that his tests are unquestionable, making every possible 
confirmatory test to strengthen his position and consulting all available 



FOOD ANALYSIS AND STATE CONTROL. 5, 

authorities before expressing his opinion; and finally, after being fully 
convinced that a sample is adulterated, and having so alleged, let him 
adhere to his statements and not waver in spite of the most rigid cross- 
examination to which he may be sulijected. 

While each state or municipality has its own peculiar code of regula- 
tions and restrictions concerning the duties of the analyst and other officials, 
these rules are in the main very similar. For instance, it is usually neces- 
sary, excepting in the case of such a perishable food as milk, for the analyst 
to reserve a portion of a sample before beginning the analysis, which 
sample, in the event of proving to be adulterated, shall be sealed, so that 
in case a complaint is made against the vendor, the sealed sample may, 
on applicati<in, be delivered to the defendant or his attorney. 

Adulteration of Food. — Except in special cases a food in general is 
deemed to be adulterated if anything has been mixed with it to reduce 
or lower its quality or strength; or if anything inferior or cheaper has 
been substituted wholly or in part therefor; or if any valuable constituent 
has been abstracted wholly or in part from it; or if it consists wholly or 
in part of a diseased, decomposed, or putrid animal or vegetable sub- 
stance; or if by coloring, coating, or otherwise it is made to appear of 
greater value than it really is; or if it contains any added poisonous 
ingredient. These provisions briefly expressed are typical of the general 
food laws found in the statute books of many of the states, though the 
verbiage may differ. Laws covering compound foods and special foods 
var\' widely with the locality. As to the character of adulteration, nine 
out of ten adulterated foods are so classed by reason of the addition of 
cheaper though harmless ingredients added for commercial profit, rather 
than by the addition of actually poisonous or injurious substances, though 
occasional instances of the latter are found. 

Authentic instances of actual danger to health from the presence of 
injurious ingredients are extremely rare, so that the question of food 
adulteration should logically be met largely on the ground of its fraudu- 
lent character. Indeed the commoner forms of adulteration are restricted 
to a comparatively small number of food products, the most staple articles 
of our food supply, such as flour and the cereals, eggs, fresh meat, fresh 
vegetables and fruit being rarely subject to adulteration. 

A T5rpical System of Food Inspection. — The efficiency of a system 
of public food inspection is greatly enhanced if the business part of the 
work, including the bookkeeping and attending to the outside public, 
be done wholly through some person other than the analyst, as, for example, 



FOOD INSPECTION AND ANALYSIS. 




Fig. I. — Inspectors' Lockers. Insuring safe legal delivery of samples collected by three 
inspectors. Each locker has a door in the rear accessible, from an anteroom, to the in- 
spector holding key to that locker only. 



FOOD ANALYSIS AND STATE CONTROL. 



a health officer, to whom the collectors of samples and the analyst may 
report independently as to the results of their work, and whf)se duty it 
is to determine what shall be done in cases of adulteration. In this way 




Fig. 2. — Inspectors' Lockers. Front View. The lockers are accessible to the analyst in the 
laboratorj- by a single sliding-sash front, provided with a spring lock. The removable 
sliding-racks are convenient for returning clean sample bottles. 

the analyst .knows nothing of the data of collection nor the name of the 
person from whom the sample was purchased, so that he can truthfully 
state in court that his analysis was unbiased. 



P FOOD INSPECTION AND ANALYSIS. 

Suppose, for example, that three collectors are employed to purchase 
samples of food for analysis, their duties being to visit at irregular intervals 
different portions of a state or municipality. Each collector keeps a 
book in which he enters all data as to the collection of the sample, includ- 
ing the name of the vendor, assigning a number to each sample, which 
number is the only distinguishing mark for the analyst. One collector 
may use for this purpose the odd numbers in succession from i to 9999, 
the second the even numbers from 2 to 10,000, while the third may use 
the numbers from 10,000 up. Each of the two former would begin with a 
lettered series, as, for instance, A, numbering his samples lA, 3A, 5A, 7A, 
etc., or 2A, 4.^, 6A, etc., till he reached 10,000, then beginning on series 
B and so on. If the analyst is to be kept in ignorance of the brand or 
manufacturer in the case of package goods, the collector must remove 
from the original package sufficient of the sample for the needs of the 
analyst, and deliver it to the latter in a plain package, bearing simply the 
name under which the article was sold and the number. Such precau- 
tions are, however, not always practicable and depend largely on local 
regulations. The analyst reports the result of the analysis of each sample 
with the number thereof on a library card, with appropriate blanks both 
for data of analysis and for data of collection, the latter to be filled by 
the collector from his book after the analyst has handed in the card with 
the data of analysis. This system of recording and reporting analyses 
has been successfully used for years by the Department of Food and 
Drug Inspection of the Massachusetts State Board of Health. 

Legal Precautions. — The laboratory of the public analyst should 
preferably be provided with a locker for each collector, to which access 
may be had only by that collector and the analyst, so that in the absence 
of the latter, or when circumstances are such that the samples cannot be 
defivered to him personally, there may be such safeguards with respect 
to lock and key as to leave no ciuestion in the courts as to safe dehvery 
and freedom from accidental tampering. 

Such a system of lockers for use with three collectors is shown in 
Figs. I and 2. The same careful attention should afterwards be given to 
keep the specimens in a secure place both before and during the process 
of analysis, and to label with care all precipitates, filtrates, and solutions 
having to do with the samples, especially when several processes arc 
being simultaneously conducted, in order that there may be no doubt 
whatever as to their identity. The importance of precautions of this 
kind in connection with court work can hardly be too strongly emphasized. 



FOOD ANALYSIS AND STATE CONTROL. 9 

Practical Enforcement of the Food Law. — In the case of foods actually 
found adulterated, there are three practical methods of suppressing their 
further sale, viz., by pubhcation, by notification, and by prosecution. These 
may be separately employed or used in connection with each other, accord- 
ing to the powers conferred by law on the commission, board, or oflicial 
having in charge the enforcement of the law, and according to the dis- 
cretion of such official. 

Publication. — Under the laws of some states, the only means of pro- 
tecting the people lies in publishing hsts of adulterated foods with their 
brands and manufacturers' names and addresses in periodical bulletins 
or reports. Sometimes it is considered best to publish for the informa- 
tion of the public lists of unadulterated brands as well, and, again, it is 
held that only the offenders should thus be advertised. 

Such publication, by keeping the trade informed of the blackhsted 
brands and manufacturers, certainly has a decidedly beneficial effect 
in reducing adulteration, and involves less trouble and expense than 
any other method. It is obviously an advantage, however, in addition 
to this to be able in certain extreme cases to use more stringent methods 
when ncccssar}'. 

Notification and Prosecution. — The adulteration of food is best held 
in check in localities where under the law cases may be brought in court 
and are occasionally so brought. The mere power to prosecute is in 
itself a safeguard, even though that power is not frequently exercised. 
Under a conservative enforcement of the law, actual prosecution should 
be made as a last resort. Neither the number of court cases brought 
by a food commission nor the large ratio of court cases to samples found 
adulterated are criteria of its good work. Except in extreme cases, 
it is frequently found far more effective to notify a violator of the law, 
especially if it is a first offense, giving warning that subsequent infraction 
will be followed by prosecution. Such a notification frequently serves 
to stop all further trouble at once and with the minimum of expense. 
Instances are frequent in Massachusetts where, by such simple notifica- 
tion, widely distributed brands of adulterated foods have been immediately 
withdrawm from sale. 

Massachusetts was the first of all the states to enact pure-food legisla- 
tion, and for twenty years has enjoyed a well-established system of food 
inspection, prosecuting cases under its laws through the Food and Drug 
Department of the State Board of Health. Cases are brought in court 
with practically no expense for legal services. Complaints are entered by 



lo FOOD INSPECTION AND ANALYSIS. 

the collector, or, as he is termed, inspector, who makes complaint not in 
his official capacity, but as a citizen who under the law has been sold a 
food found to be adulterated, and who is entitled to conduct his own 
case, which he does with the aid of the analyst and such other witnesses 
as he may see fit to employ. Experience is readily acquired by the inspector 
in conducting such cases in the lower police or municipal courts, where 
they are first tried, and years ago the services of legal counsel in Massa- 
chusetts were dispensed with as superfluous.* 

Statistics in the annual reports of the Massachusetts Board show with 
what uniform success these trials have been conducted. While more 
often settled in the lower courts, occasional appeal cases are carried to 
the superior courts, where the services of the regular district attorney are 
of course availed of in prosecuting the case. 

REFERENCES ON FOOD INSPECTION AND STATE CONTROL. 

Abbott, S. W. Food and Drug Inspection. Article in Reference Handbook of the 

Medical Sciences, Vol. 3, pp. 162-180. N. Y., 1902. 
Andrews, O. W. Public Health Laboratory Work and Food Inspection. London, 

1901. 
BiGELOW, W. D. Foods and Food Control. U. S. Dept. of Agric , Bur. of Chem., Bui. 

69. 
Pure Food Laws of European Countries. U. 8. Dept. of Agric, Bur. of Chem., 

Bui. 61. 
BucHKA, K. VON. Die Nahrungsmittelgesetzgebung im Deutschen Reiche. Berlin, 

1901. 
Chapin, C. V. Municipal Sanitation in the United States. Providence. 
Kenwood, H. R. Public Health Laboratory Work. London, 1904. 
Leach, A. E. Character and Extent of Food and Drug Adulteration in Massachu- 

setts and the System of Inspection of the State Board of Health. Tech. Quar- 
terly, March, 1900. 
Mode, C. D. Suggested Standards of Purity for Foods and Drugs. London, 1902. 
PoLiN ET Labit. E.xamen des Aliments suspects. Paris, 1892. 
TrrcKER, W. G. Food Adulteration: Its Nature and Extent and How to Deal with 

It. Med. Rev. of Rev's, Oct., 1903. 
Vacher, F. The Food Inspector's Handbook. London, 1893. 
Wedderbxirn, A. J. Reports on Extent and Character of Food and Drug Adulteration, 

in the United States. U. S. Dept. of Agriculture, Div. of Chem., Bulletins 25, 

32, and 41. 
WtJRZBtmG, A. Die Nahrungsmittelgesetzgebung im Deutschen Reiche. Leipzig. 1903. 

* \Vhere such a practice is in vogue an intelligent inspector must of course be chosen 
with reference to his ability to do this court work. The food laws are few and simple, as 
are also the court decisions rendered under them, so that it is no great task for the inspector 
to become much more familiar with them than the average general lawyer whom he meets 
in court and who not infrequently consults the inspector for information regarding these laws. 



FOOD ANALYSIS AND STATE CONTROL. II 

The British Tood Journal, London, 1899 ft scq. 

Food and Sanitation, London, 1892-19C50 (discontinued August, 1900). 

Journal of the Sanitary Institute, 1892 et seq. 

Revue International des Falsifications, Amsterdam, 1888 et seq. 

Veroffentlichungen de . kaiserlichen Gesundheits.imptes. Berlin, 1877 et seq. 

Arbeiten aus dem kais rlichen Gesundheitsamptes. Berlin, 1886 et seq. 

Reports of the Local Government Board of England, 1877 et seq. 

Reports of the Paris Municipal Laboratory, 1882 and 1885. 

Reports of the Canton Chemists of Switzerland, 1890 et seq. 

Annual Reports of the Massachusetts State Board of Health, 1883 et seq. 

Monthly Bulletins of the Massachusetts State Board of Health. 

Annual Reports of the Conn. Agric. Exp. Station on Food Products, 1896 et seq. 

Annual Reports of the Ohio Dairy and Food Commissioner, 1890 et seq. 

Annual Reports of the New Jersey Dairy Commissioner, 1886 et seq. 

Annual Reports of New Jersey Laboratory of Hygiene, Chemical Dept., 1903 et seq. 

Annual Reports of the Michigan Dairj' and Food Department, 1893 et seq. 

Monthly Bulletins of the Michigan Dairy and Food Department, Aug., 1895 et seq. 

Biennial Reports of the Minnesota Dairy and Food Commissioner. 

Annual Reports of the Wisconsin Dairy and Food Commissioner, 1890 et seq. 

Annual Reports of the Penn. Board of Agriculture, 1894 et seq. 

Annual Reports of the Illinois State Food Commissioner, 1899 et seq. 

Biennial Reports of the New Hampshire State Board of Health, 1902 et seq. 

Quarterly Bulletins of the New Hampshire State Board of Health, 1902 et seq. 

Annual Reports of the North Carolina State Board of Agriculture on Food Products, 

1900 et seq. 
Bulletins of the North Dakota E.xperiment Station. 
Proceedings of the National Association of State Dairy and Food Departments, 1902 

et seq. 



CHAPTER II. 
THE LABORATORY AND ITS EQUIPMENT. 

Location. — The selection of a location for a food laboratory cannot 
always be made solely with reference to its needs and its convenience, 
but it is more often subject to economic conditions beyond the analyst's 
control. Under very best conditions, such a laboratory should be situated 
in a building designed from the start exclusively for chemical or biological 
and chemical work. Almost any well-lighted rooms in such a building 
can be readily adapted for the purpose. When, however, as is frequently 
the case, rooms for such a laboratory are provided in municipal, govern- 
ment, or office buildings, in which for the most part clerical work is done, 
the problem of adequately utilizing such rooms so that they may not 
at the same time prove offensive to or interfere with the comfort of other 
occupants of the building is sometimes difficult. It is obvious that base- 
ment rooms in such a building, as far as ventilation is concerned, are less 
readily adapted for the requirements in hand than are those of the top 
floor, though, if the light is good and there are abundant and well-arranged 
ventilating-shafts, such rooms may be made to serve every purpose. In 
the basement one may most easily obtain water, gas, and steam, and 
dispose of wastes without annoyance to one's neighbors. When, how- 
ever, it is possible to do so, rooms on the top floor of an office building 
should be utilized for a food laboratory, for in such rooms the problems 
of lighting, heating and ventilating are comparatively simple and may 
usually be solved without regard to other occupants. In such a case 
ample provision must be made, preferably through shafts which are 
readily accessible for water-, gas-, steam-, and soil-pipes ])assing down 
below. 

The actual equipment of the food laboratory' depends of course largely 
on its particular purpose; and while it is manifestly impossible to do other- 
wise than leave the details to the individual taste and needs of the analyst, 



THE L/IBOR/tTORY /4ND ITS EQUIPMENT. 13 

modified by the means at his disposal, a few general suggestions regarding 
important essentials may prove helpful. These imply a fairly liberal 
though not extravagant outlay, with a view to saving both lime and energy 
by convenient surroundings well adapted to the work in hand. At the 
same time equally satisfactory work is possible under simpler conditions 
than those described. 

Floor. — The best material for the floor of the working laboratory 
is asphalt. Such a floor is firm but elastic, is readily washed by direct 
appHcation of running water, if necessary, and resists well the action of 
ordinary reagents. An occasional thin coating of shellac with lampblack 
applied with a brush gives the asphalt floor a smooth, hard surface and 
may be applied locally to cover spots and blemishes. 

Lighting. — The lighting of the rooms, if on the top floor, is best effected 
by both wall windows and skylights. North windows furnish the best 
light for the microscope; the skylight, when available, is the ideal light 
for the balance and for general laboratory work. 

Ventilalion by forced draft is a great convenience. For this purpose 
an exhaust-fan driven by an electric motor and controlled in speed by 
a fractional rheostat is admirable. Such a fan had best be located in a 
small closed compartment or closet near the centre of the series of rooms 
designed to be ventilated by it, and this closet should have directly over the 
fan an outlet-shaft passing through the roof of the building. With such 
a system, a series of branching air-ducts should radiate from the fan closet, 
conveniently arranged either above or along the ceiling and communicat- 
ing with the various hoods, closets, and rooms near the top. 

Benches. — The working benches should have wooden or glazed tile 
tops. White glazed tile, if properly laid, furnish a very clean, sanitar}', 
and resistant surface, besides being often convenient for color tests. If 
laid on a plank surface, the tiles should not be imbedded in cement, which 
swells the wood before drying out and results in a loose and often uneven 
surface. For best results the tiles should be first soaked in oil and then 
carefully laid in putty. 

When wooden bench tops are used they may be treated to advantage 
by staining with the following solutions: 

Solution I. 
100 grams of aniline hydrochloride. 
40 " " ammonium chloride. 
65 " " water. 



14 FOOD INSPECTION AND ANALYSIS. 

Solution 2. 

loo grams of copper sulphate. 

50 " " potassium chlorate. 
615 " " water. 

The solution should be applied to the bare wood. Soft wood gives a 
better finish than hard wood. Apply solution i thoroughly and allow it 
to drj'; then apply 2 and dry. Repeat these applications several times. 
Wash with plenty of hot soap solution, let dry and rub well with vaseline. 

It is claimed that wood so treated is rendered fire-proof and is not 
acted on by acids and alkalies. When the finish begins to wear, an appli- 
cation of hot soap solution or vaseline will bring it back to a deep black 
color. 

The benches should naturally be located with reference to best light 
from skylights or windows. Gas and water outlets, sinks and waste- 
pipes should be conveniently arranged with reference to the working 
benches, as well as suitable provisions for air-blast and exhaust, while 
in the space beneath the benches such drawers, cupboards, and receptacles 
as are required should be provided. If the benches are excessively wide, 
there is constant temptation to allow countless pieces of apparatus and 
reagent bottles not needed for immediate use to accumulate along the 
back spaces to the detriment of order and cleanliness. A clear bench 
width of 24 inches is ample for most work. At the back of the bench 
and within easy reach a raised narrow shelf should be provided to be used 
exclusively for common desk reagents. This again should not be so 
wide as to allow the accumulation of useless bottles. A narrow raised 
guard or beading at the edge of the reagent shelf prevents the bottles 
from accidentally slipping off. 

Hoods. — Closed hoods with sliding sash fronts are almost indispensable. 
These hoods should be directly connected with the ventilating shafts or 
pipes, or with the air-ducts that radiate from the exhaust-fan closet, when 
such a system is provided. Gas outlets inside the hoods are necessary. 

When there is a good draft either natural or forced, a hooded top 
over the working bench such as that shown in Fig. 3 is quite as efficient 
as a closed hood for most purposes. This is best made of galvanized 
iron, painted on the outside and treated on the inside with a preparation 
of graphite ground in oil. Here are best carried out aU the processes 
involving the giving off of fumes and gases, which, if the ventilation is 
efficient, should pass directly up the flues and not come out in the room. 



THE LABORATORY /IND ITS EQUIPMENT. 



•5 



Sinks and Drains. — The sinks should preferably be of iron or porce- 
lain. If iron, they should at frequent intervals be treated with a coat of 




Fig. 3. — Hooded Top of Galvanized Iron over Working-bench, Connected w-ith 
Ventilating .Air-ducts. 

asphalt varnish. A great convenience is a hooded sink (Fig. 4) in which 
foul-smelling bottles, or vessels giving off noxious or offensive fumes 



1 6 FOOD INSPECTION AND ANALYSIS. 

or gases, may be rinsed under the tap while completely closed in. Open- 
work rubber mats at the bottom of the sinks help to insure against break- 
age. Open plumbing of simplest design should be used, and a multi- 
plicity of traps should be avoided. Sinks may be variously located for 




I 

Fig. 4. — ^A Hooded Sink. An injector-like arrangement of steam and cold-water pipes. 
Furnishes water of any desired temperature. 



convenience without regard to situation of soil-pipes, if the floor is thick 
enough to allow an open drain with sufficient pitch to flow readily. Such 
open drains are much more readily cleaned than closed pipes, and are 
best constructed by splitting a lead pipe and laying it in an iron box which 
is sunk into the floor. The edges of the lead pipe are rounded over those 
of the box as in Fig. 5, filling the joints with hydraulic cement, and 
the top of the drain is covered by a series of readily removable iron plates 



THE L/tBOR.4rORY AND ITS EQUlhMENT. 



17 



flush with the top of the floor. Waste-pipes from sinks, still-condenscrs, 
refrigerators, and various forms of apparatus involving flowing water may 
be led into this drain, holes being drilled in the iron cover for their insertion. 
Steam and Electricity. — These are useful but not indispensable. Steam, 
when available, may be used to advantage for boiling ether or benzine 
in connection with continuous fat-extraction apparatus, for furnishing 
the motive power for driving the Babcock centrifuge, for heating water- 
baths and hot closets, and, in connection with cold water, to furnish a 




Fig. 5. — Section of Open Drain-pipe in Floor. 

supply of hot water when wanted at the sink. The latter application 
is illustrated in Fig. 4. 

If electricity is used for lighting, it may also be applied in a variety 
of useful ways in the laboratory, as, for instance, for heating coils or electric 
stoves, for electrolysis, and for running small motors, which in turn may 
be employed for driving centrifuges, shaking apparatus, ventilating-fans, 
air-pumps, etc. 

Suction and Blast. — If the water-pressure is ample, both air-pressure 
and exhaust for blast-lamps, vacuum filtration, and other pui-poses are 
readily available through the agency of the various devices used in con- 
nection with the flow of water, as, for instance, the Richards pump. \Vlien, 
however, the water pressure is insufficient, other means must be employed 
for furnishing these much-needed requisites. Fig. 6 illustrates a simple 
and almost noiseless pressure and exhaust pump run by a ^-H.P. electric 
motor, which with the pressure-equalizing tank and the appropriate 
connections are mounted on a light wheel truck, and readily movable 
to any part of the laboratory. By simply screwing the plug into an 



i8 



FOOD INSPECTION AND /ANALYSIS. 



electric-Hght outlet, either suction or blast may be had at wiU, depending 
on the position of a knife-edge switch which determines the direction of 
the current. By means of a fractional rheostat the speed may be varied 
and the pressure thus controlled. 




Fig. 6. — Portable Pressure- and Exhaust-pump Run by Electric Motor. 
lamps, vacuum filtration, etc. 



Useful for blast- 



APPARATUS. 

The laboratory is of course to be supplied with the usual assortment 
of test-tubes, flasks, beakers, evaporating and other dishes of porcelain, 
platinum and glass, funnels, casseroles, crucibles, mortars, burettes, 
pipettes, graduates, rubber and glass tubing, lamps, ring-stands and 
various supports, clamps and holders, the nature, number, and sizes of 
which are determined by individual requirements. Special forms of 
apparatus peculiar to certain processes of analysis or to the examination 
of special foods will be described in their appropriate connection. The 
following apparatus of a general nature may be regarded as indispensable 
for the proper fitting out of the food laboratory: 

Balances. — ^These should include (i) an open pan balance for coarse 
weighing, having a capacity up to i kilogram and sensitive to o.i gram, 
with a set of weights; and (2) an analytical balance, enclosed in a case, 
sensitive to .0001 gram under a load of 100 grams, with an accurate set 
of non-corrosive weights. The short-beam analytical balance is prefer- 



THE LABOR/tTORY AND ITS EQUIPMENT. 



19 



able for quick work, and as constnicted by the best modern makers leaves 
nothing to be desired. 

The Waler-bath. — This is such an important accessory to the food 
analyst that it should, if possible, be specially designed to meet his require- 




FlG. 7. — Water-bath, Enclosed in Hood, with Sliding-sash Front. 

ments, though the ordinarj' copper baths, supported on legs and designed 
to be heated by gas-burners, as kept in regular stock by the dealers, will 
sometimes serve the purpose. For nearly all moisture determinations the 
platinum dishes described on page 97 and the somewhat larger wine-shells 
of 100 cc. capacity are most used, and for this purpose the top of the 
bath should have plenty of openings of the right size for these. A very 
economical construction of bath admirably adapted for the food analyst's 
use is shown in plan in Fig. 8, being the form employed by the writer. 



FOOD INSPECTION AND ANALYSIS. 



The size and number of openings are determined by the number of 
samples to be simultaneously analyzed. The dotted lines indicate a steam ■ 
coil within the body of the bath, which serves to boil the water. Fig. 7 
shows the bath in place within a hood, the sliding front of which is fur- 
nished with a hasp and padlock, so that it may always be kept locked by 
the analyst whenever he is temporarily absent from the laboratory. This 
is a useful precaution, when the residues left thereon are from samples 
which are to form subjects for possible prosecution in court later. 



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Fig. S. — Plan View of Water-bath Boiled by Steam-coil. IT' and 11'' are water inlet and 
outlet, S and S' steam inlet and outlet, respectively. 

Steam, if available at all seasons of the year, furnishes a ready means 
of heating the bath. Electric immersion coils are also convenient. In the 
absence of both steam and electricity, the Ijath must be boiled by gas- 
burners. 

Tlie Drying-oven. — A convenient form of asbestos-covered, jacketed 
air-oven, having removable shelves and heated by a gas-burner is shown in 
Fig. 9, with an efficient form of gas-pressure regulator. The particular 
form of low burner best adapted for use with the oven is also shown. Such 
an oven may also be heated by an electric coil, the temperature being 
governed by a rheostat of delicate construction. 

The Watcr-stUl. — An efficient still should be provided, capaljle of 
supplying the laboratory with an ample quantity of pure water for analyti- 
cal purposes. Fig. lo illustrates a compact form of still, which is particu- 
larly economical in view of the fact that a single stream of inflowing cold 



THE LABORATORY AND ITS KQUIPMHNT. 2 1 

water first serves to cool the condenser, and, rising, becomes \a|)orized 
in the boiler directly connected with the condenser at the top. This 
apparatus is capable of distilling six gallons of water in twelve hours. 




Fig. 9. — Asbestos-covered Air-oven, with Gas-pressure Regulator. 



The list of indispensable requisites in addition to the above should 
include the following: 

Continuous Extraction Apparatus (p. 57). 

Apparatus jor Nitrogen Determination (p. 62). 

Apparatus jor Distilling Various Food Products (pp. 63 and 530). 

A Babcock or other Milk-jat Centrijuge (p. loi). 

A Butyro Rejractonieter (Fig. gi). 

A Microscope and its Appurtenances (p. 71). 

A Polariscope and its Accessories (Figs, gg, 100, or loi). 

Apparatus for Specific Gravity Determination (pp. 50 to 54). 

Apparatus jor the Determination oj Carbon Dioxide (Fig. 65). 

Apparatus jor the Determination oj Melting-points (Fig. 86). 

Marsh Arsenic Apparatus (p. 66). 

Electrolytic Apparatus (Figs. 108 and log). 

Separatory Funnels (p. 60). 

Following is a list of apparatus and appliances which, while not indis- 
pensable, are convenient and at times desirable: 



2 2 FOOD INSPECTION AND ANALYSIS. 

A Spectroscope, either of the direct-vision variety for the pocket, or 
the Kirschoff & Bunsen style on a stand. 

Spectroscope Cells, parallel-sided, for observation of absorption spectra. 
A Photomkrographic Camera and Appurtenances* (pp. 84 to 86). 
A Muffle Furnace, 




Fig. 10. — A Convenient Laboratory' Water-still with Earthenware Receptacle, Provided with 

Faucet and Glass Gauge. 

An Incinerator jor the Simultaneous Ignition oj a Large Number oj 
Residues (p. 133). 

An Ebullioscope (Fig. 112). 

An Assay Balance, sensitive to .00001 gram for weigliing arsenic 
mirrors in capillary tubes. 

A Wollney Milk-fat Rejractometer (p. 103). 

An Abbe Rejractometer (Fig. 94). 

An Immersion Rejractometer (Fig. 120). 

* A photographic dark room is also necessarj' if pho'.omicrographic work is to be done. 



THE LABORATORY AND ITS EQUIPMENT. 



23 



A Universal Ccnlrijuge. — This convenient apparatus merits a separate 
brief description, being useful for a wide variety of purposes, such as 
breaking up ether- and other emulsions, cjuickly settling out precipitates, 
and roughly estimating chlorides, sulphates, phosphates, etc., by the 
volume of the precipitate in graduated tubes. Various-sized aluminum 
frames, carrying hinged shields, arc interchangeably adjustable to the 




Fig. II. — The Universal Centrifuge. Driven by an electric motor. 



spindle of a vertical electric motor.* The smallest frame has shields 
adapted to hold two graduated glass tubes of 15 cc. capacity (see Fig. 11). 
This is for the quantitative estimation of small precipitates and the quick 
settling oi sediments. A medium-sized and large frame carr\' tubes of 
80 cc. an.d 120 cc. capacity respectively. A frame is also provided 
with shields adapted for various-sized beakers to be used in settling pre- 
cipitates. The milk-fat centrifuge frame shown in Fig. 36 is also 
adapted to be used on the spindle of the same motor. 

* In the absence of electricity a water-motor may be used. 



24 



FOOD INSPECTION AND ANALYSIS. 



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26 



FOOD INSPECTION AND ANALYSIS. 



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THE LABORATORY AND ITS EQUIPMENT. 



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Dissolve 50 grams KI in H2O, add saturated HgCl2 solu- 
tion No. 173 to a distinct red precipitate. Add 350 
cc. of a solution of KOH containing 500 grams per 
liter, make up to a liter and allow to settle, using 
clear solution. 

Page 422. 


B.P. 35° C. and under for extraction in separatory funnel. 
B.P. 35° to 50° C. for Soxhlct extraction. 
B.P. 50° C. and over for cleansing. 

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THE LABORATORY AND ITS EQUIPMENT. 



20 



Dissolve I 20 grams sodium phosphate and 200 of sodium 
tungstate in i liter of H2O and add 100 cc. of cone. 
H2SO4. See also No. 20. 

Properly hydrochloroplatinic acid. 




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Dissolve I gram of fuchsin in H2O, add a mixture of 20 cc. 

NaHS03 solution No. 234 and 10 cc. HCl No. 8. 

Make up to i liter. 
See page 81. 




Standardize against No. 238. 
See page 258. 
Keep under petroleum. 
See Rochellc salt. No. 225. 


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FOOD INSPECTION AND ANALYSIS. 



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THH LABORATORY AND ITS EQUIPMENT. 



31 



REAGENTS. 

The foregoing list includes the general reagents used in carrying 
out the processes treated of in this volume, together with their strength, 
mode of preparation when necessary, and other data. 
Reagents, especially those constantly employed, should 
be assigned to regular places on the shelves, and 
should inyariably be kept in place when not in use. 

Among the standard solutions for volumetric work, 
none is more frequently of service in the food labora- 
tory than a tenth-normal solution of sodium hydrox- 
ide, and a large supply of this reagent, carefully 
standardized, should be at all times conveniently at 
hand. Besides being useful for standardizing tenth- 
normal solutions, it is constantly needed for deter- 
mining various acids in food products, such as milk, 
vinegar, butter, lime juice, cream of tartar, liquors, 
and many others. Time is well spent in carefully ad- 
justing this solution to its exact tenth-normal value, 
thus simplifying the calculation of results. A large 
stock bottle (say of two gallons capacity) containing 
the standard tenth-normal sodium hydroxide, is con- 
veniently mounted with a side-tube burette in con- 
nection, in some such manner as shown in Fig. 12. A 
small connecting side bottle contains a strong solution 
of sodium hydroxide (reagent No. 240) through which 
the air that enters the large bottle is passed, thus depriving it of CO,. 
In this manner the standard solution may readily be kept of unvar}-ing 
strength for a year or more. 




Fig. 12.— Stock Bot- 
tle of Tenth-normal 
Alkali. 



32 FOOD INSPECTION AND AN/I LYSIS. 



EQUIVALENTS OF STANDARD SOLUTIONS. 

No. 31. Decinoemal Sulphuric Acid. One cc. is equivalent to 

Ammonia gas NH3 0.0017 gram 

Ammonia NH.OH 0.0035 

Ammonium carbonate (NHJ.CO3 0.0046 

(NH^),C03,H,0 0.0057 

Calcium carbonate CaC03 o . 0050 

Calcium hydro.xide CaCOH), 0.0037 

" oxide CaO 0.0028 

Lead acetate Pb(C2H305.)5,3H,0 0.0189 

Magnesia MgO 0.0020 

Magnesium carbonate MgC03 0.0042 

Nitrogen N 0.0014 

Potassium acetate * KCoHjO, o . ooqS 

bicarbonate KHCO3 o.oioo 

bitartrate * KHC^HjO, o.oiSS 

carbonate KjCOj 0.0069 

citrate* K3CjH50j,H,0 0.0106 

hydroxide KOH 0.0056 

and sodium tartrate . KNaCjHj05,4H„0 0.0141 

Sodium acetate NaC,H30,,3H,0 0.0136 

" benzoate * NaCjH^O, 0.0144 

' ■ bicarbonate NaHC03 o . 0084 

" borate NaoB,0„ioH;0 o.oigi 

" carbonate NajCOj 0.0053 

Na2C03,ioH20 0.0143 

' ' hydroxide. '. NaOH o . 0040 

" salicylate* NaC7H503 0.0160 

No. 241. Decikokmal Sodium Hydroxide Solution. One cc. is equivalent to 

Acid, acetic H,C2H302 0.0060 gram. 

" boric H3BO3 0.0062 

" citric H3CeH,07,H20 0.0070 

" hydrobromic HBBr 0.0081 

" hydrochloric HCI 0.00365 

' ' hydriodic HI 0.0128 

' ' lactic HC3H5O3 o . oogo 

" malic CjHeOs 0.0067 

" nitric HNO3 0.0063 

" oxahc H,Cj04,2H,0 0.0063 

,, , , . -. __ \ to form K.HPO.with / 

phosphoric H.PO. 1 , ,■;,,. ," 0.0049 

' ■' * ( phenolphthalem I ^^ 

,, , , . „ „^ ( to form KH,PO,with > 

phosphoric H,PO. 1 , , " ,- 0.0098 

' I methyl orange ' 

' ' sulphuric H^SOj o . 0049 

" tartaric H,C,HjOe 0.0075 

Potassium bitartrate KHC,HjOe 0.0188 

Sodium borate Na^BjOjiioHoO 0.00955 

* To be ignited. 



THE LABORATORY AND ITS EQUIPMENT. 33 

No. 142. Df-CINORMAL Iodine Solution. One cc. is eiiuivalcnt to 

Arsenious o.xide ASjOj 0.00495 grain. 

Potassium sulphite KjS03,2H20 0.0097 

Sodium bisulpliite NaHSO^ 0.0052 

" sulphite NajSOjiVHoO 0.0126 

" thiosulphate NajEsOjiSHjO 0.0248 

Sulphur dioxide SO, 0.0032 

Sulphurous acid HjSOj 0.0041 

No. 245. Decinormal Sodium Thiosulphate Solution. One cc. is equivalent to 

Bromine Br 0.0080 gram. 

Chlorine CI 0.00355 " 

Iodine I 0.01266 " 

Iron (in ferric salts) Fe 0.0056 " 

No. 230. Decinormal Silver Nitrate Solution.* One cc. is equivalent to 

Ammonium bromide NH^Br o . 009S gram. 

" chloride NH,C1 0.00535 " 

Chlorine CI 0.00355 " 

Cyanogen (CN)„ 0.0052 " 

Hydrocyanic acid HCN with indicator 0.0027 " 

,,_,. ( to formation of precip- | 

" HCN- . (-0.0054 

( itate ' ^^ 

Hydrobromic acid HBr 0.0080 " 

Potassium bromide KBr o.oiig " 

" chloride KCl 0.00745 " 

' ' cyanide KCN with indicator o . 0065 ' ' 

„_^^ I to formation of precip- 1 

KCN- . '^ '. o.oi?o 

( itate \ -^ 

Sodium bromide NaBr 0.0103 " 

" chloride NaCl 0.00585 " 

No. 201. Decinormal Potassium Bichromate SoLUTiON.t One cc. is equivalent to 

Ferrous carbonate FeCOs 0.0116 gram. 

Ferric oxide Fe,03 0.0080 " 

Ferrous oxide FeO o . 007 2 " 

" sulphate FeSO, 0.0152 ." 

FeSOj,7H.0 0.027S " 

Iron (ferrous) Fe o . 005 6 ' ' 

No. 220. Decinorm.al Pot.vssium Permanoan.\te Solution. One cc. is equivalent to 

O.xalic acid H2C20,,2H,0 0.0063 gram, 

and to same weights for iron salts as given under N/io K,Cr,0,. 

* Use potassium chromate solution as an indicator, or add till precipitate appears. 

t Use a freshly prepared solution of potassium ferricyanide as an indicator, applying a drop of titrated solu- 
tion to a drop of indicator un a white surface. 



34 



FOOD INSPECTION AND ANALYSIS. 



The following table from Talbot * shows the reactions of the com- 
mon indicators used in acidimetr>': 



Indicator. 


Reaction with 
Acids. 


Reaction 

with 
Alkalies. 


Use with 

Carbonic 

Acid in Cold 

Solution. 


Use with 

Carbonic 

Acid in Hot 

Solution. 


Use with 

Ammonium 

::,alts. 


Use with 
Organic Acid. 


Litmus 


Red 

Pink 

Colorless 

Purple-red 

Purple-red 

Yellow 

Yellow 


Blue 
Yellow 
Pink 
Blue 
Blue 
Pink 
Red 


Unreliable 

Reliable 

Unreliable 

Unreliable 

Reliable 
Unreliable 
Unreliable 


ReUable 
Unreliable 
Reliable 
Reliable 
Reliable 
Reliable 
Reliable 


Reliable 
Reliable 

Unreliable 
Reliable 
Reliable 

Unreliable 
ReUable 


ReUable 


Methyl orange. . . 
Phenolphthalein. . 

Lacmoid 

Cochineal 

Rosolic acid 

Alizarine 


Unreliable 

Reliable 

Unreliable ( ?) 

Unreliable 

Unreliable! 

Reliable 



* Talbot, Quantitative Analysis, page 75. 
t ReUable with oxalic acid. 

REFERENCES ON LABORATORY EQUIPMENT, REAGENTS, ETC. 

Adriance, J. S. Laboratory Calculations. New York, 1897. 

Atkinson, E. Suggestions for the Establishment of Food Laboratories. U. S. Dept. 
of Agric, Off. of E.xp. Sta., Bui. 17. 

CoHN, A. J. Tests and Reagents, Chemical and Microscopical, known by their Authors' 
Names. New York, 1903. 

Kenwood, H. R. Public Health Laboratory Work. The Hygienic Laboratory. Phila- 
delphia, 1893. 

Krauch, C. Testing of Chemical Reagents for Purity. London, 1903. 

LuNGE, G., and Hurter, F. Alkali-maker's Handbook. London, 1891. 

Mayrhofer, J. Instrumente und Apparate zur Nahrungsmittel Untersuchung. 
Leipzig, 1894. 

Schneider, A. Reagents and Reactions known by the Names of their Authors. 1897. 

Sutton, F. Volumetric Analysis. 8th Ed. Philadelphia, 1900. 

Thorpe, T. E. Dictionary of Applied Chemistry. London, 1894. 



CHAPTER III. 

FOOD, ITS FUNCTIONS, PROXIMATE COMPONENTS, AND 
NUTRITIVE VALUE. 

Nature and General Composition. — Food is that which, when eaten, 
serves by digestion and absorption to support the functions and powers 
of the body, by building up the material necessary for its gro%\fth and 
by supplying its wastes. The raw materials that constitute our food- 
supply are not all available for nourishment, but often contain a propor- 
tion of inedible or refuse matter, which it is customary to remove before 
eating, such as the bones of fish and meat, the shells of clams and oysters, 
eggshells, the bran of cereals, and the skins, stones, and seeds of fruits 
and vegetables. The proximate components which make up the edible 
portion of food include in general water, fat, various nitrogenous bodies 
collectively known as protein, carbohydrates, organic acids, and mineral 
matter. Of these, water is hardly to be considered as a nutrient, though 
it plays an important part in nearly all foods as a diluent and solvent. 
The fat, protein, and carbohydrates all contribute in varying degree to 
the supply of fuel for the production of heat and energy. Besides this 
universal function, the fats and the carbohydrates serve especially to 
furnish fatty tissue in the body, while the protein is the chief source of 
muscular tissue. 

Liebig's classification of foods into nilrogcnous, or flesh formers, and 
non-nitrogeneous, or heat generators, is now no longer accepted as strictly 
logical, in view of the well-known fact that the nitrogenous materials, 
besides building up the body, aid in supplying the wastes and yielding 
energy, while the non-nitrogenous aid in furnishing tissue growth in 
addition to serving as fuel. Indeed protein is itself convertible into fats 
and carbohydrates within the body by peculiarly complex processes. 

The Fat of food.— Fats are the glycerides of the fatty acids, the 
characteristics of the various edible fats and oils being treated of under 

35 



36 FOOD INSPECTION AND ANALYSIS. 

their appropriate headings clsewlierc. Fat in human food is supphed 
by milk and its products, by the adipose tissue of meat, and in slight 
extent by the oil of cereals and by the edible table oils. The term ' ' ether 
extract" is sometimes used synonymously with fat, though other substances 
than fat are, when present, extracted by ether, such as chlorophyl and 
other coloring matters, lecithin, alkaloids, etc. 

Protein. — This term covers a wide variety of nitrogenous bodies, 
and in one form or another is found in nearly all foods, both animal and 
vegetable. The terms "proteids" and "albuminoids" are used generic- 
ally by some chemists as synonymous with "protein" to include all nitrog- 
enous bodies in food. The proteids and albuminoids strictly speaking 
are, however, subdivisions of the nitrogenous compounds, though in 
reality they are undoubtedly by far the most important from the stand- 
point of nutrition. 

Protein available for food is supphed chiefly by the flesh of meat and 
fish, by milk, cheese, and eggs, and to a smaller degree by the grains and 
vegetables, especially the legumes. 

Classification of Nitrogenous Bodies. — Nitrogenous compounds 

occurring in food are for convenience divided as follows: A. Proteids, 
B. Albuminoids, C. Amido-Compounds, D. Alkaloids, E. Nitrates, 
F. Ammonia, and G. Lecithin. The subdivision of the proteids and 
albuminoids as here given follows in the main the plan of Watts.* 

A. Proteids. — These are highly complex and usually amorphous 
compounds of carbon, hydrogen, nitrogen, oxygen, and sulphur, capable 
of conversion by certain enzymes and digestive juices through a process 
of hydration into proteoses and peptones. The latter after absorption 
in the body are reconverted into proteids. No marked distinction exists 
between animal and vegetable proteids. All proteids are insoluble in 
alcohol and in ether. Some are soluble in water and some are not. All 
are soluble in concentrated mineral acids and caustic alkalies by the aid 
of heat, but are decomposed thereby. All proteids are la-vo-rotar)' with 
polarized light. 

Qualitative Test for Proteids. — Xanthroproicic Reaction. — Concen- 
trated nitric acid added to a solution of a proteid may or may not form a 
precipitate. It, however, produces a yellow coloration on boiling. Addi- 
tion of ammonia in excess turns the precipitate or liquid yellow or orange. 

Millon's Reaction.— WiWon's reagent No. 184, page 28, when added to 

* Die. of Chem., \ol. H'., p. 330 et seq. 



FOOD, ITS FUNCTIONS, PROXIMATE COMPONENTS, ETC. .57 

a protciil solution produces a white pn.'ci[)itatc, which becomes brick-red 
on heating. Sodium chloride prevents the reaction. Various organic 
salts are precipitated by Millon's reagent, but the precipitate does not turn 
red on heating. 

Biuret Reaction. — If a solution of a proteid in dilute sulphuric acid be 
made alkaline with potassium or sodium hydroxide and very dilute copper 
sulphate be added, a reddish to violet coloration is produced, similar to 
that formed if biuret* be treated in the same way; hence the name. An 
excess of copper sulphate should be avoided lest its color obscure that o£ 
the reaction. 

Piotrowski's Reaction. — Dilute copper sulphate added to a moderately 
strong solution of a proteid forms a precipitate of albuminate of copper. 

Phosphotungstic Acid Reaction. — According to Stutzcr, all proteid 
matters in aqueous, alkaline, or acid solution are precipitated by saturation 
with a strongly acid solution of sodium phosphotungstate. For use as a 
reagent, dissolve the latter in sulphuric, acetic, or phosphoric acid. 

(a) Albumins. — These bodies are soluble in cold water and in satu- 
rated solutions of sodium chloride. They are precipitated by saturating 
with ammonium sulphate, and coagulated by heat. 

Occurrence. — In Animal Foods: Eggs, milk. 

In Vegetable Foods: Wheat, r}'e, and potatoes. 

Qualitative Tests. — All the general tests for proteids apply to albumins. 

Coagulation. — Animal albumins usually coagulate at about 75°; vege- 
table albumins at about 65°. 

Miscellaneous Reactions. — Dilute acids precipitate albumin with the 
aid of heat. Nitrate of mercurj' (in dilute nitric acid) precipitates albumins 
from their solutions; also Mayer's solution acidified with acetic acid. 

(b) Globulins. — These bodies are insoluble in water, soluble in 
dilute saline solutions, but insoluble in concentrated solutions of sodium 
chloride and magnesium or ammonium sulphate. They are coagulated 
by heat. 

Occurrence. — In Animal Foods: As myosin in muscle of meat; as 
vitellin in yolk of egg. 

In Vegetable Foods: As vegetable vitellin in cereals and legumes. 
Qualitative Tests. — Globulins are precipitated from their solution with 



* Biuret is the substance formed by heating urea to 160° according to the following 
reaction : 

2CON2H, = CjOjNjHs -t- NH3 

Urea Biuret Ammonia 



38 • FOOD INSPECTION AND ANALYSIS. 

saturated magnesium sulphate or sodium chloride. Albumins are not 
thus precipitated. 

(c) Albuminates. — These arc compounds formed by the action of 
weak acids and alkalies on globulins or albumins. They are insoluble in 
water and in natural solutions containing no salt, but soluble in acids and 
alkalies. They are not coagulated by heat. 

Occurrence. — In Animal Foods: Casein of milk. 

In Vegetable Foods: As legumin in peas and beans; as congluten in 
almonds. 

Qualitative Tests. — Albuminates like globulins are precipitated by 
saturation with neutral salts. 

If sulphuric acid is added to a solution of an albuminate in excess of 
acetic acid, a violet coloration and a slight fluorescence are produced. 

(d) Proteoses. — These are bodies formed from proteids by the action 
of proteolytic ferments, being intermediate products in the hydration of the 
proteids to peptones. They might be considered as semi-digested pro- 
teids. They may be artificially formed by heating various proteids with 
water, mineral acids, or steam. They are not coagulated by heat, and are 
insoluble in alcohol. 

Occurrence. — In Animal Foods: In sour milk and ripened cheese, as 
caseose. 

In Vegetable Foods: In wheat flour, as abrus. 

Subdivision of the Proteoses. — According to the proteids from which 
they are derived the proteoses are subdivided into alhumose, from albu- 
min, globulose, from globulin, vitellose, from vitellin, caseose, from casein, 
etc. 

Three varieties of albumose are as follows: proto-albumose, soluble in 
water (both cold and hot) and in dilute salt solutions, but precipitated by 
saturation with salt; helero-albiimose, insoluble in water, and deutero-albn- 
mose, soluble in water, but not precipitated by saturation with salt. 

Vegetable proteoses are sometimes called phyt-albumoses. 

Qualitative Tests. — Besides responding to the biuret reaction (p. 37) all 
proteoses are precipitated by nitric acid, the precipitate being soluble on 
heating, but reappearing when cold. 

Proto-albumose is precipitated from its solution by mercuric chloriJe 
and copper sulphate; hetero-albumose is precipitated by mercuric chlo- 
ride, but not by copper sulphate. 

(e) Peptones. — These bodies are the end products in the digestion 
or hydration of the proteids, of which the proteoses are intermediate. They 



FOOD. ITS FUNCTIONS, PROXIMATE COMPONENTS, FTC 



39 



arc soluble in water, insoluble in alcohol, not coagulated by heat, and not 
precipitated by nitric acid. 

Hemi- peptones are those which are capable of being further decom- 
posed into simpler bodies, such as leucine and tyrosine, by prolonged action 
of pancreatic juice. 

Anti- peptones are those incapable of further decomposition and which 
do not respond to Millon's reaction. 

Occurrence. — Both forms of peptones, being diffusible in animal mem- 
branes, are found in meat, but are not present in milk. They are not 
found in plants. 

Qualitative Tests. — Besides giving the biuret reaction, peptones are 
precipitated from their solution by tannic acid, picric acid, phosphomolyb- 
dic acid, and by sodium phosphotungstate acidified by acetic, phosphoric, 
or sulphuric acid. 

Peptones are the only soluble proteids not precipitated by saturation 
with ammonium sulphate. The following table is due to Halliburton:* 



Variety 

of 
Proteid. 



Proto- 
albumose 



Hetero- 

albumose 



Deutero- 
albumose 



Peptone 



Hot and 
Cold Water. 



Soluble 



Insoluble; i.e. 
precipitated 
by dialysis 
from saline 
solutions 



Soluble 



Soluble 



Hot and 

Cold Saline 

Solutions, 

e.g.. io% 

. NaCl. 



Soluble 



Soluble; part- 
ly precipita- 
ted, but not 
c o a g ulated 
on heating 
to 65° C, 

Soluble 



Soluble 



Satura- 
tion with 
NaCl or 
MgS04. 



Precipi- 
tated 



Precipi- 
tated 



Not pre- 
cipitated 



Not pre- 
cipitated 



Satura- 
tion with 
(NH^)2S04 



Precipi- 
tated 



Precipi- 
tated 



Precipi- 
tated 



Not pre- 
cipitated 



Nitric Acid. 


Copper 
Sulphate. 


Precipitated 
in cold: pre- 
cipitate dis- 
solves with 
heat and re- 


Precipi- 
tated 


appears on 
cooling 




Ditto 


Precipi- 
tated 


This reaction 
occurs only 
in presence 
of excess of 
salt 


Not pre- 
cipitated 


Not pre- 
cipitated 


Not pre- 
cipitated 



Copper 

Sulphate 

and Caustic 

Potash. 



Rose-red 
color (biu- 
ret reac- 
tion) 



Ditto 



Ditto 



Ditto 



(f) Insoluble proteids. — These are insoluble in water and dilute 
acids, but soluble with heating in strong mineral acids. The proteids of 
this class most commonly met with are fibrin and myosin in animal foods, 
and gluten in wheat. 

B. Albuminoids. — The albuminoids constitute a class of nitrogenous 
bodies closely allied to and in many respects resembling the proteids, 
including the following products found in animal foods: 
* Chemical Physiology and Pathology, page 131. 



4° FOOD INSPECTION AND ANALYSIS 

(a) Collagen, composing the fibers of connective tissue, is prepared 
from finely divided tendon by first soaking out the soluble proteids with 
cold water, then removing the mucin by soaking in lime water, and finally 
washing with water and dilute acetic acid. By boiling with water or 
subjecting to steam under pressure collagen is converted into 

(b) Gelatin, which is prepared also from bones by boiling. Insoluble 
in cold, but soluble in hot water. When the hot water solution cools 
it forms a jelly, if one per cent or more of gelatin is present in the solution. 
By prolonged boiling the gelatinizing power is lost. Aqueous solutions 
of gelatin are strongly Itevo-rotarj'. 

Qualitative Tests. — Gelatin is precipitated from its solution by mer- 
curic chloride, picric acid, or tannic acid. It is readily distinguished 
from the proteids in that it is not precipitated from its solution by lead 
acetate, nor by most of the metallic salts that throw down the proteids. 

(c) Mucin. — This is the principal ingredient of the ground substance 
of connective tissues in meat, and is also the chief component of mucus. 
It is precipitated by lead acetate, but by no other metallic salt. It responds 
to the xanthoproteic and Millon's reactions. 

(d) Nuclein is the chief component of the nuclei of cells, and contains 
much phosphorus. It occurs in the yolk of eggs and in milk. It is 
also present in yeast and in tea leaves. 

(e) Chondrin. — This is obtained from cartilage by long boiling. It 
is a transparent, gelatin-like substance, and in aqueous solution is pre- 
cipitated by the same reagents that precipitate gelatin. 

(f) Elastin is the substance which forms the elastic fibers of connective 
tissue. It is very insoluble, and in fact no solvent is known which does 
not decompose it. It is digestible by both pepsin and tr^'psin. 

C. Amides, Amido-acids, and Allied Products. — Under this 
head are included products derived from acids or bases, the radicles of 
which replace one or more of the hydrogen atoms in ammonia. The most 
common bodies of this class occurring in food products are; 

(i) Cholin (C5H,5N02), found in the muscular tissue of cattle and 
in yolk of eggs, also in certain fungi. 

(2) Betaine (CjH.jNO,), found in certain mollusks, as, for instance, 
the mussel, in putrefying fish, and (in the vegetable kingdom) in beets 
and hops. It is formed by the oxidation of cholin. 

(3) Asparagin (C^HjN.Oj), found in the shoots of asparagus, lettuce, 
peas and beans, and in the root of the marshmallow. It may be crystal- 
lized out from the expressed juice of the asparagus shoots by evaporation, 



hOOO, ns FUNCTIONS, PROXIMATE COMPONENTS, ETC. 41 

aft(.T havint; removed the albumin l)y coagulation (Ijy boiling) and by 
filtration.* 

Asparagin when heated with alkalies forms ammonia, and with acids 
forms ammonium salts. Freshly ])re])arcd copper hydro.vide is dissolved 
by an aqueous solution of asparagin by the aid of heat. If sections of 
vegetable tissues containing asparagin are placed in alcohol, crystals 
cf asparagin arc formed in such a manner as to be detected under the 
microscope. t 

Closely allied to the amides are the flesh bases of meat, chief among 
which are crcatin (C^H.NaOo), crcatimn (C^HyNsO), derived from crea- 
tin by the action of mineral acids and existing in some fish, carnin 
(CjHsN.Oj), and xanthin (CjH.N.O,). 

D. Alkaloidal Nitrogen. — Alkaloids do not naturally occur in 
foods, with the exception of tea, coffee, and kola-nuts, which contain 
caffeine, and cocoa, which contains theobromine. 

E. Nitrogen as Nitrates. — Foods in their natural condition rarely 
contain nitrates. bleats cured with saltpetre furnish the most common 
instance of nitrates in food. Nitrates are tested for by extracting the 
sample with water, and treating the extract with ferrous sulphate and 
sulphuric acid in the usual manner. 

F. Nitrogen as Ammonia. — Ammonia occurs very sparingly in 
food, unless the latter has undergone some form of decomposition. In 
ripened cheese and in sour milk one sometimes finds it in minute quan- 
tities. Its presence is tested for by distilling the finely divided sample in 
water free from ammonia, and testing the distillate with Nessler's reagent. 

G. Lecithin. — This substance fCj^HgoNPOg) is a phosphorized 
fat, and forms a part of the cell material in certain animal and vegetable 
foods. It is found in considerable quantity in the yolk of egg, and, in 
traces, in cereals, peas, and beans. It is a yellowish-white solid, soluble 
in ether and alcohol. Treated with water it swells up, forming an opales- 
cent solution or emulsion, from which it is precipitated by salts of the 
alkali metals. 

The Carbohydrates and their Classification. — The carbohy- 
drates supplied by food are milk sugar and the various sugars, starches, 
and gums from plant juices, cereals, fruits, and vegetables. Carbohy- 
drates are generally understood as being compounds of carbon, hydrogen, 
and oxygen, the last two elements being present in the proportion in 

* Zeits. fiir analytische Chemie, 22, page 325. 

t Wiley, Principles of Agric'l Analysis, Vol. III. p. 427. 



42 FOOD INSPECTION AND ANALYSIS. 

which they occur in water. They are divided into three main classes, as 
follows : 

A. The Glucose Group, or Monosaccharids (CjHijOj), including 
dextrose, levulose, and galactose. 

B. The Cane Sugar Group, or Disaccharids (CijHjjOu), including 
cane sugar, milk sugar, and maltose. 

C. The Cellulose Group (CeHioO;,), including starch, cellulose, dex- 
trin, gums, etc. 

Closely aUied to the carbohydrates, if not actually belonging to them, 
are inosite (CeH^Oe), occurring in muscular tissue, and peclose, found 
in green fruits and vegetables. 

The Organic Acids. — These acids are minor though important 
constituents of foods. From their conversion into carbonates within 
the body, they are useful in furnishing the proper degree of alkalinity 
to the blood and to the various other fluids, besides being of particular 
value as appetizers. They exist in foods both in the free state and as 
salts. Acetic acid is supplied by vinegar; lactic acid by milk, fresh meat, 
and beer; citric, malic, and tartaric acids by the fruits. 

MINERAL OR Inorganic Materials. — These substances occur in 
food in the form of chlorides, phosphates, and sulphates of sodium, potas- 
sium, calcium, magnesium, and iron, and are furnished by common salt, as 
well as by nearly all animal and vegetable foods. The inorganic salts are 
necessary to supply material for the teeth and bones, besides having an 
important place in the blood and in the cellular structure of the entire body. 

Fuel Value of Food. — In order to express the capacity of foods for 
yielding heat or energy to the body, the term fuel value is commonly used. 
By the fuel value of a food material is meant the amount of heat expressed 
in calories equivalent to the energy which we assume the body could obtain 
from a given weight of that food material, if all of its nutritents were 
thoroughly digested, a calorie being the amount of heat required to raise a 
kilogram of water i° C. This definition applies to what is known as the 
large calorie, which is one thousand times as large as the small calorie. 
Large calories are meant wherever the term occurs in this volume. The 
fuel value, or, as it is sometimes called, "heat of combustion," .may be 
determined experimentally with a calorimeter, or may be calculated by 
means of factors based on the result of many experiments showing the 
mean values for protein, fats, and carbohydrates. 

The Bomb Calorimeter.* — This apparatus in its most approved form, 

* U. S. Dept. of Agric, Off. of Exp. Sta., Bui. 21, pp. 120-126. 



FOOD, ITS FUNCTIONS, PKOXIM/ITE COMI'ONhNTS, ETC. 



43 



Fig. 13, consists of a waler-lighl, cylindrical, platinum lined, steel bomb, 
adapted to hold in a capsule the substance whose heat is to be determined, 
and containing also oxygen under pressure. This bomb is immersed in 
water contained in a metal cylinder, which is in turn placed inside of 
concentric cyhnders containing alternately air and water. The heat for 
igniting the substance is suppHed by the electric current passing through 
wires to the interior of the bomb and acting upon a cleverly devised 
mechanism therein. The heat developed by the ignition is measured by 




Fig. 13. — Bomb Calorimeter of Hempel and Atwater 

the rise in temperature of the water surrounding the bomb, as indicated 
by a very delicate thermometer graduated to hundredths of a degree, 
certain corrections being made, as, for instance, for the heat absorbed by 
the metal of the apparatus. A mechanical stirrer serves to equalize the 
temperature of the water surrounding the bomb. 

Calculation oj Fuel Value. — By reason of its great expense the calo- 
rimeter is beyond the reach of many laboratories, and on this account the 
expression of fuel values by calculation is the most common method em- 
ployed. For this the factors of Rubncr are generally used, in accordance 
with which the amount of energy in one gram of each of the three principal 



44 FOOD INSPECTION AND ANALYSIS. 

classes of nutrients are, for carbohydrates 4.1, for protein 4.1, and for fats 
9.3. Expressed in pounds, each pound of carbohydrate or protein has 
a fuel value of i860 calories, while each pound of fat has a fuel value of 
4220 calories. 

REFERENCES ON DIETETICS AND ECONOMY OF FOOD. 

Arusby, H. p. The Principles of Animal Nutrition. New York, 1903. 

Atwater, W. O. Dietaries in Public Institutions. Yearbook of U. S. Dept. of 

Agric, 1901, page 393. 
Food and Diet. Yearbook of U. S. Dept. of Agric, 1894, page 357. 

Principles of Nutrition and Nutritive Value of Food. Farmer's Bulletin, 142. 

Bellows, A. J. The Philosophy of Eating. Boston, 1867. 

BxiRNET, R. W. Foods and Dietaries. Phil., 1893. 

Bryant, A. P. Some Results of Dietary Studies in the United States. Yearbook of 

U. S. Dept. of Agric, 1898, page 439. 
Halliburton, W. D. Text-book of Chemical Physiology and Pathology. London, 

1891. 
Hammarsten, O. a Text-book of Physiological Chemistry. New York, 1898. 
Hutchinson, Robt. Food and the Principles of Dietetics. New York, 1901. 
Jaffa, M. E. The Study of Human Foods and Practical Dietetics. Cal. Exp. Sta., 

Bui. 110. 
Knight, J. Food and its Functions. London, 1895. 
Neumeister, a. Lehrbuch der physiologische Chemie. 1897. 
Pav\', T. W. a Treatise on Food and Dietetics. London, 1874. , 

Richards, E. H. The Cost of Living as Modified by Sanitarj- Science. New York, 

1900. 

The Cost of Food: A Study in Dietaries. New York, 1901. 

Simpson, H. Choice of Food. Manchester, England, 1889. Lectures. 
Strohmer, F. Die Emahrung des Menschen. 

Thompson, W. G. Practical Dietetics. New York, 1895. ■ 

Townshend, S. H. The Relation of Food to Health. St. Louis, 1897. 

Triie, a. C, and Milner, R. D. Development of Nutrition Investigations of the 

Dept. of Agric. Yearbook of U. S. Dept. of Agric, 1899, page 403. 
Stores Exp. St.4tion Annual Reports, 1888 et seq. 
Dietetic and Hygienic Gazette. 
Hygienische Rundschau. 
Zeitschrlft fur Physiologische Chemie, 1877 et seq. 

Also the following bulletins of the Office of Experiment Stations, U. S. Department 
of Agriculture. 
Bui. 21. Methods and Results of Investigations on the Chemistry and Economy of 

Food. By W. O. Atwater. Pp. 222. 
Bui. 28. (Revised edition.) The Chemical Composition of American Food Materials. 

By W. O. Atwater and A. P. Bryant. Pp. 87. 
Bui. 29. Dietary Studies at the University of Tennessee in 1895. By C. E. Wait, 

with comments by W. O. Atwater and C. D. Woods. Pp. 45. 



FOOD, ITS FUNCTIONS, PROXIMATE COMPONENTS. ETC. 45 

Bui. 31. Dietary Studies at tlic University of Missouri in 1895, and Data Relating 
to Bread and Meat Consumption in Missouri. By H. B. Gibson, S. Calvert, 
and D. W. May, with comments by W. O. Atwater and C. D. Woods. Pp. 24. 

Bu!. 32. Dietary Studies at Purdue University, Lafayette, Ind., in 1895. By W. E. 
Stone, with comments by W. O. Atwater and C. D. Woods. Pp. 28. 

Bui. 35. Food and Nutrition Investigations in New Jersey in 1895 and 1896. By 
E. B. Voorhees. Pp. 40. 

Bui. 37. Dietary Studies at the Maine State College in 1895. By W. H. Jordan. Pp. 

57- 
Bui. 38. Dietary Studies with Reference to the Food of the Negro in Alabama in 1895 

and 1896. Conducted with the cooperation of the Tuskegee Normal and 

Industrial Institute and the Agricultural and Mechanical College of Alabama. 

Reported by W. O. Atwater and C. D. Woods. Pp. 69. 
Bui. 40. Dietary Studies in New Mexico in 1895. By A. Goss. Pp. 23. 
Bui. 44. Report of Preliminary Investigations on the Metabolism of Nitrogen and 

Carbon in the Human Organism with a Respiration Calorimeter of Special 

Construction. By W. O. Atwater, C. D. Woods, and F. G. Benedict. Pp. 64. 
Bui. 45. A Digest of Metabolism Experiments in which the Balance of Income and 

Outgo was Determined. By W. O. Atwater and C. F. Langworthy. Pp. 434. 
Bui. 46. Dietary Studies in New York City in 1895 and 1896. By W. O. Atwater and 

C. D. Woods. Pp. 117. 
Bui. 52. Nutrition Investigations in Pittsburg, Pa., 1894-1896. By Isabel Bevier. 

" Pp. 48. 
Bui. 53. Nutrition Investigations at the University of Tennessee in 1896 and 1897. 

By C. E. Wait. Pp. 46. 
Bui. 54. Nutrition Investigations in Nevir Mexico in 1897. By A. Goss. Pp. 20. 
Bui. 55. Dietary Studies in Chicago in 1895 and 1896. Conducted with the coopera- 
tion of Jane Addams and Caroline L. Hunt, of Hull House. Reported by 

W. O. Atwater and A. P. Er>'ant. Pp. 76. 
Bui. 56. History and Present Status of Instruction in Cooking in the Public Schools 

of New York City. Reported by Mrs. Louise E. Hogan, with an introduction 

by A. C. True, Ph.D. Pp. 70. 
Bui. 63. Description of a New Respiration Calorimeter and Experiments on the 

Conservation of Energy in the Human Body. By W. O. Atwater and E. B. 

Rosa. Pp. 94. 
Bui. 68. A Description of Some Chinese Vegetable Food Materials and their Nutri- 
tive and Economic Value. By W. C. Blasdale. Pp. 48. 
Bui. 69. Experiments on the Metabolism of Matter and Energy in the Human Body. 

By W. O. Atwater and F. G. Benedict, with the cooperation of A. W. Smith 

and A. P. Bryant. Pp. 112. • 

Bui. 71. Dietary Studies of Negroes in Eastern Virginia in 1897 and 1898. By H. B. 

Frissell and Isabel Bevier. Pp. 45. 
Bui. 75. Dietary Studies of University Boat Crews. By W. O. Atwater and A. P. 

Bryant. Pp. 72. 
Bui. 84. Nutrition Investigations at the California Agricultural Experiment Station, 

1896-1898. By M. E. Jaffa. Pp. 39. 



46 FOOD INSPECTION AND ANALYSIS. 

Bui. 85. A Report of Investigations on the Digestibility and Nutritive Value of Bread. 

By C. D. Woods and L. H. Merrill. Pp. 51. 
Bui. 89. Experiments on the Effect of Muscular Work upon the Digestibility of Food 

and the Metabolism of Nitrogen. Conducted at the University of Tennessee, 

1897-1899. By C. E. Wait. Pp. 77. 
Bul. 91. Nutrition Investigations at the University of Illinois, North Dakota Agricul- 
tural College, and Lake Erie College, Ohio, 1896-igoo. By H. S. Grindley 

and J. L. Sammis, E. F. Ladd, and Isabel Bevier and Elizabeth C. Sprague. 

Pp. 42. 
Bui. 98. The Effect of Severe and Prolonged Muscular Work on Food Consumption, 

Digestion, and Metabolism, by W. O. Atwater and H. C. Sherman, and the 

Mechanical Work and Efficiency of Bicyclers, by R. C. Carpenter. Pp. 67. 
Bul. 107. Nutrition Investigations among Fruitarians and Chinese at the California 

Agricultural E.xperiment Station, 1899-1901. By M. E. Jaffa. Pp. 43. 
Bul. 109. E.xperiments on the Metabolism of Matter and Energy in the Human Body, 

1898-igoo. By W. O. Atwater and F. G. Benedict, with the cooperation of 

A. P. Bryant, A. W. Smith, and J. F. Snell. Pp. 147. 
Bul. 116. Dietary Studies in New York City in 1896 and 1897. By W. O. Atwater and 

A. P. Bryant. Pp. 83. 
Bul. 117. Experiments on the Effect of Muscular Work upon the Digestibility of Food 

and the Metabolism of Nitrogen. Conducted at the University of Tennessee, 

1899-1900. By C. E. Wait. Pp. 43. 
Bul. 121. Experiments on the Metabolism of Nitrogen, Sulphur, and Phosphorus in 

the Human Organism. By H. C. Sherman. Pp. 47. 



CHAPTER IV. 
GENERAL ANALYTICAL METHODS. 

Extent of a Proximate Chemical Analysis.^For purposes of studying 
the proximate composition of food for its dietetic value, it is nearly always 
necessary to make determinations of moisture, ash, fat, total nitrogen, and 
carbohydrates (when present), as well as of the fuel value. In some cases 
it may be desirable to proceed further, to make an analysis of the ash, for 
instance, to separate, at least into classes, the various nitrogenous bodies, 
especially in flesh foods, and perhaps to subdivide the starch, sugar, gums, 
and cellulose or crude fiber that make up the carbohydrates in the case of 
cereals. 

An analysis is considered complete whenever the purpose for which 
the examination has been made has been accomplished, and on that pur- 
pose depends solely the extent to which the various compounds present 
shall be subdivided and determined. Such a subdivision may be extended 
almost indefinitely. For example, a milk analysis may consist simply in 
the determination of the total solids and (by difference) the water. Again, 
it may be desirable to divide the milk solids into fat and solids not fat, 
and in some cases to carry the subdivision still farther and separate the 
solids not fat into casein, albumin, milk sugar, and ash. 

Determinations of one or more of the proximate components natural 
to food are frequently of great service in proving their purity or freedom 
from adulteration. For the latter purpose, especially in such foods as milk, 
vinegar, oils, and fats, the determination of specific gravity is also an 
important factor. Special methods of a peculiar nature are often neces- 
sary in the examination of particular foods, and such methods wU be 
treated subsequently under the appropriate headings. In the present 
chapter only such general methods as are applicable to a large variety of 
cases will be discussed. 

Expression of Results of a Proximate Analysis. — However complete the 
division of the various proximate compounds or classes of compounds 

47 



48 FOOD INSPECTION AND ANALYSIS. 

which the analyst sees fit to make, the results of his various determina- 
tions in a proximate analysis are expected to aggregate about ioo%. 
If every determination be directly made, the result will rarely be exactly 
loo, but the precision of the work is apt to be judged by its approach 
to lOO. 

It is often the custom to determine certain compounds or classes of 
compounds by difference. Thus in cereals the moisture, the proteids, the 
fat, and the ash may be determined by the regular analytical methods, 
and by subtracting their sum from loo the difference may be expressed as 
"nitrogen-free extract" or carbohydrates. It has long been customary 
in food analysis to calculate the protein by multiplying the total nitrogen 
by the factor 6.25, and on this basis analyses of thousands of animal and 
vegetable foods have been made. WTaile the figure thus obtained is an 
arbitrary one, being at best but a rough approximation of the amount of 
protein present, yet for many reasons there is much to commend this 
practice of reporting results. In the first place, in most cases it actually 
does approach the truth. Again, the nitiogenous ingredients of many foods 
are so numerous and varied, that for the every-day study of dietaries and food 
values it would be well-nigh impossible with our present knowledge to 
subdivide these compounds with any degree of accuracy, and especially 
with uniformity between different chemists, to say nothing of the time 
involved. 

From the fact that so many valuable analyses have already been 
expressed on the basis of NX6.25 for protein, the advantage of comparison 
with the results thus recorded would seem to be in itself a good reason 
for continuing the practice, especially until a factor that gives better 
average results can be adopted. By recording the actual nitrogen found 
as well as the "protein," old results may at any time be recalculated 
under new conditions, if found desirable. 

In flesh foods, when carbohydrates are known to be absent, the total 
protein may conveniently be determined by difference. Rather more 
progress has been made in the separation of the nitrogenous compounds 
of meats than of the vegetables and cereals, though the methods are by 
no means accurate or uniform. 

Most of the recorded analyses of vegetable foods express the carbohy- 
drates as a whole without attempting to subdivide them, at least further 
than possibly to express the crude fiber or cellulose separately. A much 
more intelligible idea of the dietetic value of these foods would be gained 
by a further separation into starch and sugars. 



CENER/tL /INALYTICAL METHODS. 49 

Preparation of the Sample. — It is at the outset of the utmost importance 
in all cases that a strictly representative portion of the food to be examined 
should be submitted to analysis. All refuse matter, such as bones, shells, 
bran, skins, etc., arc removed as completely as possible from the edible 
portion and discarded. 

If the composition of the entire mass cannot be made homogeneous 
throughout, it may be best to select from various portions in making up 
the sample for analysis, in order to represent as fair an average of the 
whole as possible. 

Finally the sample, if solid or semi-solid, should be divided as finely 
as possible, by chopping, shredding, pulping, grinding, or pulverizing 
according to its nature and consistency. 

For disintegrating such substances as vegetables and meats for analysis, 
the common household rotary chopping-machine is admirably adapted. 
For pulverizing cereals, tea, coffee, whole spices, and the like, the mortar 
and pestle may be used, or a rotary disk mill or spice-grinder. 

Specific Gravity or Density of Liquids. — Where formerly it was cus- 
tomary to compare the density of liquids with that of water at 4° C. (its 
maximum density) it is now more common to refer to water at 15.5° C. 
or 60° F., making the determination at that temperature. A common 
form of expressing the temperature of the determination and the tempera- 
ture of the standard volume of water with which that of the substance is 
to be compared, is the employment of a fraction, the numerator of which 
expresses the temperature of the determination and the denominator 

iS.5° iS-S° 100° 4° 

that of the standard volume of water, as -^q-, " " n ' 5' 'T, C.* 

4 15-5 15-5 4° 
When extreme accuracy in the determination of density is required, the 
pycnometer or Sprengel tube should be employed. 

The Hydrometer. — This instrument furnishes the most convenient and 
ready means of determining the density of liquids where extreme nicety 
is not required. If well made and carefully adjusted, the hydrometer 
may be depended on to three decimal places, but before relying on its 
accuracy, it should be tested by comparison with a standard instrument, 
or with the pycnometer. 

The liquid whose density is to be determined is contained in a jar 
whose inner diameter should be at least §" larger than that of the spindle- 

* Unless otherwise stated, all specific gravities in this volume are assumed to be expressed 

on the basis of -jij2- 
15-5° 



so FOOD INSPECTION ytND /tN /I LYSIS. 

bulb, and the temperature of the liquid should be exactly 15.5° when the 
reading is taken. 

For best results for use with liquids of varying densities, the laboratory 
should be furnished with a set of finely graduated hydrometers, each 
limited to a restricted part of the scale, together with a universal hydrom- 
eter coarsely graduated, covering the entire range, to show by preliminary 
test which of the special instruments should be used. 

A convenient set of seven such hydrometers are graduated as follows: 
0.700-0.850, 0.850-1.000, 1. 000-1.200, 1. 200-1. 400, 1. 400-1. 600, 1.600- 
1.800, 1.800-2.000, while the universal hydrometer has a scale extending 
from 0.700 to 2.000. Another less delicate set of three only has one for 
liquids lighter than water and two for heavier liquids. Some instruments 
have thermometers in the stem. Others require a separate thermometer. 

The Westphal Balance (Fig. 14). — This instrument consists of a 
scale-beam fulcrumed upon a bracket, which in turn is upheld by a sup- 
porting pillar. The scale-beam is graduated into ten equal divisions. 
From a hook on the outer end of the beam hangs a glass plummet pro- 
vided with a delicate thermometer, the beam being so adjusted that when 
the dry plummet hangs in the air, the beam is in exact equilibrium, i.e., 
perfectly horizontal as shown by the indicator on its inner end. If the 
large rider be placed on the same hook as the plummet and the latter 
immersed in distilled water. of the standard temperature at which the 
determinations are to be made (say 15.5° C), the scale-beam should 
again be in equilibrium if the instrument is accurately adjusted. As 
commonly made, the weight of the plummet including the platinum wire 
to which it is attached amounts to 15 grams, and the displacement of 
its volume to 5 grams of distilled water at 15.5° C, the normal temperature 
on which the determinations are based. Thus the unit (or largest) rider 
should weigh 5 grams, while the others weigh 0.5, 0.05, and 0.005 gram 
respectively. 

If, instead of distilled water, the plummet be immersed in the Hquid 
whose density is to be determined, the position of the riders on the scale- 
beam, when so placed as to bring the same into equihbrium, and when 
read in the order of their relative size (beginning at the largest), indicates 
directly the specific gravity to the fourth decimal place. 

If the liquid is lighter than water, the large rider is first placed in the 
notch where it comes closest to restoring the equihbrium of the beam, 
but with the plummet still underbalanced. The rider next in size is 
then applied in a similar manner, and, unless equilibrium' is exactly re- 



GESER/IL ANALYTIC/IL METHODS. 



5' 



Stored, the third and the fourth riders successively. If it happens that 
two riders should occupy the same position on the beam, the smaller 
is suspended from the larger. 

If the liquid is heavier than water, the method employed is the same 
except that one of the largest or unit riders is in this case always hung 
from the hook which supports the plummet, while the others cross the 




Fig. 14. — The Westphal Balance. 

beam at the proper points. If carefully made and adjusted, the Westphal 
balance is capable of considerable accuracy. 

A delicate analytical balance can be used in place of the less carefully 
adjusted Westphal instrument, by hanging the Westphal plummet from 
one of the scale-hooks of the same, and employing a fixed support for the 
glass jar that holds the liquid in which the plummet is to be immersed. 
The support is so arranged that the scale-pan below it can move freely 
without coming in contact with it. This arrangement is shown in Fig. 15. 

The Pycnometer, or Sped fie- gravity Bottle. — Fig. 16 shows the two 



52 



FOOD INSPECTION AND ANALYSIS. 



forms of pycnometer commonly made. The plain form has a ground- 
glass stopper with a capillary passage through it, the other has a fine ther- 
mometer connected with the stopper and a capillary side tube provided 
with a ground hollow cap. Both are made in different sizes to hold 
respectively lo, 25, 50 and 100 grams of distilled water at the standard 




Fig. 15. — The Analytical Balance Arranged for Determining Specific Gravity with the 

Westphal Plummet. 

temperature. It is convenient to have a counterweight for each pjcnom- 
eter as fitted with its stopper, thus avoiding much trouble in calculation. 
The calculation of results is simplified also if the pycnometers are accurately 
constructed to contain exactly the weight of distilled water which they 
purport to contain at the standard temperature, but it is rather difficult to 
procure such instruments, especially of the form furnished with the ther- 
mometer. Most instruments hold approximately the amount specified, 
the exact net weight of distilled water which they hold at standard tem- 
perature being found by careful test and kept on record. In determining 
the density of a liquid, the pycnometer is carefully filled with it at a tem- 
perature below the standard, the stopper carefully inserted, and the bottle 
wiped dr>'. Care should be taken that the liquid completely fills the bottle 
and is free from air-bubbles. The net weight of the liquid is then taken 



GENERAL /INALYTICAL METHODS. 



53 



on the balance, when the temperature has reached the standard (say 15.5° 
C), being careful to wipe olT the excess of liquid that exudes from the capil- 
lary due to expansion. The net weight of the liquid is divided by that of 
the same volume of distilled water, previously ascertained under the same 
conditions at the same temperature, the result being the density of the 
liquid. 

The pycnometer with thermometer attachment is obviously susceptible 
of a greater degree of accuracy than the other form, since the temperature 
of the liquid, even though 15.5° C. at the start, soon rises. 




Fig. 16. — Types of Pycnometer. 

The writer prefers to use the pycnometer provided with the ther- 
mometer, but without the hollow cap that covers the capillary side tube, 
unless liquids like strong acids are to be operated on, that might other- 
wise injure the balance. By keeping the liquid to be tested for some time 
in a refrigerator, it acquires a temperature of from 10 to 12° C. It is 
then transferred in the regular manner to the jn'cnometer and the ther- 
mometer-stopper inserted (but not the hollow cap) and the bottle wiped 
dry. There is ample time to adjust the balance-weights with extreme 
care while the temperature of the liquid is rising, leisurely wiping otT 



54 



FOOD INSPECTION AND ANALYSIS. 



at intervals with a soft towel the excess that exudes from the capillary 
tube, the final weight of the dn' bottle and contents being made at the 
exact temperature of 15.5° C. 

In taking the tare or adjusting the counterweight of a specific-gravity 
bottle, the latter should be perfectly clean and dry. It had best be rinsed 
first with water, then with alcohol, and finally with ether, all traces of the 
latter being removed by a current of dry air, or otherwise, before weighing. 
In making successive determinations of density of a number of different 
liquids with the same pycnometer, it is sufficient to rinse the bottle once 
with a little of the liquid to be tested before making each determination, 
when the various liquids are misciblc. When the liquids are immiscible, 
the bottle should be carefully cleaned in the manner described in the 
previous paragraph before making each test. 

The Sprengcl Tube. — The Sprengel tube is a variety of pycnometer 
useful when only a small quantity of the liquid to be tested is available. 
It is susceptible of great accuracy. It consists of a 
U-shaped tube (Fig. 17), each branch of which termi- 
nates in a horizontal capillary tube bent outward. 
One of the capillaries, h, has a mark ni thereon and 
has an inner diameter of about 0.5 mm. The 
diameter of the other capillary, a, should not exceed 
0.25 mm. The liquid at room temperature is as- 
pirated into the tube so as to fill it completely, the 
end h being dipped in the liquid while suction is 
apphed at the end a. The tube is then placed in a 
beaker of water kept at the standard temperature, 
the beaker being of such size that the capillary 
ends rest on the edge. The temperature of the 
hquid in the tube may be assumed to be constant 
Fig. 17.— Sprengel Tube when there is no further movement due to contrac- 
tor Determining Spe- tion in the larger capillary end, h. The meniscus of 
cific Gravity. ^^^ liquid, when cooled, should not be inside the 

mark m, and is brought exactly to the mark by applying a piece of bibulous 
paper to the other end, a. If a drop or two of liquid has to be added, this 
may be done by applying to the end a a glass rod dipped in the liquid. 
When exactly adjusted, the whole is wiped dry and quickly weighed, 
hung from the arm of the analytical balance. To avoid evaporation by 
contact with the air, the ends of the capillaries are sometimes ground 
to receive hollow glass caps not shown in the figure. 




GENERAL ANALYTICAL METHODS. 55 

Determination of Moisture. — The moisture is usually calculated 
from the weight of dry residue left after driving out all the water by evapo- 
ration from a weighed portion of the sample, using generally from i to lo 
grams in a tared dish. Some substances readily part with their water 
at 100°; others, again, require a much higher temperature or an extremely 
long heating. In general the highest possible degree of heat should be 
employed that will not affect the other constituents. Certain saccharine 
products should theoretically be dried at a temperature not exceeding 
70° on account of the dehydration of some of the sugars at higher tempera- 
tures. On the contrary, where readily decomposable organic matter 
is known to be absent and the character of the substance will permit, 
it is sometimes possible to employ temperatures considerably above 100° 
for quick drying. 

It is not always safe to assume that water is the only substance evap- 
orated on drying. Thus spices and other products containing essential 
oils give off appreciable quantities of these oils when dried at 100°. 

As it is rarely possible to attain a temperature higher than 98° in the 
water-oven, a gas-heated air-oven of the general type of that described 
on page 21, with ready means for controlling the temperature, is best 
for general moisture determinations in the food laboratory. 

Platinum dishes like those described on page 97 are admirable for 
nearly all moisture determinations, but thin dishes of porcelain, glass, or 
metal may be used. Thin Hcjuids and air-dr}-, powdered substances may 
usually be weighed directly in the dish and dried, without the use of an 
absorbent. 

With very moist substances containing much cellulose as well as water, 
it is often advantageous to weigh into the dish and allow to simmer for 
a long time on the water-bath, before drying to constant weight in the 
air-oven at higher temperature. 

Viscous substances should generally be spread over finely divided 
asbestos fiber, or pieces of pumice stone, or sea sand, which should be 
previously ignited and weighed with the dish, the object being to divide 
up the weighed portion as finely as possible for its better exposure to 
the heated air in the drying-oven. 

Determination of Ash. — For determining the percentage of the ash 
or mineral matter, it is often convenient to use the portion previously 
weighed out and dried in obtaining the moisture, the dry residue after 
the second weighing being in such cases burnt in the original dish over 
a low flame. Or, if desired, a fresh portion of the original substance may 



5 6 FOOD INSPECTION AND ANALYSIS. 

be air-dried or subjected to a preliminary drying in the water-bath and 
then burnt, taking care that there is no loss by sputtering or otherwise. 

Platinum dishes will be found much the most convenient in all cases 
where they may be safely used. In general the shallow flat dishes de- 
scribed on page 97 are preferable. Where lead or tin compounds are 
present, or when sulphides, sulphates, or phosphates are to be burnt with 
reducing agents, platinum is sure to be attacked and porcelain dishes 
or crucibles should be used instead. For the ordinary care of platinum 
dishes it would be well to know that platinum is attacked at ordinary 
temperatures by free chlorine and bromine, and, when ignited, by free 
sulphur, phosphorus, arsenic, and iodine. Platinum dishes are liable 
to injury also when used for the ignition of sulphates, sulphides, and phos- 
phates with reducing substances, or with metals present that are reduced 
in fusion, such as mercury, bismuth, tin, lead, zinc, antimony, etc. 

The degree of heat employed in ashing should be the lowest possible 
to insure complete oxidation of the carbon, so as to avoid driving off 
certain volatile salts that are sometimes present and that would be lost if 
the heat were too high. In general a dull red heat is preferable, the ash 
being usually best obtained by the direct action of the gas flame on the 
open dish containing the sample, the dish being suspended on a triangle 
or other support above the flame. It is rarely necessary to employ the 
muiiflc in obtaining the ash of food products. There are some substances, 
however, that would injure a platinum dish if ignited over the free flame 
which may be ashed with safety in a muffle. Thus the cereals like whole 
wheat and barley have been found to ruin platinum dishes when ignited 
therein directly over the flame, doubtless due to the phosphates present, 
but they may safely be ignited in platinum in the mufHe. Heating should 
be continued till the carbon is all oxidized, which is in most cases indicated 
by a white ash. It is, however, sometimes impossible to obtain a per- 
fectly white ash, but the appearance of the ash usually indicates when 
all the carbon has been burnt off. It is sometimes necessary to stir the 
contents of the dish with a stiff platinum wire from time to time during 
the ignition, the wire being weighed in with the dish. 

After ignition the dish is cooled in the desiccator before weighing. 

If an e.xamination of the ash for special ingredients is required, it 
is often necessary to burn a large portion of the sample. In this case 
it may be desirable to hasten the ignition by the careful use of ammonium 
nitrate as an oxidizing agent, or, in very refractory cases, as when sugar 
is present, it is well before igniting to saturate the sample with concen- 



GENERAL AN/1LYTICAL METHODS. 



57 



trated sulphuric acid, when the presence of sulphates in the ash is not 
objectionable. 

Methods for the detection and determination of the various ash ingre- 
dients are in general the familiar processes of the analytical chemist and 
will not be here considered. Such cases, however, as are peculiar to 
certain foods, like the metallic impurities that occur in canned, bottled, 
and preserved foods under certain conditions, 
will be considered in their appropriate place. 

Extraction with Volatile Solvents. — Wher- 
ever it is necessary to e.xhaust a substance of its 
ether-soluble or alcohol-soluble- ingredients, 
some form of continuous extraction apparatus 
is employed with advantage. 

The Soxhlet Extractor. — This apparatus, 
or one of its modifications is most commonly 
employed for continuous extraction. Fig. i8 
shows the simplest form of the Soxhlet ex- 
tractor, consisting essentially of a wide tube, 
A, provided with the side siphon a, a con- 
denser, B, and a wide-mouthed flask, C, all 
connected together in the manner illustrated, 
either by soft, accurately fitting corks or by 
ground joints, or by mercury-sealed connec- 
tions. Care in either case should be taken 
to have the joints perfectly tight, so as to 
avoid loss by leakage. The construction is 
such that the substance to be extracted, which 
is contained in the tube A, is subjected to 
successive treatment with freshly distilled 
portions of the solvent. The vapor from the 
solvent, boiling in the flask C, passes up 
through the side tube a' into the cold con- 
denser B, where it is again reduced to liquid •^'°- i^.— The Soxhlet Extractor 

, ^ 11 , , , ^1 , , , with Electric Heater. 

and lails drop by drop upon the suostance to be 

extracted, which is confined in a suitable porous receptacle or perforated 
vessel in the tube A. The substance is thus allowed to macerate in the 
solvent till the level of the latter reaches the top of the siphon, when 
all of the solvent in the tube drains ofi' into the flask C, carrying with it 
whatever it dissolves. The operation is at once repeated, the substance 




S8 FOOD INSPECTION AND ANALYSIS. 

being subjected to successive extractions with freshly distilled portions 
of the solvent, which leaves behind in the flask C whatever it dissolves. 
This operation of continuous extraction, when the conditions are right, 
goes on indefinitely without attention. 

The weighed portion of the sample to be extracted (from 2 to 5 grams) 
is first deprived of its moisture by drying, if free from volatile oil, and 
then transferred to the bottom of the tube A. There are various methods 
of doing this. If the substance is a fluid or semi-fluid like milk, it may 
be taken up on an absorption-coil of fat-free filter-paper and dried (see 
page 99), the dried coil being transferred to the tube A. Or the sample 
may be weighed into a verj' thin glass shell (Hoffmeister's Schalchen) 
in which it is dried, after which the shell is wrapped in bibulous paper, 
crushed between the fingers into small bits, and the whole, in the form 
of a small packet, is placed in the tube A. Or, again, the material, if 
in the form of an air-dried powder, may be weighed in a tared platinum 
dish or watch-glass and transferred by a brush into a partly folded wrapper 
of filter-paper, the ends of which are afterwards closed in by folding to 
form a packet, which is first dried thoroughly in the oven and then placed 
in the tube A. The fat-free porous shells made by Schleicher & SchuU, 
in various sizes to fit the Soxhlet tubes, form convenient receptacles 
for the extraction of dry substances. The sample may in most cases 
be directly weighed into one of these shells after taking its tare, and the 
dr\'ing and extraction carried out at once. 

Extraction with Ether. — In taking the so-called ether extract, some- 
times reckoned as fat, the solvent employed is either ethyl ether or the 
cheaper petroleum ether. Whichever reagent is employed, certain 
precautions are necessary' for the purity of the reagent. If ethyl ether 
is used, it should be entirely freed from moisture and alcohol by first 
shaking with water to remove the larger portion of the alcohol, allowing 
it to stand for some time over dry calcium chloride, and then distilling 
over metallic sodium. The ether thus prepared should be kept till used 
with sodium in the container, the latter being somewhat loosely corked, 
to allow escape of the hydrogen formed. 

Petroleum ether is variously termed benzine, naphtha, or gasoUne. It 
should be low-boiUng, preferably between 35° and 50°, and it is always 
best to redistil it before using, in order to be sure it is free from residue. 
As to the choice of the two reagents for use in fat extraction, it may be 
said that ethyl ether is the solvent most used, but if a large number of 
determinations are to be made, the lower cost of petroleum ether is to 



GENERAL ANALYTICAL METHODS. 



59 



be considered. A convenient still for fractionating such substances 
as petroleum ether Is shown in Fig. 19. 




Fig. 19. — Fractionating-still, Arranged for Petroleum Ether. 
Method oj Conducting the Extraction. — The flask C, Fig. 18, is first 
thoroughly cleaned and dried and then weighed, after which enough of 



6o 



FOOD INSPECTION AND ANALYSIS. 



the solvent reagent is poured into it to last through the period of the ex- 
traction, and the parts of the apparatus are connected. 

The heater employed should be a water-bath, or, as shown in Fig. i8, 
an electric stove, which may be provided with a fractional rheostat for 
varying the amount of heat. 

The degree of ebullition is so regulated as to allow the solvent to saturate 
the sample and siphon over into the flask C from six to twelve times an 
hour, the extraction being continued from two to six hours, or until all 
the ether-soluble material has been removed. Care 
should be taken also that the rate of boiling and the 
rate of condensation are so regulated that no appre- 
ciable loss of reagent occurs during the extraction. 
A strong smell of ether perceptible at the top of the 
condenser indicates a loss. The solvent is recovered 
at the end of the extraction by disconnecting the 
weighing-flask at a time when nearly all of the solvent 
is in the part A and before it is ready to siphon over. 
The weighing-flask is then freed from all traces of 
the solvent by drj'ing first on the water-bath and then 
in the oven, after which it is cooled in the desiccator 
and weighed, the difference between this and the first 
weighing representing the weight of the fat or ether 
extract. 

Extraction with Immiscible Solvents. — It is fre- 
quently necessary to dissolve out a substance from a 
i j liquid by shaking it with an immiscible solvent, as, 
for example, in the extraction of certain preservatives 
from aqueous or acid solutions with ether, petroleum 
ether, or chloroform. This can be done by shaking 
in ordinary flasks, but is attended by some difficulty 
and loss on decantation. A separatory funnel of the 
'Former Se"arato""^ "^yP^ shown in Fig. 20 is almost indispensable for this 
Funnel. kind of extraction. The hquid and solvent are trans- 

ferred to the funnel, which is then stoppered and shaken. If the 
solvent is heavier than water, as in the case of chloroform, it is 
drawn off from beneath through the outlet-tube of the funnel, closing 
the tap when the Hne of demarkation between the two liquids reaches 
the tap. Or, if the solvent is the lighter, as in the case of ether, the aqueous 
liquid lying beneath is first drawn off and finally the solvent is poured 




Fig. 20. — .'\ Convenient 



GENER/li ANALYTICAL METHODS. 6 1 

out through the top. If troublesome emulsions form when shaken, they 
may frequently be broken up by adding an excess of the solvent and 
again very gently shaking, or by careful manipulation with a stirring-rod. 
If the solvent is ether, and an olistinate emulsion forms, it may frequently 
be broken by the addition of chloroform. Such a mixture of ether and 
chloroform sinks to the bottom and may be drawn off as in the case of 
chloroform alone. Ether or chloroform emulsions that refuse to 
yield to either of the above methods may often be broken by the aid of 
a centrifuge. 

Determination of Nitrogen by Moist Combustion. ^In thus determin- 
ing nitrogen, the organic matter is iirst decomposed by digestion with an 
o.xidizer, the carbon and hydrogen being driven off in gaseous form as 
carbon dioxide and water respectively, while the nitrogen is converted 
into an ammonium salt, from which free ammonia (NH,) is later liberated 
by making alkaline. The ammonia is then distilled into an acid solution 
of known value and calculated by titrating the excess of acid. 

The Kjeldahl process of moist combustion, invohing the use of mercur}' 
or mercuric oxide in oxidizing and of potassium sulphide in distilling, has 
been largely superseded by the simpler Gunning method, which is better 
adapted for general food work. 

The method as described in its simplest form is not applicable in the 
presence of nitrates, but the latter occur ver)- rarely in foods in appreciable 
amounts. The ordinary Gunning method is not well adapted to the 
determination of nitrogen in pepper, on account of the difficulty with 
which piperin undergoes decomposition. In this case nitrogen is best 
determined by the Gunning-Arnold method, page 334. 

The Gunning Method. — Reagents: 

Standard alkali solution, N/io NaOH. 
Pulverized potassium sulphate. 
Sulphuric acid, concentrated. 
Sodium hydroxide, saturated solution. 
Standard acid solution, N/io HjSO^ or HCl. 
An indicator, cochineal. 
Granulated zinc. 

The digestion and distillation arc preferably carried out in the same 
flask, which should be pear-shaped with round bottom and made of hard, 
moderately thick, well-annealed glass. A convenient size has the follow- 
ing dimensions: length 29 cm., maximum diameter 10 cm.., tapering gradu- 



62 FOOD INSPECTION AND ANALYSIS. 

ally to a long neck, which near the end is 28 mm. in diameter with a 
flaring edge. Its capacity is about 550 cc. 

If desired, the digestion may be conducted in a smaller hard-glass 
flask of about 250 cc. capacity and of the same shape as the above, 
and the distillation in an ordinary round-bottomed flask of 500 cc. 
capacity. 

Introduce from 0.5 to 3.5 grams of the sample into the digestion-flask 
with 10 grams of potassium sulphate and from 15 to 25 cc. of concentrated 
sulphuric acid. The flask is inclined over the flame and heated gently 
for a few minutes Tjelow the boiling-point of the acid till the frothing 
has ceased, after whicli the heat is gradually increased till the acid boils, 
and the boiling is continued till the contents have become practically 
colorless or at least of a pale straw color. Wire gauze is interposed 
between the flask and flame. A funnel placed in the neck of the flask 
acts as a return-flow condenser. 

The contents of the flask are then cooled, and, if the digestion has 
been conducted in the larger flask suitable also for distilling, as above 
recorrmiended, 200 cc. of water are added and sufficient strong sodium 
hydroxide to make the contents strongly alkaline, using phenolphthalein as 
an indicator. If a separate flask is used for the distillation, the contents 
of the digestion-flask are transferred thereto with the water and the alkali 
added. A few pieces of granulated zinc should also be introduced, which 
by the evolution of gas prevents bumping and the sucking back of the 
distillate. The flask is then well shaken and connected with the con- 
denser, the bottom of which is provided with an adapter, dipping below 
the surface of the standard hydrochloric or sulphuric acid, a measured 
quantity of which is contained in the receiving-flask. The distillation is 
then continued till all the ammonia has passed over into the acid, this 
part of the operation recjuiring from forty-five minutes to an hour and 
a half. As a rule the first 150 cc. of the distillate will contain all the 
ammonia. 

The excess of acid in the receiving-flask is then titrated with standard 
alkali, and the amount of nitrogen absorbed as ammonia is calculated. The 
reagents, unless known to be absolutely pure and free from nitrates and 
ammonium salts, should be tested by conducting a blank experiment with 
sugar, by means of which any nitrates present are reduced. Any nitrogen 
due to impurities should be corrected for. 

The bank of stills used for Gunning and other distillations in the writer's 
laboratory is shown in Fig. 21. 



GENER/IL ztN/tLYTICAL METHODS. 



63 



Modification of Gunning Method to include Nitrogen of Nitrates. — In 

addition to the reagents used in the simpler Gunning method, sodium 
thiosulphate and sahcylic acid are required. 

A mixture of salicylic and sulphuric acids is made in the proportion of 
30 cc. of concentrated sulphuric to i gram of salicylic. From 30 to 35 cc. of 




Fig. 21. — Bank of Stills for Nitrogen Determination by Gunning Process. 

the mixture are added to the 0.5 to 3.5 grams of the substance in the di- 
gestion-flask, the flask is well shaken and allowed to stand a few minutes, 
occasionally shaking. Then 5 grams of sodium thiosulphate are added, 
and 10 grams of potassium sulphate, after which the heat is applied, at 
first very gently and afterwards increasing slowly till the frothing has ceased. 
The heating is then continued till the contents have been boiled practically 
colorless. From this point on, proceed as in the Gunning method. 



64 FOOD INSPECTION AND ANALYSIS. 

Determination of Free Ammonia. — A weighed quantity of the finely 
divided sample, treated with ammonia-free water and made alkaline with 
barium or magnesium carbonate, is distilled into a measured quantity of 
standard acid (tenlh-normal hydrochloric or sulphuric acid) and the amount 
of ammonia determined by titration. 

Determination of Amido-nitrogen.* — In the absence of ammonia, or 
after the removal of the ammonia as described in the preceding section, 
the sample is boiled for an hour with 5% hydrochloric or sulphuric acid, 
which converts the amido-compounds into ammonium salts (chloride or 
sulphate). Assuming asparagin to be the amido-compound acted upon, 
the reaction is as follows: 

2C,HsN,03+H,S0,+ 2H20 = (NH,),S0,+ 2C,H,N0,. 

Asparagin Ammonium Aspartic acid 

sulphate 

Exactly neutralize the free acid with sodium carbonate, add magnesia 
(free from carbonate), and distil into standard tenth-normal acid. The 
ammonia is determined by titration in the usual manner, and its nitrogen 
represents half of the nitrogen contained in the amido-compound, which 
it is customary to calculate as asparagin. 

Determination of the Various Carbohydrates. — L'ndcr title of " Cereals" 
in Chapter IX are given in detail methods for separation and determination 
of sugar, dextrin, crude fiber, etc. 

Poisoned Foods. — Such metallic impurities as are present in food 
products incidental to their preparation, or as adulterants, will be con- 
sidered under title of the foods hable to such adulteration. 

The detection of highly toxic substances in food, such as arsenic, mer- 
curic chloride, the alkaloids, and other organic poisons that do not occur in 
food naturally or accidentally, and are present, not as adulterants properly 
so called, but have been added with criminal intent to do injur}', come within 
the province of the medico-legal chemist or toxicologist rather than that 
of the food analyst, and are beyond the scope of the present work. The 
methods involved are similar to those used in the detection of these poisons 
in the stomach, viscera, and other organs and tissues. The reader is 
referred in this connection to such treatises as those of Blyth f and Dragen- 
dorf. I The analyst is, however, so often called upon to test foods for 
arsenic that an exception in this case will be made. 

* Wiley, Agricultural Analysis, Vol. III. p. 424. 

t Poisons their Effects and Detection. London, Griffen & Co., 1895. 

t Gerichtlich-chemische Ermittelung von Giften. St. Petersburg, 1876. 



GENERAL ANALYTICAL METHODS. 65 

Detection of Arsenic. — In tcsling most food substances for arsenic, it is 
usually unnecessary to entirely destroy the organic matter, but whenever 
possible the substance under examination should, by treatment with con- 
centrated nitric and sulphuric acids, be brought into the form of a dry 
char, which may readily be divided finely by the action of a pestle in a 
mortar. In this condition the arsenic, which by the process has been 
oxidized to arsenic acid, may be completely dissolved by continual treat- 
ment with boiling water. The hot-water solution containing the extract 
of the powdered char is then cooled, filtered, and submitted to the Marsh 
apparatus. 

For preliminary treatment of liquids or semi-liquid substances, proceed 
as directed under arsenic in beer, page 591. 

In treating substances like meats, vegetables, and the like, follow in 
general the directions of Chittenden and Donaldson * for organic tissues, 
the proportions of acid, etc., being varied to suit special conditions. Heat in 
a porcelain dish 100 grams of the finely divided substances with 23 cc. of 
pure concentrated nitric acid at a temperature between 150° and 160° C, 
stirring occasionally with a glass rod. After the substance has taken on 
a deep yellow or orange color, remove the dish from the heat, add 3 cc. 
of pure concentrated sulphuric acid, and stir while the nitrous fumes are 
given off. The operator should wear a rubber glove to protect the hands. 
Again heat to about 180° and add while hot, drop by drop, 8 cc. of pure 
concentrated nitric acid, stirring during the addition of the acid. Then 
heat at 200° till sulphuric acid fumes come off and a dry carbonaceous 
mass remains. 

This is then pulverized and exhausted with boiling water, and the 
aqueous solution, when cold, submitted to the Marsh test. 

The Marsh Apparatus and its Operation. — Fig. 22 shows a simple 
form of Marsh apparatus applicable for this work. The generator is 
provided with a doubly perforated rubber stopper, containing the usual 
deliver}'-tube and the entrance-tube. The latter has for convenience 
a 60° funnel at the top, into which the filter-paper can be folded and 
the solution containing the extract filtered directly into the generator. 
A chloride of calcium drying-tube is interposed between the generator 
and the capillary tube, the latter being drawn from hard arsenic-free 
tubing. 

The apparatus is operated in the usual manner, using arsenic-free 

* American Chem. Journal, II. No. 4; Chem. News, Jan. iSSi, p. 21. 



66 



FOOD INSPECTION /IND AN/t LYSIS. 



granulated zinc and dilute sulphuric acid. After running the current 
of hydrogen long enough through the heated tube to prove the absence 
of arsenic in the reagents or apparatus, the aqueous solution of the char 
is poured into the moistened filter at the top of the funnel-tube and allowed 
to filter slowly into the generator. The length of time necessary to deposit 
in the capillar}- tube all the arsenic in the sample, or to prove the absence 
of arsenic, varies with the conditions, but in general if no darkening of 




Fig. 22. — Maxsh .Apparatus for .\rsenic 

the tube occurs after an hour, the sample may be considered free from 
arsenic. 

Estimation of Arsenic* — With the aid of an assay balance sensitive 
to o.ooooi gram, it is possible to weigh with accuracy an arsenic mirror 
in a capillar}- tube when the metaUic arsenic amounts to o.ooci gram 
or more. Experience will soon show by the appearance of the mirror 
to the eye when that amount is exceeded. In this case the capillary- tube 
containing the mirror is cut off from the bulk of the tube, and, after drying 
in a desiccator, is weighed on the assay balance. The capiUarv" is then 
immersed in a solution of h\"pochlorite of sodium, which at once dissolves 
the arsenic only, if present, showing at the same time that the mirror is 
made up of arsenic and not antimony, which of course would not dissolve. 
The capillar}- is then washed, first by water by means of the wash- 
bottle, then vv-ith a few drops of alcohol, and is finally dried by heat. It 



* Leach, .\nnual Rep. Mass. State Board of Health, 1900, p. 700. .Analyst's Reprint, p. 83. 



GENERAL MNALYTICML METHODS. 67 

is then cfxjlcd and again weighed on the assay balance, the difference in 
weight corresjxjnding to the metaUic arsenic. 

If the amount of arsenic is small, it may be estimated by Sanger's 
mcthfK],* which consists in comparing the mirror in the capillary with 
a series of standard mirrors, made by using varying measured amounts 
of a standard arscnious oxide sfjiution. This sfjlution is prepared by 
dissolving i gram of pure arscnious oxide (AsjO,; in water with the aid of 
arsenic-free soflium carlxmate, and, after acidification with dilute sulj^huric 
acid, making up to a liter. Ten cc. of this sfjlution are measured out 
carefully and made up to a liter with water, the strength of the dilute 
sfilution Ixjing o.oi mgr. to i cc. One cc, 2 cc, 3 cc, etc., of this second 
or dilute sfjlution are separately measured into the .Marsh apparatus to 
give mirrors corresponding to the same number of hundredth-milligrams. 

r?:fere.\ce.s to general food a.valy.sis. 

Allf.v, a. II. Commerrial Organic Analysis. Philadelphia, 1898. 
Uattkrshall, J. P. VfxA Adulu-ralion antl its Detection. N'cw York, 1887. 
Hf.i.i,, Jas. The Analysis and .■\dullcrajion of Ffjod.s, I'ls. I and II. Lfjndon, 1881. 
Hi.YTil, .\. W. anfl .\I W. V<x;<h, their Comjxisition and Analysis. New York, 1903. 
BoHMER, C. Die Kraftfuttermittcl, ihre Rohstoffc, HcrsU-llung, Zusammensetzung, 

etc. Berlin, 1903. 
BujARD, A., and Baier, E. Ililfsbuch fUr Nahrungsmittcl Chemikcr. Berlin, 1894. 
BuRCKF.R, E. Traitc? des Falsifications ct Alterations dcs .Substances alimentaircs et 

dcs Boissons. Paris, 1892, 
D1ETZ8CH, O. Die Wichtig.stcn Nahrungsmittel und Gctranke. Zurich, 1884. 
E^LSSKR, F. Praxis dcr Nahrung.smiltcl Chemiker. Ix-ipzig, 1880. 
Ephkaim, J. Originalarlxriten Ulx-r Analy.sc der .\ahnjng.smittel. Leipzig, 1894. 
GiRARi), C, et Dcpk6, \. Analyse des Matil-rcs alimentaircs et Recherche des leurs 

Falsifications. Pari.s, 1894. 
Hanausf.k, T. F. Die Nahrungs- und Gcnussmittcl aus dem Pflanzcnreiche. 1884. 
Hassau., a. H. Fo<kJ, its Adulterations and the Methofls for their Detection. London, 

1874. 
KdNic, J. Chemi.sche Zusammensetzung der mcnschlichen .Nahrungs- und Genus.s- 

mittel. Berlin, 1903. 
Leach, A. E. Ffx>d: MethofLs of Inspcrtion and .Analysis. Article in Rcfertnte 

IIandW)k of the Medical Sciences, Vol. 3, pages 180-183. 
Lepfma.s-.s-, II., and Bkam, \V. .Select .Methods of Vo(x\ .Analysis. Philadelphia, 1901. 
PoLiN et Labit. Examcn des Aliments suspects. Paris 1892. 
ROttcer, H. Kurzcs Lehrbuch der Nahrungsmitttl Chemie. Leipzig, 1903. 
Rupp, G. Die Untersuchung von Nahrung.smitteln, Genussmitteln und Gcbrauchs- 

gegenst^nden. 1900. 

*Proc. Acad, of Arts and Sciences, XXVI. (1891J p. 24. 



68 FOOD INSPECTION AND ANAL YSIS. 

Thoms, H., und Gilg, E. Einfiihrung in die praktische Nahrungsmittel-Chemie. 
Leipzig, 1899. 

ViLLiERS, A., et Collin, E. Traite des Alterations et Falsifications des Substances 
alimentaires. Paris, 1900. 

WiESSNER. Die Rohstoffe des Pflanzenreiches. Leipzig, 1900. 

Wiley, H. W. Principles and Practice of Agricultural Analysis. Vol. III. Agricul- 
tural Products. Chem. Pub. Co., Easton, Pa., 1897. 

The Analyst. London, 1877 et seq. 

Revue International des Falsifications. Amsterdam, 1888 et seq. 

Vierteljahresschrift der Chemie der Nahrungs- und Genussmittels. Berlin, 1884 et 

seq. (Discontinued 1897.) 
Zeitschrift fur Untersuchung der Nahrungs- und Genussmittel. 1898 et seq. 
Vereinbarungen zur Untersuchung und Beurtheilung von Nahrungs- und Genussmit- 

teln. Berlin, 1897. 
Also the following bulletins of the Bureau of Chemistry, U. S. Deptartment of 
Agricuhure: 

Bulletin 13, Parts i-io. Food and Food Adulterants. 1887-1902. 
Bulletin 46. Methods of Analysis adopted by the A. O. A. C. 1899. 
Bulletin 65. Provisional Methods for the Analysis of Foods, adopted by the A. O. A. C. 

Nov. 14-16, 1901. 1902. 



CHAPTER V. 
THE MICROSCOPE IN FOOD AxNALYSIS. 

Microscopical vs. Chemical Analysis. — A very important means of 
identification of adulterants in many classes of food products is furnished 
by tlie microscope, which in many cases affords more actual information 
as to the purity of food than can be obtained by a chemical analysis. 
This is especially true of coffee, cocoa, and the spices, wherein the micro- 
scope serves to reveal not only the nature of the adulterants, but also not 
infrequently the approximate amount of foreign matter present. In the 
case of the cereal and leguminous starches so commonly employed as 
adulterants, a microscopical examination is of paramount importance. 

The chemical constants of many of the adulterants of coffee and the 
spices do not always differ sufficiently from those of the pure foods in 
which they appear to be distinguished therefrom with accuracy and 
confidence by a chemical analysis alone. On the other hand, one who 
is famihar with the appearance under the microscope of the pure foods 
and of the starches and various ground substances used as adulterants, 
can, with certainty, identify very minute quantities of these materials, 
when present, with the same ease that one can recognize megascopically 
the most familiar objects about him. 

A chemical test may, for example, indicate the presence of starch, 
but it cannot reveal the particular kind of starch. The microscope will 
at once show whether the starch present is wheat or corn or potato or 
arrowroot, since these starches differ almost as much in microscopical 
appearance as do the physical characteristics of the grains or tubers from 
which they are obtained. Again, by a chemical analysis an abnormal 
amount of crude fiber may show the presence of a woody adulterant, 
but only the microscope will enable one to decide whether the impurity 
consists of sawdust or ground cocoanut shells. Not only in such in- 
stances as these is the microscopical examination of greater importance 

69 



70 . FOOD INSPECTION AND ANALYSIS. 

than a chemical analysis in establishing the purity of the food, buc it 
is at the same time a much cjuicker guide. 

The Technique of Food Microscopy. — The recognition of aduherants 
by the microscope is not difficult, and by no means involves the labor 
and skill necessary for almost all other kinds of histological work. In 
the examination of cocoa, coffee, tea, and the spices for adulteration, a 
careful study of the powdered substance in temporary water mounting 
will in most cases prove sufficient to familiarize the food analyst with 
their characteristics under the microscope, and it is not absolutely neces- 
sary' for him to familiarize himself with the details of section cutting, 
dissecting, or permanent mounting unless he so desires. The treatment 
in detail of these latter branches of vegetable histology is beyond the 
scope of the present work. For full information along these lines the 
reader is referred especially to such works as those of Behrens * and of 
Zimmerman,! together with the list of references on page 86. 

Standards for Comparison. — For standards the analyst should provide 
himself with as complete a set as possible of the various materials to be 
examined, taking care that their absolute purity is established. Where- 
cver possible, he should grind the sample himself from carefully selected 
whole goods. These, together with samples of the starches and other 
adulterants, all of known purity, should be contained in small vials care- 
fully stoppered and plainly labeled, arranged alphabetically or in some 
equally convenient manner in the desk or table on which the microscope 
is commonly used. The adulterants included in this set of standards 
should be not only those which experience has shown most liable to be 
emploj'ed, but any which, by reason of their character, might in the 
analyst's opinion be used under certain conditions. 

APPARATUS. 

The Microscope-stand. — An expensive or complicated stand is in- 
necessar)'. The prime requisites for good work in a microscope-stand are 
firmness or rigidity, and accuracy in centering. An inexpensive stand 
possessing these features can be used for the best work, providing the optical 
parts are satisfactory. It is well, if economy must be practiced, to purchase 
a simple stand provided with the society screw, and let the larger portion 
of the allowance go for a high grade of lenses, since many of the attach- 
ments inherent in a high-priced stand, though often of convenience, may 
well be dispensed with. 

* Guide to the Microscope in Botany. f Botanical Microtechnique. 



THE MICROSCOPE IN FOOD /IN A LYSIS. 



71 



A stand of the so-called continental type (having the horseshoe base) 
is preferable. A square stage is rather more convenient than the circular 
form, and the jointed pillar possesses advantages over the rigid variety 
in ease of manipulation that are certainly worth considering. 

The smooth working of both the coarse and fine adjustments should 
not be lost sight of. If the microscope is to be used exclusively for food 
worl^, a substage condenser is unnecessary, hence the construction of the 
substage may be very simple, unless bacteriological work is to be done as 




Fig. 23. — Continental Type of Microscope. 

well. The stand should be so constructed as to allow the analyst to readily 
bring into place the parts of a polarizing apparatus and as quickly to 
remove them. 

A nose-piece, while not indispensable, is a great convenience for the 
quick transfer of objectives. A double nose-piece carrjdng two objectives 
is ample for routine food work. 

The Optical Parts are by far the most important, and should be of 
superior quality, though not necessarily of the most expensive makers. 
The food analyst should have at least two objectives, one for high- and 
one for low-power work, and preferably two oculars. 

For the routine examination of powdered food substances the writer 
prefers a ^-inch objective, used with a medium ocular, the combination 



72 



FOOD INSPECTION AND ANALYSIS. 



giving a magnification of from 240 to 330 diameters, according to the 
ocular employed. For a low-power objective the |-inch is a convenient 
grade, which, in connection with a low-power eyepiece, is well adapted 
for the examination of butter and lard, and for use with the polariscope. 

The Micro-polariscope. — This accessory is useful in the identifica- 
tion of starches and other ingredients, and for ascertaining whether or 
not fats have been cr}^stallized. The most convenient form is that in 
whicli the polarizer is held below the stage, while the analyzer is applied 
above the objective, between it and the tube. This form permits the use 
of any desired ocular. 





L mill 

Fig. 24. — Polarizer cind .\nalyzer for the Microscope. 

A common form of construction is one in which the substage is adapted 
to carry interchangeably the diaphragm tube and the polarizer. If the 
polariscope is much used, it becomes desirable to provide means for quickly 
changing the polarizer and diaphragm tube below the stage, and for moving 
the analyzer in and out of place above the objective. Winton * has devised 
a microscope-stand with this in view, especially adapted to the needs of 
the food analyst. 

If the polariscope is to be used often, it is convenient to have within 
easy access two stands, one with the polariscope mounted in place in con- 
nection with low-power glasses ready for use, and the other stand pro- 
vided with the ordinary high- and low-power objectives only. 

Microscope Accessories include of necessity a large number of slides 
and cover- glasses. The latter are best of the square variety, f inch in 
size, and of medium thickness (No. 3). 

One or more dissect ing-necdles in holders and a small hand magni- 
fying-glass should also be provided. 



* Journal .\pp. Microscop)', 2, p. 550. 



THE MICROSCOPE IN FOOD /INADrSIS. 



73 



Other useful accessories arc a mechanical stage, a pair of tine tweezers, 
knives, scissors, and, if sections are to be cut, a plano-concave razor. 

Preparation of Vegetable Food Products for Microscopical Examina- 
tion. — The ground spices and cocoas of commerce are usually of the 
requisite fineness for direct examination without further treatment. Coffee, 
chocolate, starches, and similar products should be ground in a mortar 
fine enough to pass through a sieve with from 60 to 80 meshes to the inch. 

A small portion of the powdered sample is taken up on the tip of a 
clean, dry knife-blade, and placed on the microscope-slide. By means 
of a medicine-dropper a drop of distilled water is applied, and the wetted 



Fig. 




Mechanical Stage for Microscope. 



powder is then rubbed out under the cover-glass between the thumb and 
finger to the proper fineness. 

The water-mounted slide thus prepared, while useful only for tem- 
porary purposes, has proved to be best adapted to the analyst's require- 
ments for routine microscopical examination of powdered food products 
for adulteration, partly because water is the best medium in most cases 
for showing up the structural characteristics of these substances and their 
adulterants, and partly because it senses best for the "rubbing out" 
process between thumb and finger under the cover-glass, whereby the 
sample is brought to the requisite degree of fineness. 

Experience will soon show how far this rubbing out should be carried 
for the best effects. Gentle pressure should be applied, care being taken 
not to break the cover-glass, especially if the sample contain anything of 
a gritty nature. The rubbing should be continued till the coarser par- 



74 FOOD INSPECTION /tND ANALYSIS. 

tides and overlying masses are separated and distributed uniformly, but 
if too long persisted in, the forms of the tissues, starch grains, and other 
characteristic portions will be partially destroyed and of too fragmentary 
a nature to be readily recognizable. 

Canada Balsam is the best mountant for the examination of starches 
under polarized light. In this medium, under ordinary illumination, the 
starches are not plainly visible, since the refractive inde.x of the balsam 
is so near that of the starch grains themselves. With the crossed nicols, 
hovi^ever, the starch grains stand out very clearly and distinctly in a dark 
background. 

Specimens to be mounted in Canada balsam must be free from 
moisture. Dehydration is often resorted to by soaking the specimens in 
alcohol. Canada balsam in solution is prepared by dissolving the 
balsam broken into small pieces or powdered in a mortar in an equal 
volume of xylol, filtering and evaporating to sirupy consistency at room 
temperature. 

Glycerin Jelly* — This is the best permanent mountant for powdered 
food substances and is prepared as follows: i part by weight of the finest 
French gelatin is soaked two hours in 6 parts of distilled water, after which 
7 parts by weight of C. P. glycerin arc added, and to each loo parts cf 
the mixture add i part of concentrated carbohc acid. Heat the mixture 
while stirring till flocculency disappears and filter through asbestos while 
warm, the asbestos being previously washed and put into the funnel 
while wet. The jelly is solid at ordinarj' temperatures, and must be 
warmed to melt. A small bit of this jelly is removed from the mass by 
a knife-blade and placed on the cover-glass, which is held over a gas flame 
till the jelly is melted. The powdered specimen being then shaken into 
the molten drop, the cover-glass is gently placed upon it (being brought 
down obliquely to avoid formation of air-bubbles) and pressed down in 
place. 

Microscopical Diagnosis. — It is never safe to pass judgment on a 
spice or other food by the microscopical examination of a single portion. 
Several slides should be prepared with bits of the powder taken from 
different parts of the mass, before the character and extent of the adultera- 
tion can be safely determined. Care should be taken that the slide, the 
knife-blade, the water, and the medicine-dropper be perfectly clean and 
free from contamination with previous specimens. 

It should be borne in mind that at best a composite powdered sample 



* Botan. Centralbl., Bd. i, p. 25. 



THE MICROSCOPE IN FOOD ANALYSIS. 75 

is but a mechanical mixture of various tissues, and that no two portions 
will show exactly the same composition. 

Characteristic Features of Vegetable Foods under the Microscope. — 

The structural features of a powdered spice, examined itiicroscopically, 
will be found to differ considerably in appearance from those of a thin, 
carefully mounted section of the same spice. Instead of the beautiful 
arrangement of cells and cell contents with the perfect order of various 
parts as seen in the mounted section, one finds in the powdered sample 
under the microscope what often appears to be a most confusing mass 
of fragments of various tissues. For this reason the most striking charac- 
teristics seem to vary with different observers, and it is a well-known 
fact that microscopists differ widely as to conceptions of size, shape, and 
ordinary appearance, even in the case of certain of the well-known starch 
grains. It is on this account that, irrespective of the description of others, 
the analyst should familiarize himself with the microscopical appearance 
of the foods with which he is dealing, as well as of their adulterants, form- 
ing his own standards as to what constitute the recognizable features, 
from specimens prepared by himself. 

In the large variety of ground berries, buds, tubers, barks, etc., from 
which the spices and condiments are prepared, as well as in the grains, 
legumes, shells, fruit stones, and other materials forming the most familiar 
adulterants, the kinds of plant tissues and cell contents which, under 
the microscope, serve as distinguishing marks or guides for identification 
are comparatively few in number. 

The most common of these varieties of cell tissue and of cell contents 
to be met with by the food microscopist in his work are briefly the fallow- 
ing: 

Parenchyma. — This is most abundant and widely distributed, forming 
as it does the thin-walled, cellular tissue of nearly all vegetable food sub- 
stances. The walls of parenchyma cells are, as a rule, colorless and 
transparent. The forms of the cells are varied and are often sufficiently 
characteristic in themselves to identify the substance under examination. 

Sclcrcncliyma, or stone cells, are the thick-walled woody cells forming 
the hard part of nut shells, fruit stones, and seed coverings, occurring also 
in some fruits and barks. These cells are more often colored and of 
various shapes but almost always irregular, sometimes elongated, as in 
cocoanut shells and olive stones occasionally nearly rectangular, as in 
pepper shells, and sometimes polygonal or nearly circular. 

In appearance the sclcrenchyma cell commonly has a more or less 



76 



FOOD INSPECTION AND /IN /I LYSIS. 



deep, central or axial rift, from which small fissures extend through the 
thick walls, somewhat suggestive of the iris. See Fig. 27. 

Variously shaped sclerenchyma cells are found in allspice, cassia, 



H 



ito 



(fl 







nl 



nSPnui 




in' 



Fig. 26. — Typical Forms of Various Cell Tissues. Longitudinal section through a clove, 
showing: Pp, two forms of parenchyma; B, bast fibers; g, vascular and sieve 
tissue; KK', cells with calcium oxalate crystals. (After Vogl.) 

pepper, clove stems, nut shells, etc. Stone cells are optically active to 
polarized light, and between crossed nicols are very conspicuous by their 
bright appearance. 




Fig. 27. — Sclerenchyma, or Stone-cell Tissue. A cross-section through the stone-cell 
layer of the fruit shell of black pepper. (After Vogl.) 

Fibro-vascular Tissue is composed of elongated, lignified cells, gener- 
ally spindle-shaped. The most common varieties are the bast fibers. 



THE MICROSCOPE IN FOOD ANALYSIS. 



77 



occurring in the bark (or phloem), and the wood fibers, in the woody portion 
(or xylcm) of flowering plants. Bast fibers are common in cassia and 
ground bark, and wood fibers arc met with in ginger and turmeric and such 
adulterants as sawdust. 

Corky Tissue, or Suberin, constitutes the thin-walled, spongy cells form- 
ing the protective, outer dead layers of the bark. This is found in cassia, 
and in the barks used as adulterants. Suberin is tested for by potassium 
hydroxide (p. 8i). 

Spiral and Reticulated Ducts, and Sieve Tissues of various forms 
(suggested by the names), occur commonly interspersed among the paren- 
chyma and vascular tissue. Notable examples of them 
are the spiral ducts found in chicory. 

Starch wherever it occurs furnishes the most -charac- 
teristic feature of the cell contents, and, as a rule, will at 
once indicate under the microscope, by the shape and 
grouping of its granules, the particular substance of which 
it forms a part. It is very abundantly distributed through- 
out the vegetable kingdom and occurs in a wide variety of 
forms. It is particularly conspicuous when viewed by 
polarized light. Between crossed nicols such starches 
as com, potato, and arrowroot show out brightly from Fig. 28.- 
a dark background with dark crosses, the bars of which 
intersect at the hylum of each granule. When a selenite 
plate is introduced above the polarizer, a beautiful play of colors is 
seen with various starches, a phenomenon which Blyth ap5)lies as a 
means of identification and classification, but which more modern micro- 
scopists regard as of minor importance to distinguishing the various 
starches morphologically. Starch is found naturally in the cereals, legumes, 
and many vegetables, in cassia, allspice, nutmeg, pepper, ginger, cocoa, 
and turmeric. The cereal and leguminous starches from their inertness 
anid cheapness constitute the most common adulterants of the spices and 
of powdered foods in general. Starch grains are found in the cells of the 
parenchyma and in other cellular tissues. Iodine is the special reagent 
(p. 79)- 

Gums and Resins occur in characteristic forms among the cell contents 
of some of the spices. As an example, the portwine-colored lumps of gum 
in allspice furnish one of the most ready means of recognizing that spice 
microscopically. Resin is tested for microchemically with alkanna tincture 
(p. 80). 




-Reticula- 
ted Ducts of Chic- 
ory. (After \"ogl.) 



78 FOOD INSPECTION AND ANALYSIS. 

Aleurone, or Protein Grains, occur in some of the spices, but are not 
especially characteristic. They somewhat resemble small starch grains. 
Most varieties of protein grains are soluble in water, but some are insoluble. 
The soluble varieties, which are not apparent in water- mounted specimens^ 
must be examined in absolute alcohol, glycerin, or oil. In leguminous 
seeds aleurone occurs closely intermingled with starch in the same cells, 
while in the cereals it occupies the whole cell. 

Protein grains are tested for under the microscope by iodine in potas- 
sium iodide, which turns them brown or yellowish brown, and by Millon's 
reagent, which colors them brick red. 

Plant Crystals are not uncommon in the class of substances which 
the food analyst examines. The most common of these are the piperin 
crj'stals found in pepper. Needle-shaped calcium oxalate crystals, 
termed raphides, commonly grouped in bundles, are found occasionally 
in powdered cassia, and also in the onion and the beet. 

Crystals of calcium carbonate are sometimes met with also, as, for 
example, in hops. Calcium oxalate crystals are insoluble in acetic acid, 
while being readily soluble in dilute hydrochloric. Calcium carbonate 
crystals are soluble with effervescence in both acids. The acid reagents 
are directly applied to the sample in water-mount under the cover-glass, 
and the reaction observed through the microscope. 

Fat Globules are of common occurrence in many foods and appear of 
various sizes, sometimes large and conspicuous, and again almost lost 
sight of because of their minuteness. They are sometimes colorless, as in 
mace, and sometimes deeply tinted, as in cayenne. Alkanna tincture is 
used as a reagent for fat (p. 80). 

Other Cell Contents of less importance, but which may be identified by 
the microscope with reagents, are tannic acid (tested for by chloriodide 
of zinc and Tcrric acetate (pp. 79 and 80), and various essential oils, for the 
detection of which alkanna tincture is employed. 

REAGENTS IN FOOD MICROSCOPY. 

Unless a more extended microscopical investigation of vegetable food 
substances is contemplated than is involved in the mere identification of 
adulterants, the analyst will have little need for reagents,* but will depend 
almost entirely on the form and appearance of the various tissues or tissue 
fragments, as well as on the abundance, shape, and distribution of such 
distinctive cell contents as the starches, fat globules, or cr\'stals. 

* One reagent that is really necessary on the microscope-table, and will very often be 
required is iodine in potassium iodide. 



THE MICROSCOPE IN FOOD ANALYSIS. 79 

Analytical reagents are applied to the water-mounted sample by means 
of a glass rod or pipette, with which a drop of the reagent is deposited 
on the sample upon the slide, having previously removed the cover, 
which is afterwards replaced. Or, without removing the cover-glass, a 
drop of the reagent is placed in contact with one side of it on the 
slide. Along the opposite side of the cover is then placed a piece of filter- 
paper. The latter withdraws by capillary attraction a portion of the water 
from under the cover-glass, and this is replaced by the reagent, which 
thus intermingles with the particles of the substance. 

Following is a brief list of the commoner microchemical reagents, 
together with their method of preparation and chief uses. For fuller 
details in this branch of the subject the reader is referred to Poulsen's 
Botanical Microchemistry, translated by Trelease, and Zimmerman's 
Botanical Microtechnique. 

A. Analytical Reagents. — Iodine in Potassium Iodide. — Two grams 
of crystallized potassium iodide are first dissolved in loo cc. of distilled 
water and the solution is saturated with iodine. 

This reagent is indispensable for the identification of starch, especially 
when the latter is present in minute quantities. Starch granules when 
moistened with water are turned blue by iodine, the reaction being exceed- 
ingly delicate under the microscope, even when the starch granules are 
very minute and insignificant without the reagent. 

Iodine in connection with sulphuric acid is also useful in distinguishing 
pure cellulose from its various modifications, such as lignin and suberin. 
For this purpose the water-mounted sample is first permeated with con- 
centrated sulphuric acid, after which the iodine reagent is applied, with 
the result that all pure cellulose is turned a deep-blue color, while the 
modified forms of cellulose are colored yellow or brown. The cellulose 
is first converted by the sulphuric acid into a carbohydrate isomeric with 
starch, known as amyloid. 

Protein grains are colored brown or yellow brown by the action of 
iodine. 

Chloriodide of Zinc. — Pure zinc is dissolved in concentrated hydro- 
chloric acid to saturation, and an excess of zinc added. The solution is 
then evaporated to about the consistency of concentrated sulphuric acid, 
after which it is first saturated with potassium iodide, and finally with 
iodine. 

This reagent may be used instead of sulphuric acid and iodine for the 



8o FOOD INSPECTION JND /IN/t LYSIS. 

detection of cellulose, since the zinc chloride converts the cellulose into 
amyloid, which the reagent colors blue. 

Chloriodide of zinc is useful for detecting tannic acid in cell contents. 
For this purpose the above reagent is much diluted by the addition of 
a 20% solution of potassium iodide. In this diluted form, when applied 
to the sample, a reddish or violet coloration is imparted to cell contents 
having tannin. 

Phenol-hydrochloric Acid is prepared by saturating concentrated 
hydrochloric acid with the purest crystallized carbolic acid. Wood fiber, 
or lignin, when treated with a drop of this reagent under the cover-glass, 
and exposed for half a minute to the direct sunlight, will be colored an 
intense green, which quickly fades. 

Indol. — Several crystals of indol are freshly dissolved in warm water. 
Lignified cell walls assume a deep-red color, when the specimen to be 
examined is treated first with a drop of the indol reagent, and afterwards 
washed with dilute sulphuric acid, i : 4. 

Millon's Reagent. — This is prepared by dissolving metallic mercury 
in its weight of concentrated nitric acid, and diluting with an equal volume 
of water. This reagent, which should be freshly prepared, is of use in 
testing for protein compounds, which turn brick red when treated with it, 
especially on gently warming the slide. 

Tincture oj Alkanna. — A 70 or 80% alcoholic extract of alkanna root, 
when kept in contact with resins, fixed oils, fats, or essential oils for a 
short time, stains these cell contents a lively red. The staining is hastened 
by the aid of heat. Essential oils and resins are soluble in strong alcohol, 
while fixed oils and fats are insoluble, hence the distinction between these 
classes of cell contents may be made by the application of alcohol to the 
alkanna-stained specimen. 

Ferric Chloride, Ferric Acetate, or Ferric Sulphate, used in dilute aqueous 
solution, are all applicable as reagents for tannic acid, which, when present 
in appreciable amount, will be colored green or blue by either of these 
reagents. 

B. Clarifying Reagents. — Many of the harder cellular tissues are too 
opaque for careful examination, and maybe rendered transparent by clarify- 
ing or bleaching. For this purpose a portion of the powdered sample is 
sometimes allowed to soak for hours or even days in the reagent, using a 
drop of the same reagent as a medium for examination on the object-glass, 
instead of water. The clarifying reagents most commonly used arc the 
following : 



THE MICROSCOPE IN FOOD AN/tLYSIS. 8i 

Chloral Hydrate. — A 60% solution. 

Ammonia. — Concentrated, or 28% ammonia is commonly used. 

Potassium Hydroxide, used in various degrees of concentration, often 
in dilute solution, say 5%. This reagent causes swelling of the cell wall, 
and acts as a solvent of intercellular substances as well as of protein. It 
bleaches most of the coloring matters, destroys the starch, and forms 
soluble soaps with the fats. Potassium hydroxide is also used in testing 
for suberin, which is extracted from corky tissue on boiling with the reagent, 
and appears as yellow drops. 

Schullze's Macerating Reagent (concentrated nitric acid and chlorate of 
potassium) is best used by placing the powder or bit of tissue to be treated 
in a test-tube with an equal volume of potassium chlorate crystals, adding 
about 2 cc. of concentrated nitric acid, and warming the tube till bubbles 
are evolved freely, or until the necessary separation of cells is effected. 
The sample is then removed and washed with water. 

By this treatment, bast and wood fibers as well as stone cells are 
readily separated from other tissues. 

Cuprammonia (Schweitzer's Reagent). — This is prepared by adding 
slowly a solution of copper sulphate to an aqueous solution of sodium 
hydroxide, forming a precipitate of cupric hydroxide, which is separated 
by fihration, washed, and dissolved in concentrated ammonia. It should 
be freshly prepared, and is never fit for use unless it is capable of immediately 
dissolving cotton. Indeed its chief use is as a test for cellulose, which it 
readily dissolves. In observing this reaction under the microscope, the 
powdered specimen under the cover-glass should be only slightly damp 
before a drop of the fresh reagent is applied. The cell walls are seen to 
swell up and gradually become more and more indistinct, till they finally 
disappear. 

Cuprammonia is also used as a test for pectose, which occurs in many 
cell walls, often intermixed with cellulose. When treated with this reagent, 
cellular tissue containing pectose is acted upon in such a manner that 
a dehcate framework of cupric pectate is sometimes left behind, after the 
dissolution of the cellulose with which it is mingled.* 

Photomicrography. — The photomicrograph serves as a simple means 
of keeping permanent records of unusual forms of adulteration met with 
during routine examination. Besides this, the photomicrograph has at 
times proved its usefulness as a means of evidence in court, showing as it 
does with faithfulness the presence of a contested adulterant. It is true 

* Poulsen, Botanical Micro-chemistry, p. 15. 



82 



FOOD INSPECTION AND ANALYSIS. 



that from an artistic standpoint the photomicrograph of a powdered 
sample is often disappointing, due to the fact that ordinarily much of the 
field is out of focus, unless a very simple homogeneous subject is photo- 
graphed, as, for instance, starch. As compared with the carefully prepared 
drawing of a section, which is usually idealized, the photomicrograph is 
of course the more truthful representation. 

SUMMARY OF MICROCHEMICAL REACTIONS FOR IDENTIFYING 
CELLULAR TISSUE AND CELL CONTENTS. BASED ON BEHRENS'.* 





Iodine in 

Potassium 

Iodide. 


Chlor- 

iodide of 

Zinc. 


Iodine 
and Sul- 
phuric 
Acid. 


Cupram- 
monia. 


Potassium 
Hydroxide. 


Concen- 
trated 
Sulphuric 
Acid. 


Schiiltze's 
Mixture. 


Cellulose, cell substance. 
Lignin.wood substance. 
Middle lamella, inter- 


Yellow to 

brownish 

Yellow 

Yellow 

Yellow or 
brownish 

Blue 
Brown 
yellow 


Violet 
Yellow 

Yellow 

Yellow or 
brown 


Blue 

Yellow to 
brownish 

Yellow 

Brown 


Dissolves 
Insoluble 

Insoluble 
Insoluble 


Swells up 
Dissolves 


Dissolves 
Dissolves 


Dissolves 

Dissolves 
easily 


Suberin, cork substance. 


Insoluble 

in cold. 

By boiling 

it comes out 

in drops 

Dissolves 

Dissolves 


Insoluble 


easily 
Gives 
eerie 
acid reac- 
tiont 


























Fat 










Saponifies 
























Reddish 
to violet 





























































Phenol- 
h ydro- 
chloric 
Acid. 


Indol. 


Ferric 
Acetate 
or Sul- 
phate. 


Alkanna 
Tincture. 


Hydro- 
chloric 
Acid. 


Acetic 
Acid. 


Millon's 
Reagent. 


Cellulose, cell substance. 
Lignin, wood substance. 

Middle lamella, inter- 


Uncolored 
Green 

Green 
Uncolored 


Uncolored 

Cherry 

red 

Cherry 

red 

Uncolored 






































































Brick red 










Bright red 
Bright red 
Bright red 








Fat. . 


































Blue or 
green 








Calcium oxalate crystals 








Soluble 
witliout ef- 
fervescence 

Soluble 
with effer- 
vescence 


Insoluble 

Soluble 
with effer- 
vescence 































* Microscopical Investigation of Vegetable Substances, page 356- 

+ When treated with the reagent, suberin forms masses of eerie acid, soluble in ether, alcohol, or 
chloroform. 

While the analyst examines microscopically the ordinary powdered 
spice, for example, he constantly moves with his hand the line adjustment- 
screw, bringing into focus different parts of the field successively. This 



THE MICROSCOPE IN FOOD /INALYSIS. 83 

he does unconsciously, so that he docs not realize how far from flat the 
field actually is till he undertakes to photograph it, when, as a rule, only 
a small portion is in good focus. It is therefore impossible in one photo- 
graph to show successively many varied forms of tissue or cell contents 
in the powder, but separate photographs should be made as far as possible 
with only a little in each. Thus, for example, with a composite subject 
like powdered cassia bark, it would be very difficult to show starch, stone 
cells, and bast fibers in one field, all in ecjually good focus, and, for the best 
results only, one, or at most two, such varied groups of elements should be 
shown in one picture. 

Appurtenances and Methods of Procedure. — The temporary method 
of water-mounting employed by the analyst in routine examination pre- 
sents many difficulties from a photographic point of view. The vibrating 
motion of the particles is very annoying, and some skill is required in using 
just the right amount of water, in avoiding air-bubbles, in waiting the 
requisite amount of time before exposing the plate for the vibratory motion 
to cease, and, on the other hand, avoiding too long delay, which would 
result in the evaporation of the water, and the consequent breaking up of 
the field. In the writer's experience, however, in spite of these difficulties, 
the water-mounting gives decidedly the clearest resuhs, and, with patience 
on the part of the operator, it is in many ways the most desirable method of 
mounting for photographic purposes. It is in fact the method employed in 
making most of the photomicrographs of powdered specimens that appear 
in the plates at the end of this volume, though a few were mounted in 
glycerin jelly, and the starches for the polarized-light pictures in Canada 
balsam. The sections of tissues shown in the plates were mounted some 
in glycerin and others in glycerin jelly. 

Experience has shown that two degrees of magnification well cal- 
culated to bring out the chief characteristics of the spices and their adul- 
terants in a photomicrograph are 125 and 250 diameters. The starches, 
which are the most common of any one class of adulterants, vary very 
widely in the size of their granules. With these the larger magnification 
of 250 has been found satisfactory, while the general appearance of the 
composite ground-spice itself under the microscope, as well as that of 
such adulterants as ground bark, sawdust, chicor\', pea hulls, and the 
like, is best shown with the lower power of 125.* 

* The degrees of magnification adopted in the originals of most of the photomicrographs 
illastrated in the accompanying plates are accordingly 125 and 250, but in the process of 
lithographing, the photographs were slightly reduced, so that the actual scales in the repro- 
duction are no and 220 respectively. 



84 



FOOD INSPECTION AND ANALYSIS. 



The object, mounted in the manner above described, is best examined 
when held in a mechanical stage, furnished with micrometer adjust- 
ments, in such a manner that a typical field may be selected and held 
in place long enough to photograph. 

The Camera. — This need not of necessity be complicated, but may 
consist simply of a horizontal wooden base on which the microscope 




Fig. 2g. — A Convenient Photomicrographic Camera. 

rests, and an upright board firmly secured to the base, carrying a frame 

for an interchangeable ground glass and plate-holder, with a rubber 

gauze skirt hanging from the frame, adapted to be gathered and tied 

about the top of the microscope-tube. Means are further provided, as 

by a slotted guide and screw, for adjusting the frame at any desired height 

on the upright board.* 

A more convenient form of apparatus now employed by the writer is 

that shown in Figs. 29 and 30. 

* Such a contrivance as this was employed in making some of the accompanying photo- 
micrographs. 



THE MICROSCOPE IN FOOD ANALYSIS. 



8S 



The base is a solid iron plate upon which the microscope rests (any 
microscope may be used with this camera), and above which the camera 
bellows is supported on two solid steel rods. The bellows is supported 
at either end on wooden frames. 

The ground glass is provided with a central transparent area, formed 
by cementing a cover-glass upon the ground glass, and permits the accurate 
focusing of the most delicate detail by means of a hand magnifying-glass. 
The vertical rods supporting the bellows arc attached to metal arms, 
immovably fixed to a horizontal axis, thus permitting the camera to be tilted 




Fig. 30. — Photomicrographic Camera in Horizontal Position 

to any angle from vertical to horizontal. It is fixed at the desired angle by 
means of heavy hand-clamps. 

In use the camera is placed in a vertical position and the microscope 
adjusted on the base so that its tube will coincide with the opening in 
the front of the camera. The connection between microscope and camera 
is made light-tight by means of a double chamber, which permits consider- 
able vertical motion of the tube of the microscope without readjustment. 
A jointed telescoping rod is attached to the upper end of the camera to 
act as a support, giving perfect steadiness when in a horizontal position, 
and folding down parallel with the bellows so as to be out of the way 
vhen in any other position. 

Amplification. — The vertical rods are graduated in inches for deter- 
mining the amount of amplification, and to show when the ground glass 
is at right angles to the optical axis. The following simple rule for deter- 
mining the amount of amplification will give sufficiently accurate results. 
When photographing without the eyepiece, divide ' the distance of the 
ground glass from the stage of the microscope in inches, by the focal length 
in inches of the objective used. When photographing with the eye- 
piece, proceed as above and multiply the result by the cjuotient obtained 
by dividing 10 by the focus in inches of the eyepiece used. 



86 FOOD INSPECTION AND ANALYSIS. 

Adjustment and Manipulation. — The microscope can be placed in 
any position desired, and the camera adjusted to it. The bellows can then 
be raised and the microscope used as though no camera were present. 
When an object is to be photographed, the bellows may be slid into posi- 
tion without in any way disturbing the arrangement of light or object, 
the final focusing on the ground glass being effected quickly by means of 
the fine adjustment-screw of the microscope. The exposure having 
been made, observation through the microscope may be continued with- 
out interruption by simply raising the bellows again. 

When a water-mounted specimen is to be photographed, the camera 
and microscope tube should be vertical instead of inclined as shown in 
the cut. 

The camera is best kept in a dark room where the exposures are to 
be made, the source of light being a i6- or 32-candle-power electric lamp, 
preferably provided with a ground-glass bulb. The light from this lamp 
is first carefully centered by moving the reflector of the microscope. 

In making pictures, for instance, of the magnification of 250 diameters, 
the objective, having an equivalent focus of \ inch, may be used in 
combination with the one-inch ocular, with the ordinary tube length of 
microscope. For a lower power, such as 125 diameters, the same objec- 
tive is employed, but the eyepiece is left out, it being found necessary 
in this case to remove the upper tube of the microscope, which ordinarily 
carries the eyepiece, as otherwise the size of the field to be photographed 
would be restricted. In each case a diaphragm is used in the microscope 
stage, having an opening of about the same size as that of the front lens 
of the objective. By means of a stage micrometer scale, the proper posi- 
tion of the camera back is previously determined to give the required 
magnification. 

REFERENCES ON THE MICROSCOPE IN FOOD ANALYSIS. 

Alltmann. Die Elementarorganismen und ihre Beziehungen zu den Zellen. Leipzig, 

1890. 
Behrens, J. W. Guide to the Microscope in Botany. Translated by Hervey. Boston, 

1885. 
Bergen, J. Elements of Botany. Gross and Microscopic Structure. Vegetable 

Histology. 
Bessey, C. E. The Essentials of Botany. 

Botany for High Schools and Colleges. New York, 1880. 

BoNsrrELD, E. C. Guide to Photomicrography. London. 

Chamberlain, C. J. Vegetable Tissues. 

Methods in Plant Histology. Chicago, 1901. 



THE MICROSCOPE IN FOOD ANALYSIS. 87 

Clark, C. H. Practical Methods in Microscopy, 1896. 

Dammar, O. lUustrirtes Lexicon der Vcrfalschungen und Vereinigungen der Nahrungs- 
und Genussmittel. Leipzig, 1886. 

Detmer, W. Das pflanzenphysiologische Praktikum. Jena, 1885. 

DiETSCH, O. Die wichtigsten Nahrungsmittel und Getranke, deren Verunreinigungen 
und Verfalschungen. Zurich, 1884. 

Gage, S. H. The Microscop)e and Microscopical Methods. Ithaca, 1894. 

Greenish, H. G. The Microscopical Examination of Foods and Drugs. Philadel- 
phia, 1903. 

Haushofer, K. Mikroskopische Reaktionen. Braunschweig, 1885. 

Hegler. Histochemische Untersuchungen verholzter Zellmembranen. Flora, 1890, 
page 31. 

HOFFMEISTER, T. Die Rohfaser und einige Formen der Cellulose. Landwirtschaftl. 
Jahrbiicher, 1888, page 239. 

Koch, L. Mikrotechnische Mittheilungen. Pringsheim's Jahrbiicher, Bd. XXIV, page 
I, 1892. 

Kraemer, H. Botany and Pharmacognosy. Philadelphia, 1903. 

Kraus, G. Zur Kentniss der Chlorophyllfarbstoffe. Stuttgart, 1872. 

Lange, G. Zur Kentniss des Lignins. Zeits. fiir physiologische Chemie. Bd. XIV, 
page 15. 

Leach, A. E. Microscopical Examination of Foods for Adulteration. An. Rep. 
Mass. State Board of Health, 1900, p. 679. 

Lee, a. B. The Microtomist's Vade Mecum. 1893. 

Mace, E. Les Substances Alimentaire Etudies au Microscope. Paris, 1891. 

Moeller, J. Mikroskopie der Nahrungs- und Genussmittel aus dem Pflanzenreiche. 
Berlin, 1886. 

Pharmacognostischer Atlas. Berlin, 1892. 

MOLISCH. Grundriss einer Histochemie der pflanzlichen Genussmittel. Jena, 1891. 

Neuhauss, R. Lehrbuch der Mikrophotographie. Braunschweig, 1890. 

Poulsen, V. A. Botanical Microchemistry, translated by Trelease. Boston, :886. 

Pringle, a. Practical Photomicrography. New York, 1890. 

ScHiMPER, A. F. W. Mikroskopischen Untersuchungen der Nahrungs- und Genuss- 
mittel. Jena, 1886. 

Strassburger, E. Manual of Vegetable Histology, translated by Hervey. 1887. 

Thomas and Dltdley. A Laboratory Manual of Plant Histology. 

TscHiRCH, A., und Oesterle, O. Anatomischer Atlas der Pharmakognosie und Nahr- 
ungsmittelkunde. Leipzig, 1900. 

VoGL, A. E. Die wichtigsten vegetabilischen Nahrungs- und Genussmittel. Berlin, 
1899. 

WoRHLEY, T. G. The Microchemistry of Poisons. Philadelphia, 1885. 

Zimmerman, A. Botanical Microtechnique. New York, 1893. 

Die Morphologie und Physiologic der Pflanzenzelle. Breslau, 1887. 

Beitrage zur Morphologie und Physiologie der Pflanzenzelle. Tubingen, 1890. 



CHAPTER VI. 
MILK. 

Nature and Composition. — Milk is the secretion of the mammary 
glands of female mammals for the nourishment of their young. Con- 
taining as it does all the requisites for a complete food, i.e., sugar, fat, 
proteids, and mineral ingredients, combined in appropriate proportion, 
there is ample reason why it occupies so high a place in the scale of human 
foods. It is a yellowish-white opaque fluid, denser than water, contain- 
ing in complete solution the sugar, soluble albumin, and mineral content, 
and, in less complete solution, the casein, while the fat-globules are held in 
suspension in the serum, forming an emulsion. 

The specific gravity of pure milk ranges from 1.027 to 1.035. 

Milk from various animals has the same general physical properties 
and the same ingredients, differing, however, in percentage composition. 
Of all the varieties, the milk of the cow is by far the most important from 
its universal use, and, unless otherwise qualified, the term milk wherever 
it occurs in this volume will be understood to mean cow's milk. 

Acidity. — When perfectly fresh, milk of carnivorous mammals is, 
as a rule, acid in reaction, while human milk and that of the herbivora is 
alkaline. Cow's milk, when freshly drawn, is more often amphoteric in 
reaction, i.e., it reacts acid with blue and alkaline with red litmus. It soon 
becomes distinctly acid, and the acidity increases as the milk sugar grad- 
ually becomes converted into lactic acid. 

Microscopical Appearance. — Under the microscope pure milk shows 
a conglomeration of various-sized fat globules having a pearly lustre. 
These globules vary from o.ooi to o.oi mm. in diameter, averaging about 
0.005 mm. When examined under very high powers, it is possible to 
distinguish bacteria in the milk, the number to be seen depending greatly 
on the time that has elapsed since the milk was drawn from its source, 
as well as on the surroundings, the conditions of handling, exposure, etc. 

S8 



MILK. 89 

Color. — The yellow color of milk is imparted to it by the fat globules, 
and varies greatly in milk from different breeds of cattle, as well as in 
milk from the same cow at different seasons, being, as a rule, paler during 
the winter or stall-fed months, and having its greatest intensity soon after 
the cow is put out to pasture. 

Milk Sugar, the carbohydrate of milk, is normally present in amounts 
varying from 3 to 5 per cent. For the properties of milk sugar see page 472. 

The Proteids of Milk. — Casein constitutes nearly 80% of the entire 
proteids of milk, being present in an average sample to the extent of about 
3%. It exists in combination with calcium phosphate, and probably 
does not form a perfect solution in the milk, but is rather diffused therein 
in a somewhat colloidal form, being so finely divided, however, as to be 
incapable of separation by filtration while the milk is fresh. 

Pure casein is a white, odorless, and tasteless solid, sparingly soluble 
in water, and insoluble in ether and alcohol. It is readily soluble in dilute 
alkalies. Strong acids also dissolve it, but its character is changed. From 
alkaline solution it is precipitated without change by neutralizing with 
acid. Its solutions are Isevo-rotary. 

Lact-albumin is the soluble albumin of milk, existing therein to the 
extent of about 0.6% and forming about 15'/^ or more of the milk proteids. 
It much resembles the albumin of eggs, being coagulated at 70° to 75° C. 
It is readily soluble in water. Its specific rotary power according to 
Bechamp is [a]D= —67.5. 

LadoglobuUn has been discovered by Emmerling as a constituent in 
milk, but exists in traces only. According to Babcock, it may be separated 
from milk whey by carefully neutrahzing with sodium hydroxide, and 
afterwards saturating with magnesium sulphate. It much resembles the 
globulin of blood serum, being coagulated at 67° to 76° C. 

Fibrin. — Babcock has discovered in milk very minute traces of a 
substance analogous to the fibrin of blood. This substance, it is claimed, 
forms a part of the slime found in the separator-bowl of a centrifugal 
skimmer. 

Other Nitrogenous Substances. — Besides the above normal constituents 
of milk, certain bodies may be formed by proteolytic action during fer- 
mentation, such, for example, as caseoses and peptones, formed for the 
most part by the decomposition of a part of the casein. Galactin is a 
gelatin-like body of the nature of peptone, occurring in traces in milk. 
Besides these, minute traces of amido-bodies, such as creatin and urea, 
are sometimes present, and also ammonia. 



9° 



FOOD INSPECTION AND ANALYSIS. 



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MILK. 



91 



Milk Fat. — Fat forms the most variable constituent of milk, being 
found in proportions ranging from 2.5 to 7 per cent. For the chemical 
composition and characteristics of milk fats see Butter (p. 431). 

The fat globules are held in suspension in the milk and have long 
been thought to be surrounded each by a thin nitrogenous membrane, 
known as SiorcWs mucoid prolcid, which becomes broken on churning. 
This theory, while rendered probable by many of the phenomena 
connected with the dairy, is by no means universally held at present. 

Citric Acid has been found to exist in milk, probably in combina- 
tion with certain of the mineral constituents, being present to the extent 
of about 0.1%. 

The table on page 90 arranged by Babcock shows cjuite clearly the 
percentage composition of an average cow's milk. 

For comparison of milk from different animals the following table * 
is inserted, showing in most cases minimum, maximum, and mean deter- 
minations from a large number of actual analyses: 



No. of 
Anal- 
yses. 



Specific 
Gravity. 



Water. 



Casein. 


Albu- 
min. 


Total 
Pro- 
teids. 


1.79 
6.29 
3.02 


0.25 
1-44 
0-53 


2.07 
6.40 

3-55 


0.18 
1.96 
I -03 


0.32 
2.36 
1.26 


0.69 
4.70 
2.29 


2.44 
3-94 
3.20 


0.78 

2.01 
1.09 


4.29 


3-59 
5-69 
4-97 


0.83 

1-77 
1-55 


6.52 


1.24 


0-75 


1.99 


0.67 


i-SS 


2.22 



Fat. 



Milk 
Sugar. 



Cow's milk 800 

Minimum. 

Maximum I 

Mean 

Human milk \ 200 

Minimum 

Ma.ximum 

Mean 

Goat's milk 200 

Minimum 

Maximum 

Mean. 



32 



Ewe's milk 

Minimum. ., 

Maximum 

Mean [ 

Mare's milk 47 

Mean 

Ass's milk 5 

Mean I 



1.0264 
1.0370 
I -0315 

1.027 
1.032 

1.0280 
1.0360 
1.0305 

1.0298 
1-0385 
1-0341 

1-0347 

1-036 



89.32 
90.69 
87.17 

81.09 
91.40 
87.41 

82.02 
90. 16 
85-71 

74-47 
87.02 
80.82 

90.78 

89.64 



1.67 
6.47 
3-64 

1-43 

6.83 
3-78 

3-10 

7-55 
4.78 

2.81 
9.80 
6.86 



1.64 



2. II 
6. 12 
4. 88 



3.26 

5-77 
4.46 



•35 
.21 

■71 



3.88 0.12 
8.34 1.90 
6.21 0.31 



0-39 
1.06 
0.76 



2.76 I 0.13 

7-95 I 1-72 

4.91 I 0.89 

5-67 j 0.35 

5-99 I 0-51 



Composition of the Ash of Milk. — The ash of milk does not truly 
represent the mineral content, since, in the process of incineration, the 
character of some of the constituents is altered by oxidation and otherwise. 

Expressed in parts per loo, the ash of the typical milk sample whose 
full analysis is given on page go would be about as follows: 



* Compiled from Konig's Chemie der mens. Nahr. u. Genuss. 



92 



FOOD INSPECTION AND ANALYSIS. 



Potassium oxide 25 . 02 

Sodium " 10.01 

Calcium " 20 . 01 

Magnesium " 2 .42 

Iron " 0.13 

Sulphur trioxide 3 . 84 

Phosphoric pentoxide 24. 29 

Chlorine 14. 28 



100.00 

Soldner regards the following as more nearly representing the propor- 
tion in which the mineral salts exist in milk: 

Per Cent. 

Sodium chloride, NaCL 10.62 

Potassium chloride, KCL 9.16 

Mono-potassium phosphate, KHjPO^ 12.77 

Di-potassium phosphate, KjHPO^ 9.22 

Potassium citrate, K3(CgH507)2 5-47 

Di-magnesium phosphate, MgHPO^ 3.71 

Magnesium citrate, Mg3(CeH50,)3 4.05 

Di-calcium phosphate, CaHPO^ 7.42 

Tri-calcium phosphate, Ca3(PO J , 8 . 90 

Calcium citrate, Ca3(CgH50,)2 23.55 

Lime, combined with proteids 5.13 



100.00 



Fore Milk and Strippings. — Unless a portion drawn from the well- 
mixed or whole complete miU-cing of an animal is taken for analysis, one 
does not get a fair representative sample of the milk, for it is a well-known 
fact that the first portion of milk drawn from the udder, termed the ' ' fore 
milk," is very low in fat, while the last portions or "strippings" con- 
tain a ver)^ high fat content, sometimes exceeding 10% fat. The following 
analyses show the difference between fore milk and strippings in two 
cases : 



(i) Fore milk. 

Strippings. 
(2) Fore milk. 

Strippings. 



Per Cent 
Water. 



»S.I7 
80.82 
88-73 
80-37 



Per Cent 
Solids. 



11.83 
19.18 
11.27 
19-63 



Per Cent 
Fat. 



1-32 

9-63 

1.07 

10.36 



MILK. 



93 



The per cent of albuminoids, sugar, and ash is nearly the same in 
both fore milk and strippings. 

Colostrum. — The milk given by cows and other mammals for two or 
three days after the birth of young is termed colostrum, and differs ma- 
terially in composition from normal milk. It is yellow in color, of an 
oily consistency, and has a pungent taste. It acts as a purge upon the 
young. Examined under the microscope, it is found to contain large 
circular cells larger than fat globules and somewhat similar to blood 
corpuscles. It is very high in albumin, which seems to be similar to 
blood albumin. The following analyses were made by Engling, showing 
the composition of colostrum from a cow eight years old: 



Time after Calving. 



Specific 
Gravity. 


Fat. 


Casein. 


Albu- 
min. 


Sugar. 


Ash. 


1.068 


3-54 


2.6s 


16.56 


3.00 


i.i8 


1 .046 


4.66 


4.28 


9-32 


1.42 


i-SS 


I -043 


4-75 


4-5° 


6.25 


2.85 


1.02 


1.042 


4.21 


3-25 


2-31 


3-46 


o.g6 


1-035 


4.08 


3-33 


i-°3 


4.10 


0.82 



Total 
Solids. 



Immediately. . 

After 10 hours. 
" 24 " • 
" 48 " • 

" 72 " . 



26.93 
21.23 

19-37 
14.19 
13-36 



The average of twenty-two analyses of colostrum from different cows 
by Engling showed total solids 28.31, fat 3.37, casein 4.83, albumin 15.85, 
sugar 2.48, ash 1.78. 

Frozen Milk. — Since it is the water in milk that freezes, it follows 
that in partially frozen milk the unfrozen portion of the milk, or that 
part which remains still liquid, becomes concentrated by the process of 
freezing. This is borne out by the following figures of Richmond : * 

Frozen Portion, TJnfrozen Portion, 
Per Cent. 



Per Cent. 

Water 96 . 23 

Fat 1 . 23 

Sugar 1.42 

Proteids 91 

Ash 21 

Specific gravity i . 0090 



85.62 

4-73 

4-95 

3-90 
.80 

1-0345 

Fermentations of Milk. — These are due to the action of bacteria 
of various kinds, the most common being the lactic fermentation. 

The Souring of Milk is caused by the action of a large number of 
species of acid-forming bacteria, chief among which is the Bacillus acidi 
lactici, which multiplies faster than other bacteria in raw milk under 



* .Analyst, XVIII. p. 53. 



94 FOOD INSPECTION AND ANALYSIS. 

favorable conditions of temperature. Part of the milk sugar is acted 
on and transformed, first into dextrose and galactose, the latter sugar 
subsequently forming lactic acid, as follows: 

(i) C„H,,0,,,H,0 = C,H,,Oe+QH,A 

Lactose Dextrose Galactose 

(2) QH,30„ = 2C3H,03 

Galactose Lactic acid 

More and more acid is formed until the casein can no longer be held 
up, curdling ensues, and the casein is precipitated. Finally, after a 
certain degree of acidity is reached, the ferment is killed and the action 
stops. Other acids than lactic are also undoubtedly produced, since a 
small part of the acid in sour milk is found to be volatile. According 
to Conn * the volatile acids are acetic and formic. 

Abnormal Fermentation. — Through the agency of micro-organisms 
that may develop under certain conditions, various changes are produced 
in milk that to some extent alter its character. Thus bitter milk is some- 
times produced as the result of some organism as yet but little understood. 

Occasionally milk is found possessing a peculiarly thick and slimy 
consistency, whereby it may be drawn out in threads, by dipping a spoon 
into the milk and withdrawing it therefrom. This is termed ropy milk, 
and is more often met with in warm weather. It is undoubtedly produced 
as a result of bacterial action. 

Enzyme- j or ming Bacteria are not uncommonly developed in milk, 
causing various proteolytic changes, whereby the casein is partially trans- 
formed into peptones, cascoses, etc. 

Chromogenic Bacteria are the agencies that produce peculiar pigments 
in milk. Thus red milk is due to Bacillus crythrogcnes; yellow milk to 
Bacillus xynxanthus; blue milk to Bacillus cyanagenes. The latter is 
quite common, appearing ordinarily in patches in the milk. 

CHEMICAL ANALYSIS OF MILK. 

Ordinarily, in ascertaining the nutritive value of milk, one determines 
its specific gravity, total sohds, fat, proteids, milk sugar, and ash. Occa- 
sionally it is thought desirable to make a distinction in the case of proteids 
between the casein and the albumin. Rarely is it necessary to further 
subdivide the nitrogenous bodies in milk, unless in connection with a 
special study of the proteolytic changes which it undergoes. 

The total solids, fat, and ash are usually all determined directly, and, 

* U. S. Dept. of .^gric, Og. of Exp. Stations, Bui. 25, p. 21. 



MILK. 



95 



Mm 



in the case of the milk sugar and the proteids, a determination of cither 
one may be directly made (whichever is most convenient), the other being 
calculated by difference. 

WTien foreign ingredients or adulterants are present in milk, special 
methods are employed to detect them. 

Preparation of the Sample. — In procuring a sample for analysis, 
the greatest care is necessary to insure a homogeneous sample. By far 
the best method in every case, where possible, is to pour the milk back 
and forth from one vessel to another (i.e., pour from the original container 
into an empty vessel and back at least once). Where 
such procedure is impossible from the size of the con- 
tainer or for any other reason, a so-called "sampler" 
should be used, of which the Scovell sampling-tube 
is a convenient form. By means of this, a small sample 
for analysis representative of the whole is obtainable, 
which can afterwards be mixed by pouring. 

This instrument consists of a brass or copper tube 
made in two parts which telescope accurately together as 
shown in Fig. 31, the lower part being closed at the 
bottom, but provided with three or more lateral slits. 
The sampler, drawn out to its full length, is carefully 
inserted in the tank containing the milk and lowered 
to the bottom, after which the upper part is pressed 
down over the lower so as to close the sHts, and the 
tube is then lifted out of the tank, containing a fairly 
representative sample of the milk. 

In all operations to which a milk sample is submitted 
during the process of analysis, it should invariably be 
poured into a clean empty vessel and back, whenever it 
has been at rest for an appreciable time, in order to 
insure a homogeneous mixture. 

Determination of Specific Gravity. — This is most 
readily obtained with the aid of a hydrometer, accurately 
graduated whhin the limits of the widest possible varia- Fig. 31. Fig. 32. 
tion in the specific gravity of milk. Hydrometers for Fig. 31.— The Sco- 
special use with milk are known as lactometers, and are If , ' "^^™P °S 
graduated variously. One of the most convenient forms fig. 32.— The Que- 
of this instrument is the Qucvcnne lactometer, graduated venne Lactometer, 
from 15° to 40°, corresponding to specific gravity 1.015 to 1.040. This 



I 



96 



FOOD INSPECTION /1ND /IN/4LYSIS. 



instrument, shown in Fig. 32, has a thermometer combined with it, the 
stem containing a double scale, on the lower part of which the specific 
gravity is read, while the temperature is read from the upper part. 

Another form of instrument is termed the New York Board of Health 
lactometer, which is not graduated to read the specific gravity directly, but 
has an arbitrary scale divided into 120 equal parts, the zero being equal 
to the specific gravity of water, while 100 corresponds to a specific gravity 
of 1.029. To convert readings on the New York Board of Health scale 
to Quevenne degrees they must be multiplied by .29. 



QUEVENNE LACTOMETER DEGREES CORRESPONDING TO NEW YORK 
BOARD OF HEALTH LACTOMETER DEGREES. 



Board of 
Health 
Degrees. 


Quevenne 
Scale. 


Board of 
Health 
Degrees. 


Quevenne 
Scale. 


Board of 
Health 
Degrees. 


Quevenne 
Scale. 


60 


17-4 


81 


23-5 


lOI 


29-3 


61 


17.7 


82 


23.8 


102 


29.6 


62 


18.0 


83 


24.1 


I°3 


29.9 


63 


18.3 


84 


24.4 


104 


30.2 


64 


18.6 


85 


24.6 


105 


3°-S 


65 


18.8 


86 


24.9 


106 


30-7 


66 


19. 1 


87 


25.2 


107 


31-0 


67 


19.4 


88 


25-5 


108 


31-3 


68 


19.7 


89 


25.8 


109 


31.6 


69 


20.0 


90 


26.1 


no 


31-9 


70 


20.3 


91 


26.4 


III 


32.2 


71 


20.6 


92 


26.7 


112 


32. S 


72 


20.9 


93 


27.0 


"3 


32.8 


73 


21.2 


94 


27-3 


114 


33-1 


74 


21-5 


95 


27.6 


"5 


33-4 


75 


21.7 


96 


27.8 


116 


33-6 


76 


22.0 


97 


28.1 


117 


33-9 


77 


22.3 


98 


28.4 


iiS 


34.2 


78 


22.6 


99 


28.7 


119 


34-5 


79 


22.9 


100 


29.0 


120 


34.8 


80 


23.2 











If extreme accuracy is desired, the Westphal balance or the pycnometer 
should be used for the determination of specific gravity. For ordinary 
cases, however, the lactometer, if carefully made, is sufficiently accurate. 

With any other form of lactometer than the Quevenne, a separate 
thermometer is necessary in order to determine the temperature, the 
common practice being to standardize all such instruments at 60° F. 
(15.6° C). 

Readings at temperatures other than 60° may be corrected to that 
temperature by the aid of the following table: 



MILK. 



97 



FOR CORRECTING THE SPECIFIC GRAVITY OF MILK ACCORDING TO 
TEMPERATURE (BY DR. PAUL VIETH). 



Degrees 

of 
Lactom- 
eter. 



Degrees of Thermometer (Fahrenheit). 



45 



46 



48 



49 



52 



55 



56 



58 



59 



19. 

19-9 
20. 9 
21 .9 
22.9 
23.8 
24.8 
25.8 
26.7 
27.7 
28.6 
29-5 
3°-4 

32.2 
33-0 



19. 
20. 
21 . 
22. 
22. 

23- 

24. 

26. 

27- 

28. 
29. 

3°- 
31- 
32- 
a- 



I9.i|i9. 
20.1 20. 

21. 1 : 
22.1 



23-1 

24.0 

25 

26.0 
26.9 

27.9 
28.8 
29.7 
30.6 
31-5 

34-4 



5 
33-4133-5 



2119. 

2 20. 
.221. 
.2 22. 
.2,23. 
.::24'. 

•I|2S- 
.1 26. 
.027. 
,028. 
,0 29. 

■9|30-' 
931-' 
SJ31-' 

732-' 
633-: 



19.4 
20.3 
21.3 
22.3 
23-3 
24-3 
25.2 
26.2 
27.2 
28.2 
9-1 
30-1 
31-1 
32.0 

33-9 



19.6J19 
20.6,20 
21.621 
22.6I22 
623 



26.5 

27-.S 
28.5 

29-4 
30-4 
31-4 
32-4 
i3-i 
34.3 



19.8 

20.8 

21 . 

22.8 

23-7 

24-7 

2,S-7 

6-7 
27.7 
28.7 

29-7 
30.6 
31.6 
32.6 
33-6 
34-6 



19 



.8 



19.9 
20.9 
21 .9 
22.9 
9 
9 



23 

24 

25-9 

26.9 

27.9 

28.9 

29.9 

3°-9 

31-9 

32-9 

33-9 

34-9 





6t 


62 


63 


64 


6s 


66 


67 


68 


69 


70 


71 


72 


73 


74 


75 


20 


20.1 


20.2 


20.2 


20.3 


20.4120.5 


20.6 


20.7 


20.9 


21.0 


21. 1 


21.2 


21-3 


21.5121.6 


21 


21. I 


21.2 


21-3 


21.4 


21-5 


21.6 


21.7 


21.8 


22.0 


22.1 


22.2 


22.3 


22.4 


22.5 22.6 


22 


22.1 


22.2 


22.3 


22.4 


22.5 


22.6 


22.7 


22.8 


23.0 


23-1 


23.2 


23-3 


23-4 


23-5 23-7 


23 


23-1 


23.2 


23-3 


23-4 


23-5 


23.6 


23-7 


23-8 


24.0 


24.1 


24.2 


24-3 


24.4 


24.6,24.7 


24 


24.1 


24.2 


24-3 


24.4 


24-5 


24.6 


24.7 


24-9 


25.0 


25-1 


25.2 


25-3 


2,S-5 


25-6 


25-7 


2"; 


2S-I 


25.2 


2S-3 


25-4 


25-5 


25.6 


25-7 


25.9 


26.0 26.1 


26.2 


26.4 


26.5 


26.6 


26.8 


26 


26.1 


26.2 


26.3 


26-5 


26.6I26.7 


26.8 


27.0 


27.1 27.2 


27-3 


27-4 


27-5 


27-7 


27.8 


27 


27.1 


27-3 


27-4 


27-'5 


27-6,27.7 


27.8 


28.0 


28.1 28.2 


28., 


28.4 


28.628.7 


28.9 


28 


28.1 


28.3 


28.4 


28.5 


28.628.7 


28.8 


29.0 


29.1 29.2 


29-4 


29-5 


29.729.8 


29.9 


29 


29.1 


29-3 


29.4 


29-5 


29.6 29.8 


29.9 


30.1 


30.230-3 


30.4 


30-5 


30.7 


30.9 


31-0 


30 


3°-i 


3°-3 


30-4 


3° -5 


30-730-8 


30.9 


31-1 


31-2,31-3 


31-5 


31.6 


31.8 


31-9 


32-1 


31 


31-2 


i^-i 


31-4 


31-5 


3I-73I-7 


31-8 


32.0 


32.232.4 


32-5 


32.6 


32.8 


33 -o 


33-1 


32 


32-2 


32-3 


32-5 


32.6 


32-7!32-9 


33-0 


33-2 


33-3J33-4 


?,?,.b 


33-7 


33-9 


34-° 


34.2 


33 


33-2 


ii-i 


33-5 


33-6 


33-833-9 


34-0 


34.2 


.34.3'34-5 


34.6 


34-7 


,34.9 


35-1 


35.2 


34 


.34-2 


34-3 


34-5 


34-6j34.8 34.9 


35-035-2 


35-3|35-5 


35.6 


35.8 


36.0 


36.1 


36.3 


35 


35-2 


35-3 


35-5 


35-635-8 35-9 


36.1J36.2 


36.4,36.5 


36.7 


36.8 


37-0 


37-2 


37-3 



Determination of Total Solids. — For purposes of milk analysis, plat- 
inum dishes are by far the most desirable. These, if made for the purpose, 
should be of the shape shown in Fig. 33, measuring about 2| inches in 




33. — Platinum Milk Dish. 



diameter at the top, and 2\ inches in diameter at the bottom, having care- 
fully rounded rather than square edges, and being \ inch deep. The 
bottom is not perfectly flat, but sHghtly crowned outward. Such a dish 
will hold about 35 cc. 



98 FOOD INSPECTION ^ND ANALYSIS. 

For purposes of economy it is best to have these dishes spun out with 
a thick bottom, but with thin sides, not so thin, however, as to be too 
readily bent. 

If platinum dishes cannot be afforded, dishes of porcelain, glass, alu- 
minum, nickel, or even tin may be used, but in all cases should be as 
thin as practicable. 

About 5 cc. of the thoroughly mixed sample of milk are carefully 
transferred by means of a pipette to a tared dish on the scale-pan, and its 
weight accurately determined. The dish with its contents is then trans- 
ferred to a water-bath, being placed over an opening preferably but little 
smaller than the diameter of the bottom of the dish, so that as large a 
surface as possible is in contact with the live steam of the bath. Here 
it is kept for at least two hours, after which the dish is wiped dry while 
still hot, transferred to a desiccator, cooled, and weighed.* 

Determination of Ash. — The platinum dish containing the milk residue 
is next placed upon a suitable support above a Bunsen flame (a platinum 
triangle or a ring stand is convenient for this) and the residue is ignited at 
a dull-red heat to a perfectly white ash, after which it is cooled and weighed. 

Determination of Fat. — The Adams Method. — Without doubt 
the most accurate method of fat determination is the so-called Adams 
method. For this purpose a strip of fat-free filter-paper about 2i inches 
wide and 22 inches long is rolled into a coil and held in place by a wire as 
shown in Fig. 34. 

Schleicher and Schiill furnish fat-free strips especially for this work, 
but it is very easy to prepare the strips and extract them with the Soxhlet 
apparatus. 

About 5 grams of milk are run into a beaker with a pipette, and the 
weight of the beaker and milk are determined. The coil is then intro- 
duced into the beaker, holding it by the wire in such a manner that as 

* It is a common practice to transfer the milk residue, after a preliminary drying on the 
water-bath, to an air-oven, kept at a temperature of from ioo° to 105°, where it is dried to 
a constant weight; but after an experience in analyzing over 30,000 samples of milk, the 
author is prepared to state that in his opinion the results obtained by the above method of 
procedure, using the water-bath alone, are more satisfactory. It is impossible to keep a 
milk residue at a temperature above 100° for any length of time without its undergoing 
decomposition, especially as to its sugar content, as is shown by the darkening in color. A 
milk residue should be nearly pure white, a brownish color showing incipient decomposi- 
tion. Hence, by continued heating, especially at the temperature of 105°, the residue would 
continue to lose weight almost indefinitely. If it is thought best to give a final drying in 
the air-oven, the time should be short and the temperature employed should not in any case 
exceed 100°. 



MILK. 



99 



much as possible of the milk is absorbed by the paper. It is often possible 
to talce up almost the last drop of the milk. By then weighing the beaker, 
the amount of milk absorbed by the coil is determined Ijy difference, and 
the paper coil is hung up and dried, first in the air and then in the oven, 
at a temperature not exceeding ioo°. Another method of charging 
the paper coil consists in suspending it by the wire and gradually deliver- 
ing upon it 5 cc. of the milk from a pipette, the density of f\ 
the milk being known. 

The coil containing the dried residue is then transferred 
to the Soxhlet extraction apparatus (see p. 57) and sub- 
jected to continuous extraction with anhydrous ether for at 
least two hours, the receiving-flask being first accurately 
weighed. The tared flask with its contents is freed from 
all remaining ether, first on the water-bath and finally in 
the air-oven. It is then cooled and weighed, the increase 
in weight representing the fat in the amount of milk ab- 
sorbed by the coil. If there is any doubt about all the 
fat having been extracted at first, the process of extraction 
may be continued till there is no longer a gain in weight 
of the flask. Experience soon shows the length of time 
necessary for the complete extraction, which of course 
depends on the degree of heat employed, and the fre- 
quency with which the extracting-tube overflows. Two hours is ample 
for most cases, in which the conditions are such that the ether siphons 
over from the extraction-tube ten times per hour. 

Fat Methods Based on Centrifugal Separation. — These 
methods are the most practicable for commercial work and for use by 
the public analyst, since they are much more rapid, and, if carefully 
carried out, practically as accurate as the Adams method. They all 
depend upon the use of a centrifugal machine, having hinged pockets 
in which are carried graduated bottles, into each of which a measured 
quantity of milk is introduced. The milk is then subjected to the action 
of a suitable reagent, which dissolves the casein and liberates the fat in 
a pure state, after which, by whirling at a high speed, the pockets are 
throwTi out horizontally and the milk fat driven into the neck of each 
bottle, where the amount is directly read. 

Various processes of this kind, each having its own special adherents, 
are in extensive use, among which the best known are the Babcock, the 
Leffman and Beam, the Gerber, and the Stokes. 




Fig. 34. — The 
Adams Milk- 
fat Coil. 



i.^c 



FOOD INSPECTION /IND AN /I LYSIS. 



A resume of these processes, showing the reagents employed and other 
comparative data, is thus tabulated by Allen.* 



Milk 

Sulphuric acid, volume 

" " specific gravity. 

Hydrochloric acid 

Amvl alcohol 



Babcock. 



Leffman- 
Beam. 



17-5 cc. 15 cc. 

17.5 cc. 9 cc. 

1. 831 to 1.834 1.85 



Gerber. 



None 
None 



i-S cc. 
1.5 cc. 



II cc. 

10 cc. 
1.82 to 1.825 
None 
i.o cc. 



Stokes. 



15 cc. 

I3i cc. 

1.82 to I. 

None 

1-5 cc. 



83 



The Babcock Process, devised originally for the use of creameries 
and dairymen, is now extensively employed for fat determination in 
the laboratory'. 

It has stood the test of over ten years' successful use in the writer's 
hands. During this time on various occasions results as determined 
have been compared with those obtained by the Adams process, and the 
agreement has been as close as could be expected. The following figures 
show the results of such comparative determinations made in duplicate 
on three samples of milk, viz., a whole pure milk, (1) and (2); a watered 
milk, (3) and (4); and a milk centrifugally skimmed, (5) and (6). 

COMPARATIVE FAT DETERMINATION BY ADAMS-SOXHLET AND BY 
BABCOCK PROCESSES. 





Per Cent of 

Fat by the 

Adams-Soxh- 

let Process. 


Per Cent of 

Fat by the 

Babcock 

Process. 


A 'whnle milk (i) 


4-27 
4.28 
2.70 

2-74 
0.16 
0.14 


4-3° 
4-35 
2-7° 
2.80 
o.is 
0.15 


(2) 




(4) 




(6) 





The Centrifuge. — Various styles of centrifuge are in use for this process, 
some driven by hand, some by steam-power, and some by the electric 
motor, carrying from 4 to 40 bottles. Fig. 35 shows an 8-bottle hand 
machine, driven by friction gearing, as well as the steam-driven centrifuge 
in common use in dairies and creameries, which is a 20-bottle machine 
having paddles on the outer periphery of the revolving frame, against 
which the steam impinges, driving it like a horizontal water-wheel. 

The most noiseless and easy-running machine is that driven by an 
electric motor. Of this type is the Robinson centrifuge, shown in Fig. 
36, carrying 16 bottles. 

* Commercial Organic Analysis, IV. p. 150. 



MILK. 



lOI 




Fig. 35. — Types of the Babcock Centrifuge and Appurtenances. Hand machine at the 
left; steam-driven machine at the right. 




Fig. 36. — Electrically-driven Babcock Centrifuge, with Aluminum Frame, Carrj'ing 16 

Bottles. Acid burette at the left. 

A sheet-metal safety-shield (removed for showing the construction) normally surrounds the 

instrument. Such a shield is shown in Fig. ir. 



I02 FOOD INSPECTION AND ANALYSIS. 

The ordinary Babcock test bottle is shown in Fig. 37, that used for 
skimmed milk in Fig. 38. The bottles are graduated with reference to 
using 18 grams of the sample. 

Manipulation. — By means of a pipette graduated to hold 17.6 cc. 
(the average volume of 18 grams) that amount of the thoroughly mixed 
sample of milk to be tested is transferred to a test bottle, and 17.5 cc. of 
commercial sulphuric acid of a specific gravity of 1.82 to 1.84 are added 




Fig. 37. — Babcock Milk-test 
Bottle. 



Fig. 38.— Babcock Test Bottle 
for Skimmed Milk. 



by means of a graduate or an automatic burette, shown in Fig. 35. The 
contents are then thoroughly mixed, during which operation much heat is 
developed by the action of the acid on the proteids and milk sugar, and the 
mixture turns a very dark brown. The test bottles are then placed in the 
centrifuge pockets (an even number being always used, arranged opposite 
each other to properly balance) and whirled for at least five minutes. 
Hot water is then added up to the necks of the bottles, which are then again 
whirled for about two minutes. Enough hot water is then added to drive 
the fat into the neck of each bottle, and a final whirl of about a minute's 
duration is given, after which the bottles are removed from the pockets, 
and the percentage of fat is read, while still hot, from the graduated neck 
by means of a pair of calipers. 



MILK. '03 

The Werner-Schmidt Method.— Ten cc. of milk arc introduced by 
means of a pipette into a large test-tube of 50 cc. capacity, and 10 cc. of 
concentrated hydrochloric acid are added. The mixture is shaken and 
heated till the hquid turns a dark brown, either by direct boiling for a 
minute or two, or by immersing the tube in boiling water for from five to 
ten minutes. The tube is then cooled by im- 
mersion in cold water, and 30 cc. of washed ether 
is added. The tube is closed by a cork provided 
with tubes similar to a wash-bottle, the larger 
tube being adapted to slide up and down in the 
cork, and preferably being turned up slightly at 
the bottom. The contents of the tube are 
shaken, the ether layer allowed to separate, and 
the sliding-tube arranged so that it terminates 
slightly above the junction of the two layers. 
The ether is then blown out into a weighed 
flask. A second and a third portion of ether 
of 10 cc. each are successively shaken with the 
acid Hquid and added to the contents of the 
weighed flask, from which the ether is subse- 
qucntlv evaporated and the weight of the fat 

casilv obtained. FlG.39.-TheWerner-Sct,midt 

..... . Fat Apparatus. 

Instead of measurmg the milk mto the testmg- 
tube, a known weight of milk may be operated on. A sour milk may be 
readily tested in this way, provided it is previously well mi.xed. 

Determination of Fat by the Wollney Milk-fat Refractometer.* — This 
instrument presents the same appearance as the butyro-refractometer, 
Fig. 91, with an arbitrary scale reading from o to 100, the equivalent 
readings in indices of refraction of the Wollney instrument varying from 
1.3332 to 1.4220. Exactly 30 cc. of the milk to be tested are measured 
into the stoppered flask A, Fig. 40. This may be done by the use of 
the automatic pipette, which holds exactly 75 cc, removing four pipettes 
full of the milk. J5 is a numbered tin sampling-tube in which the milk 
sample is kept for convenience, and into which the automatic pipette 
readily fits. Having measured 30 cc. of the milk into the flask A, 12 
drops of a solution of 70 grams potassium bichromate and 312.5 cc. of 
stronger ammonia in one liter of water may be added as a preservative, 

* Milch Zeit., 1900, pp. 50-53. 




I04 



FOOD INSPECTION AND ANALYSIS. 



if the sample is to be kept for some time before finishing the test. Twelve 
drops of glacial acetic acid are added to curdle the milk. The flask is 
then corked and shaken for one to two minutes in a mechanical shaker, 
after which 3 cc. of a standard alkaline solution are added, and the flask 
corked and shaken for ten minutes in the mechanical shaker, the tempera- 
ture being kept at i7.5°C. The standard alkaline solution is prepared 




Fig. 40. — .Accessories for Caming Out the WoUney Milk-fat Process. 



by dissolving 800 cc. of potassium hydroxide in a liter of water, adding 
600 cc. of glycerin and 200 grams pulverized copper hydrate, the mixture 
being allowed to stand for several days before using, shaking at intervals. 
Finally 6 cc. of water-saturated ether are added to the mixture in the 
flask, using for convenience the automatic pipette fitted in the corked 
bottle as shown. The flask is again shaken for fifteen minutes in the 
mechanical shaker, and whirled for three minutes in the centrifuge, after 
which a few drops of the ether solution are transferred to the refractometer, 
and the reading taken. The percentage of fat is obtained by means of 
the following table: 



MILK. 



'°S 



PERCENTAGES OF FAT CORRESPONDING TO SCALE READINGS ON THE 
WOLLNEY REFRACTOMETER. 



Scale 


Per 


Scale 


Per 


Scale 


Per 


Scale 


Per 


Scale 


Per 


Scale 


Per 


Read- 


Cent 


Read- 


Cent 


Read- 


Cent 


Read- 


Cent 


Read- 


Cent 


Read- 


Cent 


ing. 


Fat. 


ing. 


Fat. 


ing. 


Fat. 


ing. 


Fat. 


ing. 


Fat. 


ing. 


Fat. 


20.0 




24-5 


0.41 


29.0 


0.87 


33-S 


1.34 


38.0 


1.8s 


42-5 


2.41 


I 




6 


0.42 


I 


0.88 


6 


1-35 


I 


1.87 


6 


2-43 


2 




7 


0-43 


2 


0.89 


7 


1.36 


2 


1.88 


7 


2.44 


3 




8 


0.44 


3 


0.90 


8 


1-37 


3 


1.89 


8 


2.46 


4 




9 


0.45 


4 


0.91 


9 


1.38 


4 


1.90 


9 


2.47 


S 




25.0 


0.46 


5 


0.92 


34-0 


1-39 


5 


1. 91 


43-° 


2.49 


6 


0.00 


I 


0.47 


6 


0-93 


I 


1.40 


6 


1.92 


I 


2.50 


7 


O.OI 


2 


0.48 


7 


0.94 


2 


1.42 


7 


1-93 


2 


2-51 


8 


0.02 


3 


0.49 


8 


°-95 


3 


1-43 


8 


1.94 


3 


2.52 


9 


0.03 


4 


0.50 


9 


0.96 


4 


1.44 


9 


1-95 


4 


2-54 


21.0 


0.04 


5 


°-5i 


30.0 


0.97 


5 


1-45 


39-° 


1.96 


5 


2-55 


I 


0.05 


6 


0.52 


I 


0.98 


6 


1.46 


I 


1.98 


6 


2.56 


2 


0.06 


7 


°-S3 


2 


0-99 


7 


1.47 


2 


1.99 


7 


2-58 


3 


0.08 


8 


0-54 


3 


1. 00 


8 


1.48 


3 


2.00 


8 


2.60 


4 


o.og 


^ 9 


0-55 


4 


1. 01 


9 


1.49 


4 


2.02 


9 


2.61 


5 


O.IO 


26.0 


°-S7 


5 


1.02 


3S-0 


1-5° 


S 


2.03 


44.0 


2.63 


6 


O.II 


I 


0.58 


6 


1.03 


I 


I-5I 


6 


2.04 


I 


2.64 


7 


0.12 


2 


0-59 


7 


1.04 


2 


1-52 


7 


2.05 


2 


2.65 


8 


0-13 


3 


0.60 


8 


I -OS 


3 


1-54 


8 


2.07 


3 


2.67 


9 


0.14 


4 


0.61 


9 


1.06 


4 


i-SS 


9 


2.08 


4 


2.68 


22.0 


o-'S 


5 


0.62 


31.0 


1.07 


s 


1.56 


40.0 


2.09 


5 


2.70 


I 


0.16 


6 


0.63 


I 


1.08 


6 


1-57 


I 


2.10 


6 


2.71 


2 


0.17 


7 


0.64 


2 


1.09 


7 


1.58 


2 


2.12 


7 


2.72 


3 


0.18 


8 


0.65 


3 


1. 10 


8 


1-59 


1 3 


2-13 


8 


2.74 


4 


0.19 


9 


0.66 


4 


I. II 


9 


1.60 


i 4 


2.14 


9 


2-75 


S 


0.20 


27.0 


0.67 


S 


1. 12 


36.0 


1. 61 


5 


2-15 


45 -o 


2-77 


6 


0.21 


I 


0.68 


6 


I-I3 


I 


1.62 


6 


2.16 


I 


2.78 


7 


0.22 


2 


0.69 


7 


1. 14 


2 


1.64 


7 


2.18 


2 


2-79 


8 


0.23 


3 


0.70 


8 


i-iS 


3 


1.65 


8 


2.20 


3 


2.80 


9 


0.24 


4 


0.71 


9 


1. 16 


4 


1.66 


9 


2.21 


4 


2.82 


23-0 


0.25 


s 


0.72 


32.0 


1. 17 


5 


1.67 


41.0 


2.23 


5 


2.84 


I 


0.26 


6 


0-73 


I 


1. 18 


6 


1.68 


I 


2.24 


6 


2.85 


2 


0.27 


7 


0.74 


2 


1. 19 


7 


1.69 


2 


2.25 


7 


2.87 


3 


0.28 


8 


°-75 


3 


1.20 


8 


1.70 


3 


2.26 


8 


2.88 


4 


0.29 


9 


0.76 


4 


1.22 


9 


1. 71 


4 


2.27 


^ 9 


2. 89 


5 


0.30 


28.0 


0.77 


S 


1-23 


37-0 


1.72 


5 


2.28 


46.0 


2.90 


6 


0.31 


I 


0.78 


6 


1.24 


I 


1-73 


6 


2.30 


I 


2.92 


7 


0.32 


2 


0.79 


7 


1-25 


2 


1-75 


7 


2.32 


2 


2-93 


8 


°-33 


3 


0.80 


8 


1.26 


3 


1.76 


8 


2-33 


3 2.94 


9 


0-34 


4 


0.81 


9 


1.27 


4 


1.78 


9 


2.34 


4 


2.96 


24.0 


0.36 


s 


0.82 


ii-° 


1.28 


5 


1-79 


42.0 


2-35 


S 


2.98 


I 


°-37 


6 


0.83 


I 


1.29 


6 


1.80 


I 


2-37 


6 


3.00 


2 


0.38 


7 


0.84 


2 


1-30 ! 


7 


1. 81 


2 


2.38 


7 


3-OI 


3 


0-39 


8 


0.85 


3 


1-31 


8 


1.82 


3 


2-39 


8 


3.02 


4 


0.40 


9 


0.86 


4 


1-32 


9 


1.84 


4 


2.40 


9 


3-03 


5 0-41 


29.0 


0.87 


5 


1-34 


3S.0 


1-85 


5 


2.41 


47.0 


3-°5 



io6 



FOOD INSPECTION AND ANALYSIS. 



PERCENTAGES OF FAT CORRESPONDING TO SCALE READINGS ON THE 
WOLLNEY REFRACTOMETER —{Continued). 



Scale 


Per 


Scale 


Per 


Scale 


Per 


Scale 


Per 


Scale 


Per 


Scale 


Per 


Read- 


Cent 


Read- 


Cent 


Read- 


Cent 


Read- 


Cent 


Read- 


Cent 


Read- 


Cent 


ing. 


Fat. 


ing. 


Fat. 


ing. 


Fat. 


ing. 


Fat. 


ing. 


Fat. 


ing. 


Fat. 


47.0 


3-05 


S°-5 


3-59 


54-0 


4.18 


57-5 


4-78 


61.0 


5-44 


64-5 


6.14 


I 


3-06 


6 


3.60 


I 


4.20 


6 


4.80 


I 


5-46 


6 


6.i6 


2 


3.08 


7 


3.61 


2 


4.22 


7 


4.82 


2 


5-48 


7 


6.18 


3 


3-IO 


8 


iM 


3 


4-23 


8 


4-84 


3 


5-5° 


8 


6.20 


4 


3-12 


9 


3-64 


4 


4-25 


9 


4.86 


4 


5-52 


9 


6.22 


5 


3-14 


Si-o 


3-66 


5 


4.26 


58.0 


4.88 


5 


5-54 


65.0 


6.24 


6 


3-iS 


I 


3-67 


6 


4.28 


I 


4-9° 


6 


S-56 


I 


6.27 


7 


3-16 


2 


3-68 


7 


4-29 


2 


4.92 


7 


5-58 


2 


6.29 


8 


3-17 


3 


3-7° 


8 


4-31 


3 


4-94 


8 


5.60 


3 


6-31 


9 


3-i8 


4 


3-72 


9 


4-33 


4 


4-95 


9 


5.61 


4 


6.34 


48.0 


3.20 


5 


3-74 


55-° 


4-35 


5 


4-97 


62.0 


5-63 


5 


6.36 


I 


3-21 


6 


3-76 


I 


4-37 


6 


4.98 


I 


5-65 


6 


6-38 


2 


3-23 


7 


3-78 


2 


4-38 


7 


5.00 


2 


5-66 


7 


6.40 


3 


3-25 


8 


3.80 


3 


4-4° 


8 


5.02 


3 


5-68 


8 


6.42 


4 


3-27 


9 


3-82 


4 


4.42 


9 


5-°4 


4 


5-7° 


9 


6.44 


S 


3-28 


52.0 


3-84 


5 


4-43 


59-° 


5.06 


5 


5-72 


66.0 


6.46 


6 


3-30 


I 


3-85 


6 


4-44 


I 


5.08 


6 


5-74 






7 


3-i^ 


2 


3-87 


7 


4-46 


2 


5-1° 


7 


5-76 






8 


3-33 


3 


3-89 


8 


4.48 


3 


5-11 


8 


^■f 






9 


3-34 


4 


3-9° 


9 


4-49 


4 


5-13 


9 


5.80 






49.0 


3-36 


5 


3-92 


56.0 


4-51 


5 


5-15 


1 63.0 


S-82 






I 


3-38 


6 


3-93 


I 


4-S3 


6 


5-17 


j I 


S-84 






2 


3-40 


7 


3-95 


2 


4-55 


7 


5-19 


1 2 


5-86 






3 


3-42 


8 


3-97 


3 


4-57 


8 


5-2° 


1 3 


5-88 






4 


3-43 


9 


3-99 


4 


4-59 


9 


5-22 


1 4 


5-9° 






S 


3-44 


S3-0 


4.01 


5 


4.60 


60.0 


5-24 


' 5 

1 


5-92 






6 


3-45 


I 


4-03 


6 


4.61 


I 


5-26 


i ' 


5-94 






7 


3-46 


2 


4.04 


7 


4-63 


2 


5-28 


' 7 


5-96 






8 


3-48 


3 


4.06 


8 


4-65 


3 


5-3° 


8 


5-98 






9 


3-5° 


4 


4.07 


9 


4.67 


4 


5-32 


9 


6.00 






50.0 


3-51 


5 


4.09 


57-° 


4.69 


5 


5-34 


64.0 


6.02 






1 


3-53 


6 


4.10 


I 


4.71 


6 


5-36 


I 


6.04 






2 


3-55 


• 7 


4-12 


2 


4-73 


7 


5-38 


2 


6.07 






3 


3-56 


8 


4.14 


3 


4-75 


8 


5-40 


3 


6.09 






4 


3-57 


9 


4.16 


4 


4-76 


9 


5-42 


4 


6.12 






S 


3-59 


54-0 


4.18 


5 


4.78 


61.0 


5-44 


S 


6.14 







The following table is of use for those who wish to employ the 
WoUney method, but have the Abbe refractometer instead of the milk-fat 
refractometer. 



MILK. 



107 



INDICES OF REFRACTION (n„) CORRESPONDING TO SCALE READINGS OF 
THE WOLLNEY MILK-FAT REFRACTOMETER. 



Refrac- 








Fourth Decimal of n „• 










tive 






















Index. 






















«D- 





1 


2 


3 


4 


5 


6- 


7 


8 


9 










Scale Readings. 










1-333 
1-334 






0.0 


0. 1 


2 


0-3 
1 . 2 


0.4 
1-3 


0-5 
1-4 


0.5 

1-5 


0.6 


0-7 


' ' 0.8 " 


0-9 


1.0 


I 


I 


1.6 


I -335 


1-7 


1.8 


1-9 


2.0 


2 


I 


2.1 


2.2 


2-3 


2.4 


2-5 


1-336 


2.8 


2-7 


2.8 


2-9 


3 





3-1 


3-2 


3-3 


3-4 


3-5 


1-337 


3-6 


3-7 


3-7 


3-8 


3 


9 


4.0 


4-1 


4-2 


4-3 


4-4 


1-338 


4-5 


4-6 


4-7 


4.8 


4 


9 


5-0 


5-1 


5-2 


5-3 


5-4 


1-339 


5-5 


5-6 


5-7 


5-8 


5 


9 


6.0 


6.1 


6.2 


6.3 


6.4 


1-340 


6-5 


6.6 


6-7 


6.8 


6 


9 


6.9 


7-0 


7-1 


7-2 


7-3 


1-341 


7-4 


7-5 


7-6 


7-7 


7 


8 


7-9 


8.0 


8.1 


8.2 


8-3 


1-342 


8.4 


8-5 


8.6 


8-7 


8 


8 


8-9 


9.0 


9-1 


9-2 


9-3 


1-343 


9-4 


9-5 


9.6 


9-7 


9 


8 


9-9 


10. 


10. 1 


10.2 


i°-3 


1-344 


10.4 


10.5 


10.6 


10.7 


10 


8 


10.9 


II. 


II. I 


II. 2 


11-3 


I -345 


II. 4 


"-5 


11-5 


II. 6 


II 




II. 8 


II. 9 


12.0 


12. 1 


12.2 


1-346 


12-3 


12.4 


12.5 


12.6 


12 




12.8 


12.9 


13-0 


I3-I 


13-2 


1-347 


13-3 


13-4 


13-5 


13.6 


13 




13-8 


13-9 


14.0 


14. 1 


14.2 


1-348 


14-3 


14.4 


14-5 


14.6 


14 




14.8 


14.9 


15-0 


15-1 


15-2 


1-349 


15-3 


15-4 


15-5 


15-6 


15 




15.8 


15-9 


16.0 


16. 1 


16.2 


1-35° 


16.3 


16.4 


16.5 


16.6 


16 




16. 8 


16.9 


17.0 


17. 1 


17.2 


1-351 


17-3 


17-4 


17-5 


17.6 


17 




17.8 


17.9 


18.0 


18. 1 


18.2 


1-352 


18.3 


18.4 


18.5 


18.6 


18 




18.8 


18.9 


19.0 


19. 1 


19.2 


1-353 


19-3 


19.4 


19-5 


19.6 


19 




19.8 


19.9 


20.0 


20.1 


20.2 


1-354 


20.3 


20.4 


20. s 


20.6 


20 




20.8 


20.9 


21.0 


21. 1 


21 .2 


1-355 


21-3 


21.4 


21-S 


21.6 


21 




21.8 


21.9 


22.0 


22.1 


22.2 


1-356 


22.3 


22.4 


22.5 


22.6 


22 




22.8 


22.9 


23-0 


23-1 


23-2 


1-357 


^i-i 


23-4 


23-S 


23.6 


23 




23.8 


23-9 


24.0 


24.1 


24.2 


1-358 


24-3 


24-4 


24-5 


24.6 


24 




24.8 


24.9 


25.0 


25-1 


25.2 


1-359 


25-3 


25-4 


25-5 


25-6 


25 




25-8 


25-9 


26.0 


26.1 


26.2 


1.360 


26.3 


26.4 


26.1; 


26.6 


26 


7 


26.8 


26.9 


27.0 


27.1 


27-3 


I -361 


27-4 


27-5 


27.6 


27-7 


27 


8 


27.9 


28.0 


28.1 


28.2 


28.3 


1.362 


28.4 


28.5 


28.6 


28.7 


28 


8 


28.9 


29.0 


29.1 


29.2 


29-3 


1-363 


29-4 


29-5 


29.6 


29.7 


29 


8 


29.9 


30.0 


3°-i 


30.2 


30-3 


1.364 


30-4 


30-5 


30.6 


30.7 


30 


8 


31-0 


31-1 


31-2 


31-3 


31-4 


1-365 


31-5 


31-6 


31-7 


31-8 


31 


9 


32-0 


32-1 


32.2 


32-3 


32-4 


1-366 


32-5 


32-7 


32-8 


32-9 


33 





33-1 


33-2 


33-3 


33-4 


33-5 


1-367 


33-6 


33-7 


33-8 


33-9 


34 





34-2 


34-3 


34-4 


34-5 


34-6 


1-368 


34-7 


34-8 


34-9 


35 -o 


35 


I 


35-2 


35-3 


35-4 


35-5 


35-6 


1-369 


35-7 


35-8 


36.0 


36.1 


36 


2 


36.3 


36-4 


36.5 


36.6 


36-7 


1-370 


36.8 


36.9 


37-0 


37-1 


37 


2 


37-3 


37-4 


37-6 


37-7 


37-8 


1-371 


37-9 


38.0 


38-1 


38-2 


38 


3 


38-4 


38.5 


38.6 


38-7 


38.8 


1-372 


38-9 


39-0 


39-2 


39-3 


39 


4 


■ 39-5 


39-6 


39-7 


39-8 


39-9 


1-373 


40.0 


40.1 


40.2 


40-3 


40 


4 


40- 5 


40.7 


40.8 


40.9 


41.0 


1-374 


41-1 


41.2 


41-3 


41.4 


41 


5 


41.6 


41.8 


41-9 


42.0 


42.1 


1-375 


42.2 


42-3 


42.4 


42.5 


42 


6 


42.7 


42.8 


42.9 


43-0 


43-1 


1-376 


43-2 


43-3 


43-4 


43-6 


43 


7 


43-8 


43-9 


44.0 


44-1 


44-2 


1-377 


44-3 


44-4 


44-6 


44-7 


44 


8 


44-9 


45-0 


45-1 


45-2 


45-3 


1-378 


45-4 


45-6 


45-7 


45-8 


45 


9 


46.0 


46.1 


46.2 


46.3 


46.4 


1-379 


46.6 


46.7 


46.8 


46.9 


47 





47-1 


47-2 


47-3 


47-4 


47-6 



io8 



FOOD INSPECTION AND ANALYSIS. 



INDICES OF REFRACTION («d) CORRESPONDING TO SCALE READINGS OF 
THE WOLLNEY MILK-FAT REFRACTOMETER— (Confanweii). 



Refrac- 








Fourth Decimal of "^ 












tive 






















Index. 






















"1>- 





1 


2 


3 


4 


5 


6 


7 


8 


9 












Scale Readings. 










1.380 


47-7 


47-8 


47-9 


48.0 


48.1 


48.2 


48-3 


48.4 


48.6 


48.7 


1. 381 


48.8 


48.9 


49.0 


49-1 


49-2 


49-3 


49-4 


49-6 


49 


7 


49-8 


1.382 


49-9 


50.0 


50-1 


50.2 


5°-3 


50-4 


50.6 


50-7 


50 


8 


5°-9 


1-383 


Si-o 


51-1 


51-2 


51-3 


51-4 


51.6 


51-7 


51-8 


51 


9 


52.0 


1-384 


52-1 


52.2 


52-3 


52-4 


52-6 


52-7 


52.8 


52-9 


53 





53-1 


1-385 


53-2 


53-3 


53-4 


53-6 


53-7 


53-8 


53-9 


54-0 


54 


I 


54-2 


1.386 


54-3 


54-4 


54-6 


54-7 


54-8 


54-9 


5S-0 


55-1 


55 


2 


55-3 


1-387 


55-4 


5S.6 


55-7 


55-8 


55-9 


56.0 


56-1 


56-2 


56 


3 


56-5 


1.388 


56.6 


56.7 


56.8 


56.9 


57-1 


57-2 


57-3 


57-4 


57 


6 


57-7 


1.389 


57-8 


57-9 


58.0 


58-1 


58-2 


58.3 


58-4 


58.6 


58 


7 


58.8 


1.390 


58.9 


59-0 


59-1 


59-2 


59-4 


59-5 


59-6 


59-8 


59 


9 


60.0 


I -391 


60.1 


60.2 


60.3 


60.4 


60.6 


60.7 


60.8 


60.9 


61 





61. 1 


1.392 


61.3 


61.4 


61-5 


61.6 


61.8 


61.9 


62.0 


62.1 


62 


2 


62.3 


1-393 


62.4 


62.6 


62.7 


62.8 


62.9 


63.0 


63-2 


63-3 


63 


4 


63-5 


1-394 


63.6 


63.8 


63-9 


64.0 


64.1 


64.2 


64-4 


64-5 


64 


6 


64-7 


1-395 


64.8 


61;. 


65-1 


65-2 


65-3 


65-4 


6s. 6 


65-7 


65 


8 


65-9 


1.396 


66.0 


66.2 


66.3 


66.4 


66.5 


66.6 


66.8 


66.9 


67 





67.1 


1-397 


67.2 


67.4 


67-5 


67.6 


67.7 


67.8 


67.9 


68.1 


68 


2 


68.3 


1.398 


68.4 


68.6 


68.7 


68.8 


68.9 


6g.o 


6g.i 


69-3 


69 


4 


69-5 


1-399 


69.6 


69.8 


69.9 


70.0 


70.1 


70.2 


70.4 


7°-5 


70 


6 


70.8 


1.400 


70.9 


71.0 


71. 1 


71.2 


71-4 


71-5 


71.6 


71.8 


71 


9 


72.0 


1. 401 


72.1 


72.2 


72.4 


72-5 


72.6 


72.8 


72-9 


73-0 


73 


I 


73-2 


1.402 


73-4 


73-5 


73-6 


73-8 


73-9 


74.0 


74-1 


74.2 


74 


4 


74-5 


1-403 


74.6 


74.8 


74-9 


75-° 


75-1 


75-2 


75-4 


75-5 


75 


6 


75-8 


1.404 


75-9 


76.0 


76.1 


76.2 


76.4 


76.5 


76.6 


76.8 


76 


9 


77.0 


1-405 


77-1 


77-2 


77-4 


77-5 


77-7 


77-8 


77-9 


78.1 


78 


2 


78.3 


1.406 


78.5 


78.6 


78.7 


78.8 


79.0 


79-1 


79.2 


79-4 


79 


5 


79-6 


1.407 


79.8 


79-9 


80.0 


80.1 


80.2 


80.4 


80.5 


80.6 


80 


8 


80.9 


1.408 


81.0 


81. 1 


81.2 


81.4 


81.5 


81.6 


81.7 


81.9 


82 





82.1 


1.409 


82.3 


82.4 


82.5 


82.6 


82.8 


82.9 


83.0 


83.2 


83 


3 


83-4 


1. 410 


83.6 


83-7 


83.8 


84.0 


84.1 


84.2 


84.4 


84-5 


84 


6 


84.8 


1. 411 


84-9 


Ss-o 


85.2 


85-3 


85-4 


85-5 


85.6 


85-7 


85 


9 


86.1 


1. 412 


86.2 


86.3 


86.5 


86.6 


86.7 


86.9 


87.0 


87.1 


87 


3 


87.4 


I-413 


87-5 


87.7 


87.8 


87.9 


88.1 


88.2 


88.3 


88.5 


88 


6 


88.7 


1-414 


88.9 


89.0 


89.1 


89-3 


89.4 


89.6 


89.7 


89.9 


90 





90.1 


1-41S 


90.2 


90.4 


90-5 


90.6 


90.8 


90.9 


91.0 


91.2 


91 


3 


91-5 


1. 416 


91 .6 


91-7 


91.9 


92.0 


92.1 


92-3 


92.4 


92-5 


92 


7 


92.8 


1. 417 


92.9 


93-1 


93-2 


93-3 


93-5 


93-6 


93-8 


93-9 


94 





94.2 


1. 418 


94-3 


94-4 


94-6 


94-7 


94-8 


95-0 


95-1 


95-3 


95 


4 


95-6 


1. 419 


95-7 


95-8 


96.0 


96.1 


96-3 


96.4 


96.6 


96.7 


96 


8 


97.0 


1.420 


97-1 


97-3 


97-4 


97-6 


97-7 


97-8 


98.0 


98.1 


98 


3 


98.4 


1. 421 


98-5 


98-7 


98.8 


99.0 


99-1 


99-3 


99-4 


99-5 


99 


7 


99-9 


1.422 


100. 





















MILK. 109 

Determination of Proteids. — For determination of the total nitro- 
gen in millc, 5 cc. are measured direct into a Kjeldahl digestion-flask, 
or a known weight from a weighing-bottle may be used, and the regular 
Gunning method is employed as described on page 61, proceeding with 
the digestion at once without evaporation. 

The total nitrogen, multiplied by 6.38, gives the total proteids. By 

many the old factor of 6.25 is still employed, but in view of the fact that 

both casein and albumin have been found to contain 15.7% of nitrogen, 

there would seem to be the best reasons for employing 6.38 as a factor 

100' 

15-// 
Ritthausen's Method. — Ten grams of milk are measured into a beaker 

and diluted with water to about 100 cc. Five cc. of a solution of copper 
sulphate (strength of Fehling's copper solution, 34.64 grams CuSO,, in 500 cc. 
of water) are added and the mi.xture stirred. A solution of sodium hydrox- 
ide (25 grams to the liter) is added cautiously a httle at a time, till the 
liquid is nearly, but not quite neutral, avoiding an excess of alkali, as 
this would prevent the complete precipitation of the proteids. Allow the 
precipitate to settle, and pour off the supernatant liquid through a weighed 
filter, previously dried at 130° C. Wash a number of times by decantation, 
and transfer the precipitate to the filter, being careful to remove the por- 
tions adhering to the sides of the beaker with a rubber-tipped rod. Wash 
thoroughly with water, and drain dry, after which the precipitate is washed 
with strong alcohol, dried, extracted with ether, preferably in a Soxhlet 
extractor, and then transferred on the filter to the oven, dried at 130° C, 
and weighed. The filter and precipitate are then burnt to an ash in a 
porcelain crucible, and the weight of the residue subtracted from the first 
weight gives that of the proteids. 

Richmond * recommends modifying this process to the extent of 
neutralizing the milk, using phenolphthalein as an indicator, before adding 
the copper sulphate solution, and using only 2.5 cc. of the latter. 

Determination of Casein. — Official Method oj the A. 0. A. C. — Ten 
grams of the milk are placed in a beaker, and made up with water to about 
100 cc. at 40° to 42° C. One and one-half cc. of a 10% solution (by weight) 
of acetic acid are added, the mixture stirred, warmed to the above tem- 
perature, and allowed to stand for from three to five minutes, till a floccu- 
lent precipitate separates, leaving a clear supernatant liquid. Decant 

* Dain' Cheni., p. 107. 



no FOOD INSPECTION AND /tN A LYSIS. 

upon a filter, wash with cold water two or three times by decantation, 
and finally transfer the whole of the precipitate to the filter, and, after 
filtering, wash two or three times. The filtrate should be clear or nearly 
so. If not, it can generally be made so by repeated filtrations, and the 
washing done afterwards. The filter containing the washed precipitate 
is transferred to the Kjeldahl digestion-flask and the nhrogen obtained 
by the Gunning process. Nx 6.38 = casein. 

Provisional Magnesium Sulphate Method. — A solution of magnesium 
sulphate, saturated at from 40° to 45°, is prepared, and 50 cc. are added 
to 5 grams of milk, the mixture being heated to about 45° till the precipitate 
forms and settles out, leaving a clear supernatant liquid. The liquid 
is first decanted through a filter, and the precipitate collected thereon and 
washed several times with the above saturated magnesium sulphate solu- 
tion, the temperature being kept at about 45° during the operation. The 
precipitate, with filter, is transferred to a digestion-flask, and the nitrogen 
determined. 

Determination of Albumin. — Optional Methods oj the A.O. A. C. — To 
the filtrate from the direct determination of casein by the magnesium 
sulphate method as above described, or to the filtrate from the acetic acid 
method neutralized with sodium hydroxide, 0.3 cc. of a 10% solution 
of acetic acid is added, and the mixture is boiled till the albumin is com- 
pletely precipitated. The precipitate is collected on a filter and washed, 
the nitrogen being determined in the precipitate, and the factor 6.38 * 
used in calculating the albumin therefrom. 

Leflman and Beam's Modified Method jar Albumin and Casein. — Owing 
to the tedious processes of washing and filtering incidental to the above 
methods for determining casein, the following is suggested. Twenty cc. of 
the milk are mixed with saturated magnesium sulphate solution, and 
the mixture saturated with the powdered salt. The whole is then washed 
into a graduate with a little of the saturated solution, and the precipitate 
allowed to settle, leaving a clear supernatant layer. The volume of 
the mixture in the graduate is read, and as much as possible of the clear 
portion is withdrawn by a pipette and filtered. 

An aliquot part of the filtrate is then taken, and the albumin is precip- 
itated from it by a solution of tannin, after which the precipitate is washed 
in a fiher and the nitrogen determined therein. Nx 6.38 = albumin. 

The casein is calculated by difference' between the total proteids and 
the albumin. 



* 6.25 is the factor of the A. O. A. C. 



MILK. I 1 1 

Determination of Nitrogen as Caseoses, Amido-compounds, Peptones, 
and Ammonia. — Van Slyke * proceeds as follows: The filtrate from 
the determination of the albumin, page no, is heated to 70° C, i cc. of 
50% sulphuric acid is first added, and afterwards chemically pure zinc 
sulphate to saturation. The mixture is allowed to stand at 70° until the 
caseoses separate out and settle. Cool, filter, wash with a saturated zinc 
sulphate solution slightly acidified with sulphuric acid, and determine 
the nitrogen of the caseoses in the precipitate. 

For Amido-compounds and Ammonia treat 50 grams of the milk in a 
250-cc. graduated flask with i gram sodium chloride and a 12% solution 
of tannin, added drop by drop till no further precipitate is formed. Dilute 
to the 250-cc. mark, shake, and filter. Determine the nitrogen in 50 cc. 
of the filtrate, the result being the combined nitrogen of the amido-com- 
pounds and ammonia. 

Distil with magnesium oxide 100 cc. of the filtrate from the tannin salt 
solution, receiving the distillate in a standardized acid, and titrating in 
the usual way for the ammonia. 

Calculate the nitrogen of the peptones by subtracting from the total 
nitrogen that due to all other forms. 

Van Slyke has furnished the following unpublished analysis of a 
sample of milk three months old, kept utidcr antiseptic conditions by 
chloroform . 



Per Cent 
Total N. 


Per Cent 
Sol. Nitrogen. 


Per Cent 

N as Paranuclein. 

Caseoses, and 

Peptones. 


Per Cent 
N as Amides, 


0.561 


0.099 


0.074 


0.025 



Determination of Milk Sugar.— if a polariscope is available, the 
sugar of milk can most readily and conveniently be determined by 
optical methods. In the absence of a polariscope, the reducing power of 
milk sugar on copper salts may be utilized quite accurately in deter- 
mining the sugar, using either volumetric or gravimetric methods as 
desired. 

Determination by Optical Methods. — Reagents. — Acid Nitrate of 
Mercury. — This solution is prepared by dissolving metallic mercury 
in twice its weight of nitric acid of specific gravity 1.42, and adding to 
the solution an equal volume of water. One cc. of this reagent will be 



' N. Y. E.xp. Station, Bui. 215, p. 102 



112 



FOOD INSPECTION AND AN/ILYSIS. 



found sufficient to precipitate the proteids and fat completely from 65 grams 
of milk, but if more is employed the result of the analysis is not affected. 

Mercuric Iodide Solution. — 33.2 grams of potassium iodide are mixed 
with 13.5 grams of mercuric chloride, 20 cc. of acetic acid, and 640 cc. 
of water. 

Suhacetate 0} Lead Solution, U. S. P. See p. 481. 

Notes. — For the Laurent polariscope, in which the normal weight 
for sucrose is 16.19 grams, the corresponding normal weight for lac- 
tose is 20.496, while for the Soleil-Ventzke instrument, in which the su- 
crose normal weight is 26.048 grams, the corresponding lactose normal 
weight is 32.975.* 

It is customary to employ three times the normal weight of milk 
in the case of the Laurent instrument (viz., 61.48 grams) and twice the 
normal weight in the case of the Soleil-Ventzke (viz., 65.95 grams). 

As it is more convenient to measure the milk than to weigh it, and 
as the volume varies with the specific gravity, the following table is use- 
ful, showing the quantity to be measured in any case, having first deter- 
mined the specific gravity. 



Specific Gravity. 


Volume of Milk to be Used. 


For Polariscopes of 

which the Sucrose 

Normal Weight is 

16.19 Grams. 


For Polariscopes of 

which the Sucrose 

Normal Weight is 

26.04S Grams. 


1.024 
1.026 
1.028 
1.030 
1.032 
1-034 
i-°3S 


60.0 cc. 
59-9 cc. 
50.8 cc. 
59-7 cc. 
59-6 cc. 
59-5 cc. 
59-35 cc. 


64.4 CC. 

64.3 cc. 
64. 15 cc. 
64.0 cc. 
63.9 cc. 
63.8 cc. 
63.7 cc. 



. For ordinary work it is sufficiently close to have a pipette gradu- 
ated to deliver 59.7 cc. if the Laurent instrument is used, and 64 cc. for 
the Soleil-Ventzke. 

The Process. — Aleasure, as above, the equivalent of 61.48 grams of 
the milk for the Laurent, or 65.95 grams for the Soleil-Ventzke, instru- 
ment into a loo-cc. graduated flask, add, in order to clarify, 2 cc. of acid 
nitrate of mercury solution, or 30 cc. of mercuric iodide solution, or 10 cc. 
of lead subacetate solution. Shake gently and fill to the mark with 

* [a]z) for lactose= 52.53, [aju for sucrose=66.5, hence for the Laurent instrument 

52.53 : 66.5 ;: 16.19 : 20.496, 
andfor the Soleil-Ventzke instrument 52.53 166.5 •• 26.048 : 32.975. 



MILK. ■ 113 

water. Then add from a pipette enough water to make up for the vokime 
of the precipitated proteids and fat, insuring 100 cc. of sugar solution. 
If the Laurent instrument is used, the amount added as prescribed by 
the A. O. A. C. is 2.4 cc, and with the Soleil-Ventzke 2.6 cc. The con- 
tents of the flask are then shaken and poured upon a dry fiUer. The 
fiUratc, which should be perfectly clear, is polarized in a 200-mm. tube, 
and the reading, divided by 3 for the Laurent and by 2 for the Soleil- 
Ventzke, gives the percentage of lactose directly. 

Allowance jor the Volume oj the Precipitate. — This of course varies 
with the content in proteids and fat, and while the above allowance gives 
in most cases sufficiently close results, it is not exact. Leffman and 
Beam * advise that the amount of water to be added above 100 cc. be 
calculated in each case from the percentage of proteids and fat previously 
found by analysis, muhiplying the actual weight of the fat in grams in 
the sample taken by 1.075, '^^d the weight of proteids by 0.8, the sum 
of the two results being the volume in cubic centimeters occupied by 
the precipitate. 

All the calculations are avoided by employing the double-dilution 
method, which is to be recommended when very particular results are 
required. 

Wiley and Ewell's Double-dilution Method.f — Two flasks are em- 
ployed graduated at 100 and 200 cc. respectively, into each of which 
are introduced 65.95 grams of milk, if the Soleil-Ventzke instrument is 
used (or 61.48 grams in case the Laurent is used) and 4 cc. of the mer- 
curic nitrate solution are added, both flasks being filled to the mark and 
shaken. The contents are filtered and the polarization is made in each 
case in a 400-mm. tube. 

The second reading (that of the more dilute solution) is multiplied 
by 2, and the product subtracted from the first reading; the remainder 
is then multiplied by 2, and the product subtracted from the first read- 
ing (that of the stronger or 100 cc. solution). The result is the cor- 
rected reading, which, divided by 4, gives the e.xact per cent of milk sugar 
in the sample. This method depends on the fact that within ordinary 
limits the polarizations of two solutions of the same substance are 
inversely proportional to their volumes. 

Determination of Milk sugar by Fehlikg's Solution.— Twenty- 
five grams of the milk (24.2 cc.) are transferred to a 250-cc. flask, 0.5 cc. of 

* Milk and Milk Products, p. 38. 

t Wiley's Agricultural Analysis, p. 278; .Analyst, 21, 1896, p. 182. 



114 FOOD INSPECTION AND /4N/1 LYSIS. 

a 30% solution of acetic acid are added and the contents well shaken. 
After standing for a few minutes, about 100 cc. of boiling water are run 
in, the contents again shaken, 25 cc. of alumina cream are next added, 
the flask shaken once more, and set aside for at least ten minutes. The 
supernatant liquid is then poured upon a previously wetted ribbed filter, 
and finally the whole contents of the flask are brought thereon, and the 
filtrate and washings made up to 250 cc. The filtrate must be perfectly 
clear. The milk sugar in a solution thus precipitated would ordinarily 
not exceed ^ of i per cent. 

Volumetric Fehling Process. — From a burette containing the clear 
milk sugar solution above prepared, run a measured volume into the 
boiling Fehling liquor containing 5 cc. each of copper and alkali solution 
till sufficient has been introduced to completely reduce the copper, con- 
ducting the operation in the manner described in detail on page 486. 

As 0.067 gram of milk sugar will reduce 10 cc. of FeUing solution 
(see p. 488), it follows that the number of cubic centimeters of sugar- 
containing solution required for making the test (using preferably the 
average of several determinations) will contain 0.067 gram of milk 
sugar, from which the percentage is readily computed. Thus if 16 cc. 
of the milk sugar solution arc necessary to reduce the copper, then 16 
cc. contain 0.067 gram milk sugar. 

250 cc. of solution contain 25 grams milk, 
ICC. " " " 0.1 " 

i6cc. " " " 1.6 " 

and 1.6 grams milk contain 0.067 gram milk sugar. Therefore the 

.067X100 „ 

sample contams = 4.19%. 

Gravimetric Fehling Processes. — O'Sullivan-Dejren Method. — Twenty- 
five cc. of the above milk sugar solution are added to the hot mixture of 
15 cc. each of Fehling copper and alkali solutions and 50 cc. water, pre- 
pared as directed on page 486, and the test carried out in accordance with 
the details there described. The weight of the cupric oxide, CuO, as 
formed, may be roughly calculated to anhydrous milk sugar by multiply- 
ing by 0.6024. 

For more accurate results, however, the Defren table, page 490, should 
be used. 

So.xhlet's Method.* — Twenty-five cc. of milk are diluted with 400 cc. 
of water in a half-liter graduated flask and 10 cc. of Fehling's copper solu- 
* U. S. Dept. of Agric, Bur. of Chem., Bui. 46, p. 41. 



MILK. IIS 

tion are added. Then 8.8 cc. of half-normal sodium hydroxide arc run in, 
or a sufficient quantity to nearly but not quite neutralize, the solution 
being still slightly acid. The flask is filled to the mark, shaken, and the 
contents filtered, using a dry fdtcr. 

One hundred cc. of the filtrate are added to 50 cc. of the mixed Fehling 
solution, which is boiled briskly in a beaker (using 25 cc. each of the 
copper and alkali solution), .\fter boiling for six minutes, filter rapidly 
through a Gooch crucible provided with a layer of asbestos as described on 
I)agc 489, and wash with boiling water till free from alkali. The asbestos 
film with the adhering cuprous oxide is washed into a beaker by hoi dilute 
nitric acid, and after complete solution of the copper is assured, it is again 
filtered and washed with hot water till a clean solution containing all the 
copper is obtained. Add 10 cc. of dilute sulphuric acid (containing 200 cc. 
of sulphuric acid, specific gravity 1.84 per liter) and evaporate on the steam- 
bath till the copper has largely crystallized, then carefully continue the 
heating over a hot plate till the nitric acid is driven out, as evidenced by 
the white fumes of sulphuric. Add 8 or 10 drops nitric acid (specific 
gravity 1.42) and rinse into a very clean tared platinum dish of about 
100 cc. capacity, in which the copper is deposited by electrolysis. See 
page 493. 

The weight of milk sugar is determined from that of copper found, 
from the table on page 116. 

Relation between Specific Gravity, Fat, and Total Solids of Milk.^ 
The close relationship existing between these factors has long been 
known, and many formulas have been devised, whereby, if two of them 
are known, the third may be computed with considerable approach to 
accuracy. The specific gravity and the fat are very readily determined 
by any dairyman, by the aid of a lactometer and the Babcock apparatus. 
The total solids are ascertained with more difficulty, since the use of more 
involved and costly apparatus is necessary, besides considerable tech- 
nical skill. It is therefore common for producers to calculate the total 
solids from the fat and specific gravity, using one of the many tables pre- 
pared for the purpose, based on some one of the best accepted formulce. 
The total solids can thus be calculated to within two or three tenths of 
a per cent. 

The two most commonly used formulae for this purpose are those of 
Hehner and Richmond in England, and Babcock in the United States. 
Hehner and Richmond's formula is 

r = o.255+ 1. 2/^-1-0.14, 



ii6 



FOOD INSPECTION AND ANALYSIS. 



SOXHLET'S TABLE FOR 


THE DETERMINATION OF LACTOSE.* 


Milli- 


Milli- 


Milli- 


Milli- 


MUli- 


Milli- 


Milli- 


MUli- 


Milli- 


Milli- 


grams 


grams 


grams 


grams 


grams 
of Cop- 


grams 


grams 


grams 


grams 


grams 


of Cop- 


of Lac- 


of Cop- 


of Lac- 


of Lac- 


of Cop- 


of Lac- 


of Cop- 


of Lac- 


per. 


tose. 


per. 


tose. 


per. 


tose. 


per. 


tose. 


per. 


tose. 


lOO 


71.6 


161 


117. 1 


221 


162.7 


281 


209.1 


341 


256-S 


lOI 


72.4 


162 


117. 9 


222 


163.4 


282 


209.9 


342 


257-4 


I02 


73-1 


163 


118. 6 


223 


164.2 


283 


210.7 


343 


258.2 


i°3 


73-8 


164 


119. 4 


224 


164.9 


284 


211-5 


344 


259.0 


104 


74-6 


165 


120.2 


225 


165-7 


285 


212.3 


345 


259-8 


105 


75-3 1 


166 


120.9 


226 


166.4 ' 


286 


213. 1 


346 


260.6 


106 


76.1 


167 


121. 7 


227 


167.2 


287 


213-9 


347 


261 .4 


107 


76. S 


168 


122.4 


228 


167.9 


288 


214.7 


348 


262.3 


108 


77-6 


169 


123.2 


229 


168.6 


289 


215-5 


349 


263.1 


log 


78.3 


170 


123-9 


230 


169.4 


290 


216.3 


350 


263.9 


no 


79-° 


171 


124.7 


231 


1 70. 1 


291 


217. 1 


351 


264.7 


III 


79-8 


172 


125-5 


232 


170.9 


292 


217.9 


352 


265.5 


112 


80.5 


173 


126.2 


233 


171. 6 


293 


218.7 


353 


266.3 


"3 


81.3 


174 


127.0 


234 


172.4 


294 


219-5 


354 


267.2 


114 


82.0 


175 


127.8 


235 


173-1 


29s 


220.3 


355 


268.0 


"S 


82.7 


176 


128-5 


236 


173-9 


296 


221. 1 


356 


268.8 


116 


83-5 


177 


129-3 


237 


174.6 


297 


221.9 


357 


269.6 


117 


84-2 


178 


130. 1 


238 


175-4 


298 


222.7 


358 


270.4 


118 


85.0 


179 


130.8 


239 


176.2 


299 


223-5 


359 


271.2 


119 


85-7 


180 


131-6 


240 


176.9 


300 


224-4 


360 


272.1 


120 


86.4 


181 


132-4 


241 


177-7 


301 


225.2 


361 


272.9 


121 


87.2 


182 


133-1 


242 


178-5 


302 


225.9 


362 


273-7 


122 


87.9 


'c^ 


133-9 


243 


179-3 


303 


226.7 


363 


274-5 


123 


88.7 


184 


134-7 


244 


180. 1 


304 


227-5 


364 


275-3 


124 


89.4 


185 


135-4 


245 


180.8 


305 


228.3 


365 


276.2 


125 


90.1 


186 


136.2 


246 


181. 6 


306 


229.1 


366 


277.1 


126 


90.9 


187 


137-0 


247 


182.4 


307 


229.8 


367 


277-9 


127 


91.6 


188 


137-7 


248 


183.2 


.^o8 


230.6 


368 


278.8 


128 


92.4 


189 


138-5 


249 


184-0 


309 


231-4 


369 


279-6 


129 


93-1 


190 


139-3 


250 


184.8 


310 


232.2 


370. 


280.5 


130 


93-8 


191 


140.0 


251 


185-S 


3" 


232-9 


371 


281.4 


131 


94-6 


192 


140.8 


252 


186.3 


312 


233-7 


372 


282.2 


132 


95-3 


193 


141. 6 


253 


187-1 


313 


234-5 


373 


283.1 


133 


96.1 


194 


142-3 


254 


187.9 


314 


235-3 


374 


283-9 


. 134 


96.9 


195 


I43-I 


255 


188.7 


315 


236.1 


375 


284.8 


13s 


97-6 


196 


143-9 


256 


189.4 


316 


236-8 


376 


285-7 


136 


98.3 


197 


144.6 


257 


190.2 


317 


237-6 


377 


286.5 


'37 


99-1 


198 


145-4 


258 


191. 


318 


238-4 


378 


287.4 


138 


99.8 


199 


146.2 


259 


191. 8 


319 


239-2 


379 


28S.2 


139 


100.5 


200 


146-9 


260 


192-5 


320 


240.0 


380 


289.1 


140 


101.3 


201 


147-7 


261 


193-3 


321 


240-7 


381 


289,9 


141 


102.0 


202 


148.5 


262 


194. 1 


322 


241-5 


382 


290.8 


142 


102.8 


203 


149-2 


263 


194.9 


323 


242-3 


383 


291.7 


143 


i°3-5 


204 


150.0 


264 


195-7 


324 


243-1 


384 


292-5 


144 


104-3 


205 


150-7 


265 


196.4 


325 


243-9 


385 


293-4 


145 


105. 1 


206 


151-5 


266 


197.2 


326 


244.6 


386 


294.2 


146 


105-8 


207 


152.2 


267 


198.0 


327 


245-4 


387 


295-1 


147 


106.6 


208 


153-0 


268 


198.8 


328 


246.2 


388 


296.0 


148 


107-3 


209 


153-7 


269 


199-5 


329 


247.0 


389 


296.8 


149 


108. 1 


210 


154-5 


270 


200.3 


330 


247-7 


390 


297-7 


150 


108.8 


211 


155-2 


271 


201. 1 


35^ 


248-5 


391 


298.5 


151 


109.6 


212 


156.0 


272 


201.9 


332 


249-2 


392 


299-4 


152 


110.3 


213 


156-7 


273 


202 -7 


Hi 


250.0 


393 


300.3 


153 


III. I 


214 


157-5 


274 


203-5 


334 


250.8 


394 


301. 1 


154 


III. 9 


215 


158-2 


275 


204-3 


335 


251.6 


395 


302.0 


IS 5 


112. 6 


216 


159-0 


276 


205 -I 


336 


252-5 


396 


302.8 


156 


II3-4 


217 


159-7 


277 


205.9 


337 


253-3 


397 


303.7 


157 


114. 1 


218 


160.4 


278 


206.7 


338 


254 -I 


398 


304.6 


158 


"4-9 


219 


161. 2 


279 


207-5 


339 


254-9 


399 


305.4 


159 


115. 6 


220 


161. 9 


280 


208.3 


340 


255-7 


400 


306.3 


160 


116.4 




1 















* Wiley. Principles and Practice of Agricultural Analysis, Vol. III. pp. 163-165. 



MILK. 

where T is the per cent of total solids, S the lactometer 
reading, and F the fat. An ingenious instrument known 
as Richmond's milk-scale (Fig. 41) is useful in making 
the calculation, instead of employing either the formula or 
a tabic. This is constructed on the principle of the slide 
rule, and by its use the specific gravity may be corrected 
to the proper temperature, and the solids calculated from 
the fat and specific gravity. 

Babcock's formula for solids not fat is as follows : 



Solids not fat = 



looS-FS 



r-) 



(100-^)2.5, 



JOG— I.0753F5 

S being the specific gravity, and F the percentage of 
fat. On this formula he has prepared a table* by means 
of which one may calculate solids not fat agreeing quite 
closely with results obtained by gravimetric analysis. f 
The table on page 118 has been recomputed and enlarged 
from that of Babcock, so as to express results in total 
sohds rather than solids not fat. 

Calculation of Proteids. — Richmond % has devised a 
formula for calculating the proteids from the fat, specific 
gravity, total solids, and ash of milk as follows: 

Q 

p= 2.8r+ 2.5^ -3.33/^-0.7— 

where P represents the proteids, T the total solids, A the 
ash, D the specific gravity, and G the "excess density" 
(=ioooZ) — 1000). The proteids being thus calculated, 
the sugar may be computed by difference. The calcu- 
lation of the proteids in this manner gives at best only 
a rough approximation. 

Determination of Acidity. — While milk is still fresh, 
i.e., before it has begun to undergo lactic fermentation, 
it will show an acid reaction, which is sometimes expressed 
in terms of lactic acid. In view of the fact that 

* U. S. Dept. of Agric, Div of Chem., Bui. 47, p. 123. 

t For approximate work Babcock has suggested the following simpli- 
fied formulas: 

Solids not fat=o.25G-|-o.2F and total solids = o.25G-|- i.2i^, G being 
the lactometer reading and F the fat. 

X Analyst, 15, p. 170. 



OJ 



in 



CD 



^Z> 




o 



00 



CO 



^+ , 



lO 



ii8 



FOOD INSPECTION AND ANALYSIS. 



TABLE SHOWING PER CENT OF TOTAL SOLIDS IN MILK CORRESPONDING 
TO QUEVENNE LACTOMETER READINGS* AND PER CENT OF FAT.f 



Per 

Cent 

of Fat, 



Lactometer Reading at 15.5° C. 



33 



23 



24 



26 



38 



30 



31 



33 



34 



35 



36 



1-3 
1.4 

l-S 
1.6 
1-7 
l.g 
1-9 



5- 

S- 

5 74 

5.86 

5.98 

6. 

6. 22 

6-34 

6.46 

6.58 



5. 75 
5.87 
5 09 
6. II 
6.23 
6.35 
6.47 
6-59 
6.71 
6.83 



6 
6 

6. 34 
6.36 
6.48 
6.60 
6.72 
84 
96 



6.25 
6-37 



6. 

6. 

6. 

7. 

7- 

7 30 

7-42 

7-54 

7.66 

7.78 

7.90 
8.02 
8.14 
8.26 
8.38 
8. so 
8.60 
8.74 
8.86 
8.98 

9.10 
9. 22 



6. 95 

7.07 
7.19 
7-31 
7-43 
7.5s 
7.67 
7-79 
7.91 
8.03 

8.15 
8.27 
8.39 
8.51 
8.63 
8.75 
8.87 
8.90 
9. II 
9-23 



10.06 
10.18 

10.30 
10.42 
10.54 
10. 66 
10,78 



14 
.27 
11.39 

II. 51 
II .63 
II. 75 
II. 87 



12.23 
12-35 
12.47 
12.59 



10.07 

10. 29 
10.31 
10.43 

10. 55 
10.67 
10.79 
10.91 
11.03 
II. IS 
11.27 
1 1 .40 
11.52 

11 . 64 

11.76 
11.88 
12.00 
12.12 

12. 24 
12.36 
1 2 . 4S 
12.60 
12.72 
13.84 



7.08 
7. 20 

7-32 
7.44 
7.56 
7.68 
7.80 
7.92 
8.04 
8.16 
8.38 

8.40 
8.52 
8.64 
8.76 
8.88 
9.00 
9.12 
9.24 
9.36 
9.48 

9. 60 

9.72 
984 
9.96 
10.08 
10. 20 
10.32 
10.44 
10. 5& 
10.68 

10. 80 
10.92 
II .04 

11 . 16 



1 1 .40 
11.52 
II .65 
11.77 
11.89 

12.01 
12.13 
12.25 
12.37 
12.49 
12.61 
12.73 
12. 8s 
12.97 
13.09 



7-45 

7.57 

7.69 

7.81 

7.93 

8.05 

8.17 

8.29 

8.4 

8.53 

8.65 
8.77 



10.93 

II. OS 
II . 17 

11 . 29 
II. 41 
11.53 
11.6s 
11.78 
I I .90 
12.02 

12.14 

12. 26 
12.38 
12.50 
12.62 
12.74 

12.86 
12.98 

13. 10 
13. 22 
13-34 



6.50 
6.63 
6.74 
6.86 
6.98 
7.10 
7.22 
7.34 
7.46 
7.58 

7.70 
7.83 
7.94 
8.06 
8.ig 
8.30 
8.42 
8.54 
8.66 
8.78 

8.90 

9.02 

9.14 

9 . 26 

9.38 

9.50 

9.62 

9.74 

9.86 10. 1 1 

9.98 10.23 



7. 95 

8.07 
8.19 
8.31 
8.43 
8. 55 
8.67 
8.79 
8.91 
9.03 

9.1s 
9.27 
9.39 
9.51 
9.63 
9.75 
9.87 
9.99 



7. 

7.12 

7.24 

7.36 

7.48 

7 ,60 

7.72 

7.84 

7.96 

8,08 

8.30 
8.32 
8.44 
8.s6 
8.68 
8.80 
8.92 
9.04 
9. 16 
9.28 



8.09 
8.21 
8.33 



7 -SO 
7.62 
7,74 
7,86 
7.98 
8.10 
8.22 
8.34 
8.46 
8.58 



8.45 8.70 
8.57 8.82 
8.69' 8.94 



7.75 
7.87 
7.90 
8. II 
8.23 
8.35 
8.47 
8.59 
8.71 
8.83 

8.95 
9.07 



8.81 
8.93 
9-05 
9.17 
9.29 
9-41 
9-53 



10. 10 
10. 22 
10.34 
10.46 
10.58 
10. 70 
10.82 
10.94 
1 1 .06 
II. 18 

11.30 
II .42 
11-54 
11.66 
II .78 
II .90 
12.03 

12.15 

12.27 
12.39 

12.51 
12.63 
12.75 
12.87 
12.99 
13. II 
13.23 
13.3s 
13.47 
13.59 



9.6s 9.90 
9.77 10.02 
9.89 10.14 
10.01 10. 26 
10.13 10.38 
10. 25 10. 50 
10. 37|io.62 
10 . 49' 10 . 74 
10.61 10.86 
10.73 10.98 



10.35 
10.47 
10. 59 
10.71 
10.83 
10.95 
11.08 
1 1 . 20 
11.32 
11.44 

11.56 
11.68 
11.80 
11.92 
I 2.04 
12.16 
12.28 

13 .40 
13.52 
12-64 

12.76 

12.88 
13.00 

13. 12 
13.24 
13-36 
13.48 
13.60 
13.72 
13.84 



IO.60IIO.85 

10. 72;io.97 
io.84'i T -09 

10. 96,11 . 22 
II .09 11.34 

1 1 . 2 1 1 1 . 46 



.33'ii. 
■ 45 II- 
.57 II- 
,69 11-94 



1 1 .81 12, 
II .93 12, 
12 .05 12, 
12.17 12, 

I 2 . 29 13, 

12.41^12 
12.53 12 
I2.65I12 

I2.77II3 
12.89:13, 



13.26 
13. 38 
13.50 
13.62 
13.71 
13-86 
13-99 

14- 1 1 
14-22 
14-35 



6.0 12.71 12.96 13.31 13-46 13.71 13-96 14.22 14-47 14.72 14-98 15-23 15.48 l5-73|lS-98 16-24 



II - 10 
11-23 





47 




5Q 




71 




83 




95 




07 


13 


19 


12 


31 


12 


43 


12 


5 5 


12 


67 


12 


79 


12 


91 


13 


03 


13 


15 


13 


37 


13 


39 



9-67 

9.79 

9-91 

10.03 

o.iS 

0. 37 

0.30 

0.5 

0.63 

0.75 

0.87 

0.99 

1 . 1 1 

1-23 
1-36 

I -48 

1 . 60 

I -72 
1.84 

I - 96 



13-51 
13-63 
13-75 
13-87 

14.00 
14.12 

14.24 
14.36 
14.48 

14. 60 



3 

3 

3 

3.40 

3.52 

3.64 

3.76 
3.89 
4.01 
13 
25 
37 
49 
61 
74 
86 



8. 24 
8.36 
8.48 
8.60 
8.72 
8.84 
8.96 
9.08 



0.04 
o. 16 
0.28 

0.40 
0.52 
0.64 
0.76 
0.88 



1.24 
1-37 
1-49 

I. 61 
1-73 
l-8s 
1-97 
2 .09 
2.21 
2.33 
2.45 
2. 57 
2.69 

2.8l 

93 

■ 05 
iS 
30 
42 

■ 54 
,66 

■ 78 

■ 90 



4.02 
4.14 



8.25 

8.37 

8.49 

8.61 

8.73 

8.8s 

8.97 

9.09 

9. 

9.33 



8.50 

8.62 

8.74 

8.86 

8.99 

9- 

9. 

9. 

9. 

9- 



9-45 

9-57 
9-69 
9-81 
9-93 
0.05 
0-17 

0, 29 
0-41 
0-S5 

0-66 
0.78 
0.90 

1 . 02 
1. 14 
1 . 26 
1.38 
1-50 
1 . 62 
1.74 

1.86 
I. 98 



9.70 
9.82 
9.94 
10. 06 
10. 18 
10.30 
10.42 
'O.S4 
10. 66 
10. 7 

10.9 

11.03 

II. 15 

11.27 

11.39 

II. 51 

11.63 

11.75 

11.87 

11 .99 

13.11 
13.23 
13.35 
12.48 

12 . 60 
12.72 
12.84 
I 2 . 96 
13.0, 
13. 20 

13.32 
13.44 
13.56 
13.68 
13.80 
13.93 
14.04 
14.16 
14.28 
14.40 



8-75 
8.87 
8-99 
9. II 
9-23 
9-35 
9-47 
9-59 
9.71 
9.83 

9-95 

10.07 
10. 19 
10.31 
10.43 
10. 55 
10.67 
10.79 
10.91 
II .04 

11.16 
11.38 
1 1 .40 
11.52 
II . 64 
II .76 
11.88 

13 .00 
13.12 
13. 34 

13.35' 
12.48 



12 
12 


6I] 

73 


12 


85! 


12 


97 


13 


09 


13 


21 


13 


33 


13 
11 


45 
57 



13.69 
13.82 
13.94 

14.06 
14. iS 

14-30 
14-43 
14-54 
14-66 



145- 14, 
14.04 14 

14.70 IS, 

14.88 15, 

15.01 IS 

15-13 15, 
15-25 15, 

15-37115, 
15-49 15, 
lS-61 15. 



9-00 
9-1 • 
9-24 
9-36 
9-48 
9 -60 
9-72 
9.84 
9.96 



0.20 

0.32 
0.44 

0. s6 
0.68 
0.80 
0.93 
1 .04 
1. 17 

1 . 39 

1. 41 
1.53 
1.65 
1.77 
1.89 
2.01 
2.13 

2.35 

2-37 
2-49 

3- 61 

2-74 
2.86 
3.98 
3.10 
3.33 
3.34 
3.46 
3.58 
3 70 

3.83 
3.95 
4.07 
4.19 
4.31 
4.43 
4.55 
4.67 
4.79 
4-91 



■ 03 
-15 
.37 
-39 

-SI 
-63 
.75 
-87 
-99 
16.13 



*The lactometer reading is expressed in whole numbers for convenience. The true specific gravity 
corresponding to a given lactometer reading is obtained by writing 1,0 before the lactoimeter reading. 
Thus, 1.026 is the specific gravity corresponding to lactometer reading 26, etc. 

t An. Rep. Mass. State Board of Health, 1901, p. 445. (Analyst's Reprint, p. 25.) 



MILK. 119 

the acidity of "sweet" milk is due partly to the presence of acid phos- 
phates and partly to dissolved carbonic acid in the milk, and not to lactic 
acid, which is probably absent, a better plan is to express the acidity in 
terms of the number of cubic centimeters of tenth-normal alkali necessary 
to neutralize a given quantity of the milk, either 25 or 50 cc, using phenol- 
phthalein as an indicator. 

If it is desired to calculate the acidity in terms of lactic acid, multiply 
the number of cubic centimeters of tenth-normal alkali used by 0.897, and 
divide by the number of cubic centimeters of milk titrated, the result 
being the percentage of lactic acid. 

Detection of Boiled Milk. — Dupouy's Method. — Five cc. of milk are 
added to a few drops of a freshly prepared solution of diamidobenzene 
in water (1:4), and a little hydrogen dioxide is added. With raw milk a 
blue coloration will be apparent, while with milk that has been heated to 
79° or over no color is produced. 

MODIFIED MILK. 

A comparison of the composition of cow's milk and human milk, as 
in the following table by Dr. Emmett Holt, * shows very marked differ- 
ences. 

Woman's Milk, Cow's Milk, 

Average. Average. 

Fat 4-00 3.50 

Sugar 7.00 4.30 

Proteids 1.50 4.00 

Ash 0.20 0.70 

Water 87 . 30 87 . 50 

The per cent of fat in the two kinds of milk is nearly the same. There 
is, however, too little sugar and an excess of proteids and ash in the milk 
of the cow, assuming human milk as the ideal infant food, so that in 
basing a diet for infants on the basis of human milk considerable modi- 
fication is necessar)'. Moreover, aside from the actual variation in the 
amount of ingredients, there are certain inherent differences in the 
character of the same ingredient, as found in the milk of the cow and in 
human milk. The proteids of cow's milk are, for instance, found to be 
much more difficult of digestion than those of woman's milk, and the 
same is probably true of the fat. Aside from the mere statement of a 

* "Infancy and Childhcod." 



I20 FOOD INSPECTION AND ANALYSIS. 

few of these differences, it is obviously beyond the scope of this work to 
discuss this phase of the subject in detail, reference being made, how- 
ever, to such books as Dr. T. M. Rotch's "Pediatrics," and "Infancy 
and Childhood" by Dr. Emmett Holt, for full particulars. So great 
has been the demand by physicians for "modified milk" for infant 
feeding, that laboratories for this exclusive purpose have been established 
in many of the larger cities, in which not only is milk prepared in 
accordance with certain fixed formulae supposed to be adapted to average 
infants of varying age, but milk of any desired composition is prepared, 
in accordance with special prescriptions of physicians to apply to indi- 
vidual cases. 

Methods and Ingredients. — The proteids and the ash in cow's milk 
are much higher than in human milk, and both are brought to the proper 
degree of reduction by diluting the milk with water. Milk sugar is 
increased by the addition of lactose, and the fat is increased or diminished 
by addition of cream or by skimming. 

The dilution of cow's milk with a measured amount of water shows 
the following results on the proteids and ash: 



Cow's Milk. 


Diluted 
Once. 


Diluted 
Twice. 


Diluted 
Three Times. 


Diluted 
Four Times. 


Proteids 


Per cent. 
4.00 
0.70 


Per cent. 
2.00 

°-35 


Per cent. 

1-33 
0.23 


Per cent. 
1.00 
0.18 


Per cent. 
80 


Ash 


0.14 





The ingredients commonly employed for modifying milk are (i) cream, 
containing 'i.(f/i_, of fat, (2) centrifugally skimmed milk, otherwise known 
as "separator milk" from which the fat has been removed, (3) milk 
sugar, or a standard solution of milk sugar of, say, 20% strength, and 
(4) lime water. Unusual care should be taken in the selection of the 
milk supply to insure cleanness, purity, and freshness, as well as in the 
care of utensils, etc., used in the laboratory, which should in all cases 
be scrupulously clean. Samples prepared in accordance with a given 
formula or formula; are pasteurized in separate bottles, or, if desired, 
sterilized, and after stoppering with cotton are kept on ice. 

Formula. — It is obviously impossible to establish formulae univer- 
sally applicable even to healthy infants, but the following may be 
regarded as typical formulas, representing the composition of modified 
milk to suit the needs of an average growing infant during its first 
year: 



MILK. 



Period. 


Fat. 


Proteids. 


Sugar. 


Third to fourteenth day 

Second to sixth week 


Per cent. 
2 

2-5 

3 

3-5 

4 


Per cent. 
0.6 

0.8 
I.o 

1-5 

2 
2-5 


Per cent. 
6 
6 
6 
7 
7 
3-5 


Sixth to eleventh week 

Eleventh week to fifth month. . 

Fifth to ninth month 

Ninth to twelfth month 



Milk according to the above formulae can 
be very simply prepared by the aid of a spe- 
cially made graduate known as the "Materna" 

and shown in Fig. 42. 

PREPARED MILK FOODS. 

Milk Powder. — There are numerous brands 
of desiccated milk or milk powder on the 
market, sold in bulk and by the can, and largely 
used by bakers. Many of these purport to 
contain all the ingredients of milk excepting 
water, but no samples of desiccated whole milk 
have yet come under the notice of the writer. 
All the available brands examined by him have 
proved to be pulverized dried skimmed milk, 
having a composition of which the following is 
typical : 

Moisture 

Fat 

Proteids (NX 6.25) 

Milk sugar 

Ash 




Fig. 42. — The "Materna" 
Graduate for Modifying 
Milk. 



8.16 

1-73 
33-84 

49-35 
6.87 



99-95 
This corresponds to about 0.16% fat in the original milk. 
Artificial Albuminous Foods. — The albumin and casein of milk have 
furnished the basis of a variety of food preparations, some of which are 
intended for the use of invalids and people of weak digestion, and others, 
from their compactness, for travellers and campers. Among these foods 
are the following: 

Nutrose This is a caseinate of sodium formed by the action of the 
alkali upon dried casein. It is soluble in water. 



122 



FOOD INSPECTION /tND /IN/I LYSIS. 



Eucasin is a caseinate of ammonium, a soluble powder somewhat 
similar to nutrose. 

Plasmon. — This is a yellowish powder, prepared by treatment with 
sodium bicarbonate of the curd precipitated from skimmed milk. The 
compound is kneaded in an atmosphere of carbon dioxide, and reduced 
to a soluble powder. 

The following analysis of plasmon was made by Woods and Merrill:* 



Water. 


Proteids. 


Fat. 


Carbohydrates. 


Ash. ' Fuel Value. 


8-5 


75-0 


0.2 


8.9 


7-4 


2044 



Sanose. — This is also a powder, containing 80% of pure casein and 
20% of albumose, obtained from the white of egg. The powder possesses 
a slight taste and an odor suggestive of milk. By briskly stirring the powder 
with water, an emulsion may be made much resembling milk, but on 
standing it soon breaks up. 

Sanatogen is a grayish-white, tasteless powder, containing 95% of 
casein and 5% sodium glycero-phosphate. When treated with cold 
water it swells, forming on heating a milk-like emulsion. 

Kovunis is a stimulating beverage, prepared by allowing milk to undergo 
alcoholic, lactic, and proteolytic fermentations. The original koumis 
was made by the Tartar tribes of Asia from mare's milk, which contains 
more lactose than cow's milk, and apparently lends itself more readily 
to fermentation. Only a hmited amount of koumis is now made from 
mare's milk, the milk chiefly used for this preparation being that of the 
cow, treated with yeast and sometimes added sugar. Koumis is a 
beverage much more commonly used in Europe than in America. 

The following analyses were made by Vieth : | 



Mare's milk. . . 
Cow's milk. . . 
Skimmed milk 



Water. 



Alco- 
hol. 



Fat. 



92.07 2.98 1.30 
90.57 1.04 1.38 
92-52 0.57 0.33 



Casein. 



0.83 
1.88 
2.03 



Albu- 
min. 



0.24 
0.20 
0.07 



Albu- 
min- 
oses. 



0.77 
0.77 
0.63 



Lactic 
Acid. 



1.27 
1.40 
0.56 



Sugar. 



0.23 
2.18 
2-45 



Ash. 



0-35 
0.58 
0.84 



Kephir. — This is a fermented milk product similar to koumis, excepting 
that the fermentation is induced by a fungus known as kephir grains. 

* Maine E.xp. Station, Bulletin 178, p. loi. 
t Richmond, Dairy Chemistry, p. 241 et seq. 



MILK. 



123 



The proteolytic fermentation is less pronounced in kephir than in koumis. 
Konig gives the following table as the mean of twenty-eight analyses: 



Water. 


N tro- 
gen. 


1 Aiu ' Acid 

Casein. •^^"- i Albu- 

"""• ' min. 


Hemi- Pep- p^ 
albumin.! tone. 1 


Lac- Lactic 
lose. Acid. 


Alco- 
hol. 


Ash. 


91.21 


3-49 


2-53 0-36 0-21 


0.21 


0-039 ' 1-44 


2.41 1 1.02 


0-75 


0.68 



ADULTERATION OF MILK. 

Systems of Milk Inspection. — A typical method of general food inspec- 
tion has already been outlined (see pp. 5 and 6), which may easily be modi- 
fied to include the inspection of milk in connection with other foods, or to 
provide for a system of milk inspection exclusively. In the examination 
of such a perishable food as milk, it has not been found practicable for 
the analyst to reserve for the benefit of the defendant a sealed sample, 
as in the case of other foods, but experience has shown it had best be made 
the duty of the collector or inspector to give a sealed sample of milk to 
the dealer, when the latter requests it at the time of taking the sample. 
For this purpose the collector is provided with small bottles and seahng 
pharaphernalia, in addition to the tagged sample bottles or cans in which 
he collects the milk. The collector should use the same precautions 
for obtaining a perfectly fair representative sample as does the chemist 
in making the analysis, i.e., he should carefully pour the milk from the 
original container into an empty can or vessel and back again, before 
taking his sample. 

Each sample is properly numbered by the collector in presence of the 
dealer, and the data as to the taking of the sample entered at once under 
the proper number in the collector's book. If a sealed sample is given, 
it should bear the same number as the sample reser\'ed for analysis, and 
a receipt should invariably be required from the dealer, as evidence that 
his request for a scaled sample has been compHed with. 

Milk Standards Fixed by Law. — In locahties where a systematic form 
of milk inspection prevails, there is usually in force a statute fixing the 
legal standard for the total solids, and in many cases for the fat or for 
the sohds exclusive of fat. In some states the statute is so drawn that 
any deviation from the legal standard constitutes an adulteration in the 
eye of the law, and hence the offender, who has such milk in his possession 
with intent to sell, is liable to the same fine as if he actually added water 
or a foreign substance to the milk. 



124 FOOD INSPECTION AND ANALYSIS. 

In Other states a distinction is made by the statute between milk that 
is simply below the legal standard of total solids, and milk containing 
actually added ingredients (water or otherwise), a much lighter fine being 
imposed for the former than for the latter offense. Where such a dis- 
tinction prevails, it often becomes incumbent upon the analyst to show 
to the satisfaction of the court, in case of milk low in solids, whether or 
not the milk has been fraudulently watered after being drawn from the 
cow, it being well understood that cows may give milk below the standard. 

Pure milk that is low in solids may owe its deficiency either to poor 
feeding, or to an inherent tendency on the part of the cow to give milk 
always of poor quahty. Thus the Holstein cow, more than any other 
breed, is open to the charge of sometimes giving milk below the standard.* 
That the Holstein cow is a favorite with the producer is by no means 
strange, from the fact that no other breed can with moderate feeding 
be made to give so large a quantity of milk. 

Wherever there is a statute fixing the standard for milk, it commonly 
provides also that the addition of any foreign substance whatsoever con- 
stitutes an adulteration, and is not to be countenanced, in spite of the open 
question as to whether or not antiseptic substances, much used as pre- 
servatives, are or are not harmful. 

U. S. Standards.! — Standard milk is milk containing not less than 
12% of total solids, and not less than 8.5% of solids not fat, nor less than 
3.25% of milk-fat. 

Standard Skim-milk is skim-milk containing not less than 9.25% of 
milk solids. 

FORMS OF ADULTERATION. — Milk is ordinarily aduherated (i) by 
watering, (2) by skimming, (3) by both watering and skimming, and 
(4) by the addition of on • or more foreign ingredients. 

Watering and Skimming. — The fact that milk is found below the 
standard of total solids, while more often due to an excess of water, may 
also be due to a deficiency in fat. In one case the milk is commonly 

* This statement should not be taken as condemning the Holstein, for it is true that cows 
of this breed often give milk far above the standard. A large number of samples of milk 
of known purity from Holsteins analyzed by the writer have been found to be of excellent 
quality. It is a curious fact that among the samples of known purity analyzed by the Massa- 
chusetts Board of Health, both the lowest and highest total solids on record came from a 
Holstein cow; the lowest recorded total solids in a "known purity" milk being 9.96 per 
cent, (seventh annual report of Massachusetts State Board of Health, Lunacy, and Charity, 
p. 160), and the highest being 17.06 per cent, (twenty-second annual report of the Massa. 
chusetts State Board of Health, p. 405). 

fU. S. Dept. of Agric, Off. of Sec, Circ. 10. 



MILK. 125 

termed watered, and in the other skimmed, using the terms broadly and 
not necessarily meaning actual and fraudulent tampering with the milk. 
In a third case, and almost invariably fraudulently, both watering and 
skimming may be found to have been practiced on the same sample. 
The analyst judges which of these causes have produced a milk low in 
solids, by a careful study of the relation between the percentages of total 
solids, fat, and solids not fat. 

If both the total solids and solids not fat arc abnormally low, and 
the proportion of fat to solids not fat about the same as, or higher than, 
in a normal milk, it is generally safe to assume that the sample has been 
watered; if both the total solids and the fat are well below the standard, 
and the solids not fat nearly normal, then the milk has undoubtedly been 
skimmed; if, in the third place, the total solids and the solids not fat are 
proportionally reduced below the standard, while the ratio of fat to solids 
not fat is abnormally small, it is safe to adjudge the milk to be low by 
reason of both skimming and watering. 

Milk of Known Purity. — It is difficult to place the minimum figure 
for total solids, below which a milk sample may safely be pronounced 
by the analyst as fraudulently watered after having been drawn from 
the cow. Nearly nine hundred samples of milk of known purity from 
various breeds of cow, milked in the presence of an inspector, have been 
analyzed in the Department of Food and Drug Inspection of the Massa- 
chusetts State Board of Health, extending over a period of fifteen years, 
and among these are many samples from Holstein cows. It is extremely 
rare that any of these known purity samples have been found with total 
soUds as low as 11%, though there are instances where total solids have 
run as low as 10%. 

It is safe to assume that in the few cases on record showing less than 
10.75% of ^°'^^ solids, either there was something decidedly abnormal 
about the health of the cow, or, through some accident, the cow was only 
partially milked, it being a well-known fact that the last fraction of the 
milking includes the larger percentage of fat. (See page 92.) 

It is therefore nearly always safe to condemn a milk standing below 
10.75 S-s fraudulently watered, if at the same time it has a proportionately 
high per cent of fat. 

The average total solids of 800 samples of milk of known purity analyzed 
by the Massachusetts Board up to and including the year 1890 amounted 
to about 131%. 

It is rare indeed to find a herd of ten or more well-fed cows of mixed 



126 



FOOD INSPECTION AND ANALYSIS. 



breeds in which the average milk of the herd falls below 12^% of solids. 

The milk of forty-seven Holstein cows, examined in 1885, was found to 
contain an average of 12.51% of total solids, while the milk of eleven 
Jerseys examined in the same year averaged 14.02% of solids. These 
examples represent the two extremes commonly met with. 

Variation in Standard. — In Massachusetts the law fixes a different 
standard for total solids in milk during the summer, or pasture-fed season, 
from that in force during the winter, or stall-fed period. From April 
to September inclusive the legal standard is 12% of total solids, of which 
9% are solids not fat, and from October to March inclusive it is 13%, of 
which 9.3% are solids not fat. Bearing on the question of difference in 
normal quality of milk during the two periods, averages were taken of the 
milks collected by the corps of inspectors of the Massachusetts Board of 
Health during a month in each period, December and June being selected 
as most typical, and during these months all the samples were analyzed 
both for total solids and fat. The samples were taken from stores, milkmen, 
and producers, and represented as nearly as possible the milk as actually 
sold to the consumers. In making the averages, all samples of skimmed 
milk, as well as all samples standing above 17% of total soHds, or under 
10.75%, ^^T^^ deducted. The results are summarized as follows: 

QUALITY OF MILK SOLD IN MASSACHUSETTS CITIES AND TOWNS IN 

WINTER AND SUMMER. 





December. 




Number 

of 
Samples. 


Total Solids. 


Fat. 


Solids 




Highest 
Per Cent. 


Lowest 
Per Cent. 


Average 
Per Cent. 


Highest 
Per Cent. 


Lowest 
Per Cent. 


Average 
Per Cent. 


Average 
Per Cent. 


Cities 

Towns 

Summary .... 


403 

99 

502 


16.86 
15-48 
16.86 


10. 88 
12.02 
10.88 


13.21 
13-44 
13-32 


8.50 
6.65 
8-50 


2.40 
3-50 
2.40 


4.37 
4.48 
4.42 


8.74 
8.96 
8.85 






June. 




Number 

of 
Samples. 


Total Solids. 


Fat. 


Solids 




Highest 
Per Cent. 


Lowest 
Per Cent. 


Average 
Per Cent. 


Highest 
Per Cent. 


Lowest 
Per Cent. 


Average 
Per Cent. 


Average 
Per Cent. 


Cities 

Towns 

Summary .... 


3" 
76 

387 


16.90 

15-71 
16.90 


10-75 
10.99 

10-75 


12.67 
12.63 
12.65 


8.80 
7.10 
8.80 


2.10 
3.00 

2.10 


4-03 
4-09 
4.06 


8.54 

8.S4 
8.S4 



It is interesting to note that the average for total solids of the 889 



MILK. 127 

samples examined for both months stands at just 13%, of which 4.24% is 
fat and 8.76 is solids not fat. 

Rapid Approximate Methods of Determining the Quality of Milk. — 

The Lactometer.- — A rough idea of the quality of milk can be gained by the 
use of the lactometer (page 95), but, in view of the fact that a low specific 
gravity may be the result either of a watered milk or of a milk high in fat, 
good judgment is necessary' in connection with its use. A milk of good 
standard quality should have a specific gravity between the limits of 
1.027 and 1.033. A watered milk would run below the former and a 
skimmed milk above the latter figure, though a milk unusually rich in fat 
would also nm low. It should easily be apparent from the taste and appear- 
ance of the milk, whether a low specific gravity is due to watering or 
unusual richness in fat. The fact should also be recognized, that a milk 
sample may be far below the standard, and still show a specific gravity 
within the limits of pure milk, by skillfully subjecting the milk to both 
skimming and watering. 

The Lactoscope. — Feser's lactoscope (Fig. 43) gives an approximation to 
the amount of fat in milk, and its use, especially' in connection with the 
lactometer, is of some value. This instrument consists of a graduated glass 
barrel, a, into the bottom of which is accurately fitted the stopper, bearing 
a white glass cylinder, having black lines thereon. Four cc. of milk are 
introduced into the barrel by means of a pipette, c, and water is added 
with thorough mixing till the translucence of the mixture is sufficient to 
allow the black lines to be perceptible through it. The height of the level 
of milk and water in the barrel a is then read off, the number indicating 
roughly the percentage of fat in the sample. 

As in the case of the lactometer, the purity of a milk sample cannot 
be positively established by the lactoscope alone. For instance, a watered 
milk abnormally high in fat would often be found to read within the limits 
of pure milk, when as a matter of fact its total solids would be below stand- 
ard. By a careful comparison of the readings of both the lactoscope and 
lactometer, however, it is rare that a skimmed or watered sample could 
escape detection. 

Thus, if the specific gravity by the lactometer is well within the limits 
of pure milk, and the fat, as shown by the lactoscope, is above 3J per 
cent., the sample may be safely passed as pure, or as conforming to the 
standard. 

A normal lactometer reading in connection with an abnormally low 
lactoscope reading shows both watering and skimming, and with an 



128 



FOOD INSPECTION /IND ANALYSIS. 



abnormally high lactoscope reading shows a milk high in fat, or a cream. 
With the lactoscope reading below three, and a low lactometer reading, 




V-f 



m 



■m. 



\A M 



Fig. 43. — Feser's Lactoscope. 



watering is indicated. A lactometer reading above thirty-three, and a low 
lactoscope reading, indicate skimming. 

Heeren's Pioscopc. — This instrument consists of a hard-rubber disk, 



MILK. 129 

having in the center a shallow receptacle, the circular rim of which is raised 
above the level of the disk. Into this receptacle arc introduced a few 
drops of the milk to be tested, and a circular cover-glass containing a 
number of variously tinted segments is placed over the receptacle, which 
spreads the milk out into a thin layer, and causes it to assume a tint against 
the black background that can be matched with one of the colors on the 
glass, the various tints indicating milks of various grades from the very 
poorest to rich cream. This test is at best a very rough one. 

Examination of the Milk Serum. — Specific Gravity. — It has been pro- 
posed to calculate the amount of added water in milk from the specilic 
gravity of the milk serum, since it has been found that under fixed con- 
ditions the composition of the milk serum, or clear "whey," is more 
constant than that of the milk itself. Hence any considerable amount 
of watering is manifest from the specific gravity of the serum. 

In using this method the analyst should carefully work out his own 
standards for comparison, by personal experiment on milk of known 
composition to which varying amounts of water have been added, using 
the same conditions for obtaining the serum in all cases. Woodman's 
method * is as follows: To 100 cc. of the milk at a temperature of about 
20° C. are added 2 cc. of 25% acetic acid, specific gravity 1.0350, in a 
beaker, and the beaker, covered with a watch-glass, is heated in a water- 
bath for 20 minutes at a temperature of 70° C. After this the beaker is 
placed in ice water for 10 minutes and the solution filtered. The specific 
gravity of the clear filtrate is taken at 15° C. with the Westphal balance. 

In the Appendix will be found a table showing the specific gravity of 
the serum of milk containing varying degrees of added water, as well as 
that of the serum of a wide variety of whole milks. 

Immersion Rejractomeler. — In the Appendix a method is given for de- 
tecting added water in milk by an examination of the serum with the 
Zeiss immersion refractometer. 

Systematic Examination of Milk for Adulteration. — If a large number 
of samples of milk have to be examined daily for adulteration, it may be 
an advantage to submit all to a preliminary test with the lactoscope and 
lactometer, excluding from further analysis, as above the standard, such 
samples as pass certain prescribed limits which experience has proved 
these tests to be capable of showing to an experienced observer, and 
submitting the remainder to a chemical analysis. In using such an instru- 
ment as the lactoscope for this purpose, the individual element is a most 

* Jour. .\m. CItcm. Soc, 21 (1899), p. 503. 




I30 FOOD INSPECTION /IND ANALYSIS. 

important consideration, and the use of this instrument in the milk labora- 
tory should be limited only to a skillful operator, accustomed to interpret 
its results. 

The method used in the writer's laboratory has been to submit all 
samples to the regular test for solids, and such samples as fall below 
the legal standard for solids, are further examined for fat. 

Total Solids, Fat, and Ash. — It is presupposed that the analyst is 
equipped with a sufficient number of platinum dishes for the number 
of milk samples daily analyzed. It is a convenience to have these dishes 
numbered, and instead of weighing each dish, to have a system of numbered 
counterweights (Fig. 44) corresponding to the dishes. The counterweights 
in use by the author for this purpose are easily 
made from half-inch lead pipe, cut to the appro- 
priate length and flattened. Each weight is then 
carefully adjusted to its appropriate dish, by 
trimming off the weight with a knife, or by adding 
bits of lead scraps, if necessary, by simply prying 
Fig —Lead Counter °P^'^ '^ ^^^ Center, inserting the required amount of 
weight for Platinum scrap, and then closing by a blow of the hammer. 
Dish. Made from the weight being plainly numbered before final 
half -inch lead pipe adjustment. A rack is provided by the side of 

flattened. ■' J ■ , ,- r i i i- 

the balance-case (Fig. 45) with suts for holding 
the weights in their appropriate places. Such a set of counterweights 
is not difficult to make, requires very little care to keep in adjustment, 
and is an immense labor-saving device. 

Details oj Manipulation. — The following method of examining large 
numbers of milk samples is the one in use in the laboratory of the Massa- 
chusetts State Board of Health and is given in some detail, as long exper- 
ience has proved it to be rapid, easy, and accurate. 

From 12 to 20 samples of milk are conveniently weighed out at a 
sitting, the unopened sample cans or bottles being contained in a tray 
at the left of the operator on a low stand, another low stand and tray 
being at his right hand for the cans, after removing the weighed portions, 
and a third tray on the table at the right of the balance for the platinum 
dishes with the weighed samples. The analyst enters the number of 
the platinum dish in his note-book, or on a card,* in line with the number 
of the milk sample, verifies the correctness of the counterweight, and 
weighs out exactly 5 grams of the milk with the aid of a pipette, after 

* Specially ruled library cards as shown in Fig. 46 are useful for this purpose. 



MILK. 



first having thoroughly mixed the sample. This operation is repeated 
with all the samples, the platinum dishes containing the weighed amounts 
of each being placed in succession on the tray, which is finally carried to 
the water-bath and the dishes transferred thereto. The time required 
for weighing out 1 2 samples of milk in this manner is about fifteen minutes. 
The water-bath is inclosed in a hood, and the sliding front is so arranged 
that it can be shut down and locked, so that if the analyst has to leave 




Fig. 45. — Set of Counterweights for Numbered Platinum Dishes, in a Convenient Rack. 

the laboratory during the three hours required for the evaporation, he 
can swear in court that the samples could not be tampered with during 
his absence (see page 19). 

WTien ready to make the second weighings for the total solids, each 
dish is taken from contact with the steam, and, while still hot, is wiped 
dry with a soft towel, till tv/clve of the dishes are placed on the tray, 
which is then taken to the balance. Experience has shown that with 
ordinary rapidity in weighing, twelve of the residues may be thus dealt 
with at a time without the need of a desiccator, the gathering of moisture 
during that time being inappreciable, excepting in very damp weather, 
when a less number of dishes should be removed at a time from the bath. 
In making the second weighing, and employing the counterweight as 



132 




FOOD 


INSPECTION AND ANALYSIS. 








Vaie . . 

< 


Mu*^^u.(tJt 


*f6 


/fOV 






Inspector's 
Number. 


No. of 
Diih 


.y Gra.rr\S' 


Total 
Solids. 


No of 
Botue 


Fat 


Solids Y\ot 
-Tat 


■Remarhr 


! z(><fZf 


/ 


.6'r6~S' 


IZ.9] 










16^^ 




i>6-3 


I3.0(> 










2.feV6 


,? 


(.Oil 


i7j.0Z 










1(,^? 


V 


r<^8d 


II .9 G 


5 


3 2.6' 


!(.7) 




3.G6-0 


yf 


72.6? 


J^S3 










dbfZ 


(> 


An*, 


;i.36' 


^ 


Z.SO 


.T^S 


A.t.».aaaa>. 


Z06'^ 


7 


.(>gZ3 


I3.GS 










2(,S'C 


,? 


.6301 


IZ.(,0 










2.6 .ri? 


9 


.69Z^ 


/3.9J' 










2(,i>0 


10 


hiss 


I2.Z1 










X.662 


II 


.KS9S- 


9./9 


S 


0.1 s 


9.0*1 




a.664 


IZ 


^^93 


9.39 


^ 


cL^tr 


6.6*1 




26U 


/^ 


GS-30 


I3.6C 










X(>(>8 


1^1 


hlhSQ, 


Zii.90 










IhlO 


n' 


A 2 9.? 


n..S9 










0LI.1X 


1^ 


7393 


/A. 19 








JbOM^ 


ILl^ 


11 


.110% 


li^.ZCl 










lUlL 


1^ 


(,010 


)X.62 










1.L1E 


/9 


. ^.<ro 1 


9.00 


7 


I.ZO 


1 .80 




2.hgO 


ZO 


. GS-31 


J3.0G 




























































































































1 













Fig. 46. — Specimen Card for .Analyst's Records of Milk Analyses. To be filed in a cabinet. 



MILK. 



133 



before, the exact net weight of the residue is at once ascertained and 
entered in the appropriate column in the note-book. Multiphed by 
20 it gives at once the percentage of total solids. 

It is a great saving of time to weigh out exactly 5 grams as above 
described. The knack of quickly measuring out the exact amount is easily 
acquired with practice, the 5-gram weight is the only one required for 
the operation with the counterweight of the dish, and the laborious figuring 
of percentage due to using a fraction above or below the 5 grams of milk 
is avoided. 

Such samples as are found to stand below the standard of total solids 
are further examined for fat by the Babcock process (p. 100), entering 
the number of the fat bottle in the note-book in the appropriate column, 
and subsequently the percentage of fat. 

Ordinarily the specific gravity is not determined, excepting in some 
cases of badly watered milk, when, for purposes of a check, it is customar)- 
to take the specific gravity, and calculate the solids from the gravity and 
the fat by Babcock's formula (p. 89), or the Richmond sUding scale, and 
compare the result with the figure directly determined. 

The ash is rarely weighed except in special cases. 

The dishes containing the dry residues are easily cleaned by first 
burning to an ash and coohng, after which they are treated successively 
with strong nitric acid, which is poured from one to another, the dishes 
being rinsed thoroughly with water and finally heated to redness. 

A convenient device for ashing a large number of residues for purposes 
of cleaning the platinum dishes and for final heating is the incinerator 
shown in Fig. 47, made of Russia iron. 



£k>^ 




Fig. 47. — \ Sheet-metal Incinerator, Specially Useful for Ashing Milk Residues. 



ADDED FOREIGN INGREDIENTS. 



Passing over such mythical and impossible adulterants as chalk, and 
the almost as rarely used substances calves' brains, starch, glycerin, 



134 FOOD INSPECTION AND ANALYSIS. 

sugar, etc., often discussed in manuals on milk, but with few authentic 
instances of their actual occurrence, the commonly found adulterants 
may be divided into two classes: coloring matters and presen'atives. 

The coloring matters almost exclusively used are annatto, azo-colors, 
and caramel. The preservatives commonly met with are formaldehyde, 
boric acid, borax, and sodium bicarbonate. Rarely salicylic and benzoic 
acids are found. 

Coloring Matters. — While it is more often true that an artificially 
colored milk is also found to be watered, the coloring being added to 
cover up evidence of the watering, it is not uncommon to find added 
coloring matter in milk above the standard.* 

About 95% of the milks found colored in Massachusetts show on 
analysis the fraudulent addition of water. 

Statistics of the Massachusetts State Board of Health show that out 
of 48,000 samples of milk collected throughout the state and analyzed 
during nine years (from 1894 to 1902 inclusive) 342 samples or 0.7% 
were found to contain foreign coloring matter. Of these samples, about 
67% contained annatto, approximately 30% were found with an azo- 
dye, and about 3% with caramel. 

Until comparatively recently annatto was employed almost exclu- 
sively for this purpose. Caramel is least desirable of all the above colors 
from the point of view of the milk-dealer, in that it is difficult to imitate 
with it the natural color of milk, by reason of the fact that the caramel 
color has too much of the brown and too little of the yellow in its com- 
position. Annatto, on the other hand, when judiciously used and with 
the right dilution, gives a very rich, creamy appearance to the milk, even 
when watered, which accounts for its popularity as a milk adulterant. 
Of late, however, the use of one or more of the azo-dyes has been on 
the increase, and so far as a close imitation of the cream color is con- 
cerned, these colors are quite as efficient as annatto. 

Appearance of Artificially Colored Milk.^The natural yellow color 
of milk confines itself largely to the cream. An artificial color, on the 
contrary, is dissipated through the whole body of the milk, so that when 
the cream has risen in a milk thus colored, the underlying layers, instead 
of showing the familiar bluish tint of skimmed milk, are still distinctly 
tinged below the layer of the fat, especially if any considerable quantity 
of the color has been used. This distinctive appearance is in itself often 

* In one instance an azo-dye was found by the writer in a milk that contained over 
17% of total solids. 



MILK. I3S 

sufficient to direct the attention of the analyst to an artificially colored 
milk, in the course of handling a large number of samples. 

Nature of Annatto. — Annatto, arnatto, or annotto is a reddish-yellow 
coloring matter, derived from the pulp inclosing the seeds of the Bixa 
orellana, a shrub indigenous to South America and the West Indies. 

A solution of the coloring matter in weak alkali is the form usually 
employed in milk. 

Nature of "Anilin Orange." — Of the coal-tar colors employed for 
coloring milk, the azo-dyes are best adapted for this purjDose and are 
most used. A few samples of these commercial "milk improvers" have 
fallen into the hands of the Department of Food and Drug Inspection 
of the Massachusetts Board of Health, and have proved, on examination, 
to be mixtures of two or more members of the diazo-compounds of anilin. 
A mixture of what is known to the trade as "Orange G" and "Fast Yel- 
low" gives a color which is practically identical with one of these prep- 
arations, secured from a milk-dealer and formerly used by him. 

For purposes of prosecution or otherwise, it is obviously best in our 
present knowledge of the subject to adopt a generic name such as "a 
coal-tar dye" or "anilin orange"* to designate this class of coloring 
matters in milk, rather than to particularize. 

Systematic Examination of Milk for Color. — The general scheme 
employed by the writer for the examination of milk samples suspected 
of being colored is as follows : j About 1 50 cc. of the milk are curdled by 
the aid of heat and acetic acid, preferably in a porcelain casserole over 
a Bunsen flame. By the aid of a stirring-rod, the curd can nearly always 
be gathered into one mass, which is much the easiest method of separa- 
tion, the whey being simply poured off. If, however, the curd is too 
finely divided in the whey, the separation is effected by straining through 
a sieve or colander. All of the annatto, or of the coal-tar dye present 
in the milk treated would be found in the curd, and part of the caramel. 
The curd, pressed free from adhering liquid, is picked apart, if necessary, 
and shaken with ether in a corked flask, in which it is allowed to soak 
for several hours, or until the fat has been extracted, and with it the 
annatto. If the milk is uncolored, or has been colored with annatto, 
on pouring off the ether the curd should be left perfectly white. If, on 

* The term "anilin orange" has been so commonly applied during the last eight years 
to any color or mixture of colors of this class in complaints in the Massachusetts courts, as 
to have acquired a special meaning perfectly well understood. 

t Jour. Am. Chem. Soc, 22, 1900, p. 207. 



136 FOOD INSPECTION AND ANALYSIS. 

the other hand, aniHn orange or caramel has been used, after pouring 
off the ether the curd will be colored more or less deeply, depending on 
the amount of color employed. In other words, of the three colors, 
annatto, caramel, and anilin orange, the annatto only is extracted by 
ether. If caramel has been used, the curd will have a brown color at 
this stage; if anilin orange, the color of the curd will be a more or less 
bright orange. 

Tests for Annatto. — ^The ether extract, containing the fat and the 
annatto, if present, is evaporated on the water-bath, the residue is made 
alkaline with sodium hydroxide, and poured upon a small, wet filter, 
which will hold back the fat, and, as the filtrate passes through, will allow 
the annatto, if present, to permeate the pores of the filter. On washing 
off the fat gently under the water-tap, all the annatto of the milk used 
for the test will be found to have been concentrated on the filter, giving 
it an orange color, tolerably permanent and varj'ing in depth with the 
amount of annatto present. As a confirmatory test for annatto, stan- 
nous chloride may afterward be applied to the colored filter, producing 
the characteristic pink color. 

Tests for Caramel. — The fat-freed curd, if colored after the ether 
has been poured off, is examined further for caramel or anihn orange, 
by placing a portion of the curd in a test-tube, and shaking vigorously 
with concentrated hydrochloric acid. If the color is caramel, the acid 
solution of the colored curd will gradually turn a deep blue on shaking, 
as would also the white fat-free curd of an uncolored milk, the blue colora- 
tion being formed in a very few minutes, if the fat has been thoroughly 
extracted from the curd; indeed, it seems to be absolutely essential for 
the prompt formation of the blue color in the acid solution that the curd 
be free from fat. Gentle heat will hasten the reaction. It should be noted 
that it is only when the blue coloration of the acid occurs in connection 
with a colored curd that caramel is to be suspected, and if much caramel 
be present, the coloration of the acid solution will be a brownish blue. If 
the abov'e treatment indicates caramel, it would be well to confirm its 
presence, by testing a separate portion of the milk in the following manner.* 

About a gill of the milk is curdled by adding to it as much strong 
alcohol. The whey is filtered off, and a small quantity of subacetate of 
lead is added to it. The precipitate thus produced is collected u;>on a 
small filter, which is then dried in a place free from hydrogen sulphide. 
A pure milk thus treated yields upon the filter-paper a residue which is 

* See Nineteenth Annual Report of the Mass. State Board of HeaUh (1887), p. 183- 



MILK. 



137 



either wholly white, or at most of a pale straw color, while in the presence 
of caramel, the residue is a more or less dark-brown color, according to the 
amount of caramel used. 

Tests for Coal-tar Dye. — If the milk has been colored with an azo-dye, 
the colored curd, on applying the strong hydrochloric acid in the test-tube, 
will immediately turn pink. If a large amount of the anilin dye has been 
used in the milk, the curd will sometimes show the pink coloration when 
hydrochloric acid is applied directly to it, before treatment with ether, 
but the color reaction with the fat-free curd is very delicate and unmistak- 
able.* 

Lylhgocf has shown that the amount of anilin orange ordinarily 
present in a milk for the purposes of coloring can be detected by adding 
directly to say 10 cc. of the sample an equal quantity of strong hydro- 
chloric acid and mixing, whereupon the pink coloration is produced, if 
the dye is present in more than minute traces. The test is more deli- 
cate if carried out in a white porcelain dish. It had best be used as a 
preliminary test only, and confirmed by a subsequent test on the fat-free 
curd as above. 

SUMMARY OF SCHEME FOR COLOR ANALYSIS. 

Curdle 150 cc. milk in casserole with heat and acetic acid. Gather curd in one mass. 
Pour off whey, or strain, if curd is finely divided. Macerate curd with ether in corked flask. 
Pour off ether. 



Ether Extract. 

Evaporate off ether, treat residue with 
NaOH and pour on wetted filter. After 
the solution has passed through, wash off 
fat and dry filter, which if colored orange, 
indicates presence of annatto. (Confirm 
By SnClj.) 



Extracted Curd. 

(i) // Colorless. — Indicates presence of 
no foreign color other than in ether extract. 

(2) // Orange or Brownish. — Indicates 
presence of anilin orange or caramel. 
Shake curd in test-tube with concentrated 
hvdrochloric acid. 



If solution gradu- 
ally turns blue, in- 
dicative of caramel. 
(Confirm by testing 
for caramel in whey 
of original milk.) 



If orange curd im- 
mediately turns pink, 
indicative of anilin 
orange. 



NATURE OF PRESERVATIVES USED IN MiLK.— In most localities 
having pure food laws preservatives in milk are regarded as adulterants. 

* Occasional samples of milk colored with a coal-tar dye of a different class from those 
already described have recently been found in Massachusetts. In these cases the color 
of the separated fat-free curd does not change when treated with hydrochloric acid. The 
color of the curd is, however, ven.' marked, being deep orange, bordering on the pink. 

t Jour. .\m. Chem. Soc, 22, 1900, p. 813. 



13S FOOD INSPECTION AND ANALYSIS. 

Their use, however, seems to be on the increase. Of 6,186 samples of milk 
examined by the Massachusetts State Board of Health during one year 
(1899) 71 samples, or 1.2%, were found to contain a preservative. Of 
these 55 were found with formaldehyde, 13 containing boric acid, borax, 
or a mixture of the two, and 3 contained carbonate of soda. 

Comparative tests have been made in the writer's laboratory of the 
keeping qualities of these commonly used milk preservatives, when present 
in varying strength, the milk being kept during the experiment at the tem- 
perature of the room, which at that season of the year (February) was about 
20° C* The preservatives were added about five hours after milking. 
The samples were titrated for acidity each morning, the acidity being 
expressed by the number of cubic centimeters of decinormal sodium 
hydroxide necessary to neutralize 5 cc. of the milk. 

The proportions of preservatives used in this experiment, as shown in 
the table on page 139, were intended to cover a wide range, from the 
weakest that could aid in preserving the milk up to a strength limited 
only by being perceptible to the taste. The table opposite shows the 
results. 

Formaldehyde, the most commonly used preservative for milk, is sold to 
the trade under various names, such as " Preservaline " "Freezine," "Ice- 
line," etc., all being dilute aqueous solutions of formaldehyde, containing 
from 2 to 6 per cent of the gas, being nearly always diluted from the 40% 
solution known as formalin. These preparations are usually accompanied 
by directions, which specify the amount to be used, varying from a table- 
spoonful of the solution in 5 to 10 gallons of the milk. It is commonly 
used in the strength of i part of the gas in 20,000, and rarely less than 
I part in 50,000. The antiseptic power of formaldehyde increases in a 
marked degree as the strength of the preservative is increased. Milk 
treated with i part in 10,000, for instance, according to the table was 
found to keep sweet 5 J days. In the strength of 1 part to 5000, the milk 
did not curdle for loj days, while i part of formaldehyde to 2500 parts of 
milk kept the rnilk from curdling for 55 days, the acidity up to that time 
being nearly normal. 

Formaldehyde is thus shown to be decidedly the most efficient of all 
milk preservatives, besides being inexpensive and convenient to use. 

Whether the grovrth of other bacteria than those that produce lactic 
fermentation is inhibited by formaldehyde in milk is not definitely settled. 
The claim has been made that pathogenic varieties are destroyed by its use. 

* Thirty-first Annual Report Mass. State Board of Health, 1S99, p. 611. 



MILK. 



139 



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140 FOOD INSPECTION AND ANALYSIS. 

Whether or not formaldehyde in milk is harmful to processes of diges- 
tion, when present in the amount commonly used, is still an open question.* 

Carbonate and Bicarbonate of Soda. — These substances are occasion- 
ally used in milk, though, as the above table shows, they possess little 
or no value as milk preservatives. They do, however, serve to neutralize 
the acidity of slightly soured milk and to postpone the time of actual 
curdling. 

Salicylic and Benzoic Acids, in view of the much more efficient anti- 
septics at hand, are now rarely used as milk preservatives, though the 
analyst should be on the outlook for them. Salicylic acid is a poor milk 
preservative, in view of the fact that it affects the taste of the milk, when 
present in sufficient quantity, to be of service. 

Detection of Formaldehyde. — Hydrochloric Acid Test.^ — Commercial 
hydrochloric acid (specific gravity 1.2) containing 2 cc. of 10% ferric 
chloride per liter is used as a reagent. Add 10 cc. of the acid reagent to an 
equal volume of milk in a porcelain casserole, and heat slowly over the 
free flame nearly to boiling, holding the casserole by the handle, and giving 
it a rotary motion wliile heating to break up the curd. The presence of 
formaldehyde is indicated by a violet coloration, varying in depth with 
the amount present. In the absence of formaldehyde, the solution slowly 
turns brown. By this test i part of formaldehyde in 250,000 parts of 
milk is readily detected before the milk sours. After souring, the limit 
of delicacy proves to be about i part in 50,000. 

Various aldehydes, when introduced into milk, give color reactions 
under the above treatment, but formaldehyde alone gives the violet colora- 
tion, which is perfectly distinguishable and unmistakable. 

Hehner's Sulphuric Acid Test. — To 5 to 10 cc. of milk in a wide test- 
tube add about half the volume of concentrated commercial sulphuric 
acid,J pouring the acid carefully down the side of the tube, so that it forms 
a layer at the bottom without mixing with the milk. A violet zone at 

* Milk-dealers are led to believe, by artful dealers in preservative preparations, that the 
chemist cannot detect them. The manufacturer of a widely used preservative, a weak solu- 
tion of formaldehyde, issues an attractive pamphlet in which he makes the following remark- 
able claims: 

"It is not an adulterant. It immediately evaporates, so that no trace of it can be found 
as soon as it has rendered all the bacteria inert. No chemical analysis can prove its pres- 
ence in milk, quantitatively or otherwise." 

t Annual Report Mass. State Board of Health, 1897, p. 55S; also 1899, p. 699. 

X The coloration produced seems to depend on the presence of iron salts in the acid, 
hence the use of commercial acid is recommended. If only pure acid is available, a little 
ferric chloride should be added 



MILK. 141 

the junction of the two liquids indicates formaldehyde. This test is 
not as delicate as the hydrochloric acid test, by reason of the charring 
action of the sulphuric acid. 

Confirmatory Tests with Distilled Milk. — If it is desired to confirm 
the above tests by further evidence, 100 to 200 cc. of the milk sample 
are subjected to distillation, and the first 20 cc. of the distillate are used 
for testing. 

(i) To a few drops of this distillate in a test-tube add a drop of Schiff's 
reagent.* In presence of any aldehyde, a pink coloration will soon be 
perceptible, deepening in intensity on standing. 

(2) Add to 5 cc. of the milk distillate a few drops of a 1% aqueous 
solution of resorcin or phenol, and proceed as directed on page 666 (pre- 
servatives). The crimson color indicates formaldehyde, and not other 
aldehydes. 

(3) Use I or 2 cc. of the milk distillate and apply the phenylhydrazine 
test, page 666. 

(4) A small amount of the distillate from milk (which prior to distilling 
is acidified slightly with sulphuric acid to fix any free ammonia) is treated 
with a few drops of Nessler's reagent. f Traces of formaldehyde produce 
a yellow coloration, while if considerable formaldehyde be present, the 
color darkens on standing and a grayish precipitate may be formed. 

Determination of Formaldehyde in Milk.| — To 100 cc. of milk add 
I cc. of 1 :3 sulphuric acid and subject to distillation in a 500-cc. Kjeldahl 
nitrogen-flask, using a low circular evaporating burner to avoid frothing. 
According to Smith, the first 20 cc. of the distillate, or one-fifth the 
original volume, contain very nearly one-third of the total formaldehyde. 
Collect 20 cc. of the distillate and determine the formaldehyde therein 
by the potassium cyanide method, as follows :§ 

Treat 10 cc. of tenth-normal silver nitrate with 6 drops of 50% nitric 
acid in a 50-cc. flask, add 10 cc. of a solution of potassium cyanide con- 
taining 3.1 grams of KCN in 500 cc. of water, and make up to the 50-cc. 
mark. Shake, filter, and titrate 25 cc. of the filtrate with tenth-normal 
ammonium sulphocyanate,|| using ferric chloride as an indicator. 

♦Table of reagents, No. 226. 

t Table of reagents, No. 187. 

X Smith, Jour. Am. Chem. Soc, 25, 1903, pp. 1032 and 1037. 

§ Zeits. anal. Chem., 36, pp. 18-24. 

II Theoretically 7.6 grams per liter On account of the deliquescent nature of the salt 
weigh out 8 grams, make up to a liter and titrate against tenth-normal silver nitrate for 
its exact value, using ferric chloride as an indicator. Sutton, Volumetric Analysis, 8th Ed, 
P- 155- 



142 FOOD INSPECTION AND ANALYSIS. 

Acidify another portion of lo cc. of tenth-normal silver nitrate with 
nitric acid, add lo cc. of the potassium cyanide solution to which the 
above 20 cc. of the formaldehyde distillate has been added. Make up 
the whole to 50 cc, filter and titrate as before 25 cc. of the filtrate with 
tenth-normal ammonium sulphocyanate for the excess of silver. 

The amount of potassium cyanide used up by the formaldehyde, in 
terms of tenth-normal ammonium sulphocyanate, is found by multiplying 
by two the diff^erence between the two results, and the total formal- 
dehyde is calculated by multiplying by 3 the amount found in the 20 cc. 
of distillate. 

The reaction that takes place between the formaldehyde and the 
potassium cyanide probably results in the formation of an addition 
product as follows: 

CH20-FKCN=KO.CH2CN. 

Detection of Boric Acid. — This is best accomplished by the turmeric- 
paper test in a solution of the ash of the milk, slightly acidified by hydro- 
chloric acid, in the manner described on page 66g. 

Determination of Boric Acid. — Use the method of Thompson.* Add 
10 cc. of a I : I solution of sodium hydroxide to 100 cc. of the milk, evaporate 
to dr}'ness in a platinum dish, and proceed as described on page 669. 

Detection of Carbonate and Bicarbonate of Soda. — The addition 
of carbonates is manifest by the effervescence caused by treating the 
milk-ash with acid. Effervescence in the milk-ash is quite perceptible, 
when as much as 0.05% of sodium carbonate is present. 

Schmidt's method of detecting sodium carbonate or bicarbonate, 
when present to the extent of 0.1% or more, is as follows: Ten cc. of 
milk are mixed with an equal volume of alcohol, and a few drops of a 
1% solution of rosohc acid are added. If carbonate is present, a rose- 
red color will be produced, while pure milk shows a brownish-yellow 
coloration. The suspected sample thus treated should be compared 
with a similarly treated sample of pure milk at the same time, to bring out 
the difference in color. 

Detection of Benzoic Acid. — Shake 5 cc. of hydrochloric acid with 
50 cc. of the milk in a flask. Then add 150 cc. of ether, cork the flask 
and shake well. Break up the emulsion which forms by the aid of a 
centrifuge, or, in the absence of a centrifuge, extract the curdled milk 
by gently shaking with successive portions of ether, avoiding the forma- 

* Jour. Soc. Chem. Ind., 12, p. 432. 



MILK. 



143 



tion of an emulsion. A volume of ether largely in excess over thai of 
the curdled milk has been found to be less apt to emulsionize.* Transfer 
the ether extract to a separatory funnel, and separate the benzoic acid 
from the fat by shaking out with dilute ammonia, which takes out the 
forme» as ammonium benzoate. Evaporate the ammonia solution in 
a dish over the water-bath till all free ammonia has disappeared, but 
before getting to dryness, add a few drops of ferric chloride reagent. 

The characteristic flesh-colored precipitate indicates benzoic acid. 
Care should be taken not to add the ferric chloride till all the ammonia 
has been driven off, otherwise a precipitate of ferric hydrate is formed. 

Detection of Salicylic Acid. — (i) To 50 cc. of the milk add i cc. of 
acid nitrate of mercury reagent (p. in), shake and filter. The filtrate, 
which should be perfectly clear, is then shaken with ether in a separatory 
funnel, the ether extract evaporated to dryness, and a drop of ferric chloride 
reagent applied. If salicylic acid be present, a violet color will be pro- 
duced. In carrying out the test it should be noted that a small portion 
only of the salicylic acid is in the filtered whey, the larger part being left 
in the curd. The color test is, however, so delicate as to show its presence, 
when an appreciable amount is used. 

(2) Proceed exactly as directed for benzoic acid (p. 142). On apply- 
ing the ferric chloride to the final solution, after evaporation of the 
ammonia, a violet color shows the presence of salicylic acid. 

Routine Inspection of Milk for Preservatives. — It is customary in the 
writer's laboratory to examine all the samples of milk collected during 
the months of June, July, August, and September for the commonly 
used preservatives, in addition to the regular analysis for total solids 
and fat. The number of samples thus examined amounts to upwards 
of 500 per month, varying from 10 to 60 per day. The results of such 
an examination during four years are thus shown : f 
PRESERVATIVES IN MILK. 



Year. 


Samples 
Examined. 


Number 
containing 

Form- 
aldehyde. 


Per Cent 
containing 

Form- 
aldehyde. 


Number 

containing 

Boric 

Acid. 


Per Cent 

containing 

Boric 

Acid. 


Number 
containing 
Carbonate. 


Total 
containing 
Preserva- 
tive. 


1808 


1046 
210:; 
201S 
2154 
1934 


26 

55 
6i 
42 
29 


2-S 
2.6 

1.9 
1-3 


II 

13 
6 

12 
14 


I.O 

0.6 
°'3 
°-5 
0.7 


4 
3 


41 
71 
67 
54 
43 


1800 


I goo 


igoi 


IQ02 




Totals. . . . 


9257 


213 


2-3 


56 0.5 


7 


376 



* When this process is used the ether may readily be recovered by distillation, 
t An. Rep. Mass. State Board of Health, 1902, p. 474; Analyst's Reprint, p. 22 



144 FOOD INSPECTION AND ANALYSIS. 

Such a system by no means involves a large amount of time or labor, 
and is really essential before passing judgment upon the purity of the 
milk, since, unlike added color, there is nothing in the physical appear- 
ance of the milk to suggest the presence of preservatives, nor are they 
rendered apparent by the taste, if skilfully used. « 

The methods employed are carried out as follows : * 

(i) Formaldehyde. — After having been examined for total sohds 
and fat, the milk samples are arranged in order in their original con- 
tainers, and about lo cc. of each sample are poured into a casserole and 
tested in succession by means of the hydrochloric acid and ferric chloride 
test (p. 140). A large stock bottle, which may be fitted with a siphon 
if desired, is kept on hand containing the hydrochloric acid reagent. 
Less than one minute is required in making the formaldehyde test for 
each sample. 

2. Carbonate and Boric Acid. — ^These tests have been so simphfied 
as to be, as it were, a side issue in the process of cleaning the platinum 
dishes used for the determination of total soUds. The various residues 
from the total sohds are burnt to an ash in the original numbered dishes 
in succession, these dishes, after incineration, being arranged side by side 
on a flat tray. By means of a pipette, one or two drops of dilute hydro- 
chloric acid are introduced into each dish in succession, noting at the 
time any effervescence that may ensue, which is in itself an indication 
of sodium carbonate. After every milk ash has been acidulated, a few 
cubic centimeters of water are added to each dish by means of a wash- 
bottle, the dissolving of the ash being hastened by giving a rotary motion 
to the tray containing the dishes. A strip of turmeric-paper is then allowed 
to soak for a minute or so in each dish, after which it is withdrawn from 
contact with the solution and allowed to adhere to the side of the dish 
above the liquid, where it remains until dry. If the paper when dry 
is of a deep cherry-red color, turning a dark olive when treated with 
dilute alkaH, the presence of boric acid is assured. These methods, 
are, of course, preliminary tests for quickly singling out the preserved 
samples. Such confirmatory tests as are desired may in all cases be 
employed. 

Another method of drying the strips outside the dishes is as follows: 

In a part of the laboratory free from dust, two long sections of glass 
rod or tubing are placed in parallel lines over filter-paper, as in Fig. 48, 

* Leach, Analyst, XXVI, p. 289. An. Rep. Mass. State Board of Health, 1901, p. 447 
Food and Drug Reprint, p. 27. 



MILK. 145 

with numbers marked on ihe paper at close intervals corresponding to 
the numbers of the platinum dishes. The strips of turmeric-paper, after 
soaking, are removed from the dishes and placed across the glass tubes, 
over the numbers corresponding to those of the dishes from which they 
were taken. Here they are allowed to stand till dry, being kept in posi- 
tion by a third section of tube or rod placed over them. When dry, the 




Fig. 48. — Arrangement of Glass Rods and Turmeric Test-papers in Detection of Boric 

Acid in Milk. 

color of the turmeric strips will indicate whether or not boric acid is present, 
and also the position will show in what sample to look for it. 

Cane Sugar. — This is alleged to be added for the purpose of increasing 
the total solids of milk, but if present to any marked degree, it could 
hardly fail of detection by reason of the sweet taste imparted to the milk. 
Cane sugar in milk may be detected * by boiling 5 to 10 cc. of the sample 
with about o.i gram of rcsorcin and a few drops of hydrochloric acid for 
a few minutes. In the presence of cane sugar, a rose-red color is produced. 

According to Richmond, cane sugar may be estimated by first ascer- 
taining the total polarization of the sample as in the estimation of milk 
sugar (p. 112). The milk sugar is then determined by Fehling's solution 
(pp. 113 to 115) either volumetrically or gravimetrically. The difference 
between the anhydrous milk sugar found by the latter, or Fehling method, 
and that calculated by dividing the polarization by 1.2 17 will give the 
percentage of cane sugar present. 

Cotton's t method of detecting cane sugar, when present to the extent 
of 0.1%, consists in mixing in a test-tube 10 cc. of the suspected "milk 
with 0.5 gram of powdered ammonium molybdate. Ten cc. of milk of 
known purity, or 10 cc. of a 6% solution of milk sugar are similarly treated 
by way of comparison. Both tubes are placed in a water-bath and 
the temperature gradually raised to 80° C. If cane sugar is present, an 
intense blue coloration is produced, while the genuine milk or the solution 
of milk sugar remains unchanged at the temperature of 80°. If the tem- 
perature is raised to the boihng-point, however, the pure milk or milk 
sugar solution may also turn blue. 

* Richards and Woodman, Air, Water, and Food, p. i66 
t Abs. Analyst, 1898, p. 37. 



146 FOOD INSPECTION AND ANALYSIS. 

Detection of Starch in Milk. — A small quantity of milk is heated in 
a test-tube to boiling, cooled, and a drop of iodine in potassium iodide 
added. A blue coloration indicates starch. 

Condensed Skimmed Milk as an Adulterant. — The use of condensed 
unsweetened skimmed milk to raise the solids of a skimmed or watered 
milk above the standard has been noted in Massachusetts. This sophis- 
tication is rendered apparent by the abnormally high solids not fat of 
the sample, which in some instances have exceeded 11%. A solid not fat 
in excess of 10% is suspicious of this form of adulteration. By fixing a 
legal standard for both fat and solids not fat, such tampering with milk 
may readily be checked. 

Analysis of Sour Milk. — It occasionally becomes necessary for the 
analyst to deal with samples of sour milk, especially in the summer-time, 
when the milk has been brought from a long distance. While the process 
of lactic fermentation results in the formation of traces of volatile acids, 
unless the sample has become so badly curdled as to render an even homo- 
geneous mixture of the various parts impossible, a fair determination of 
the solids and fat can readily be made. Experience has proved that, 
excepting in instances of milk so badly soured as to have become actually 
putrid, the analysis of sour milk, if carefully made, should not differ 
materially from that of the same milk before souring. 

Care must be taken to secure an even emulsion of the curd and whey. 
This may sometimes be accompUshed by repeatedly pouring the sample 
back and forth from one container to another. Again, it is sometimes 
necessary to use an egg-beater of the spiral wire pattern, which preferably 
should easily fit the can or milk-container. Unless a fine, even emulsion 
can be secured, it is impossible to make a satisfactory analysis of sour 
milk. With sucli an emulsion results can be relied on. 

In measuring portions of the thoroughly mixed sample of sour milk 
for analysis, a pipette should be used having a large opening.* 

CONDENSED MILK. 

Canned condensed milk has become a very important article of food, 
its use having increased considerably during the last few years. The 
universally accepted meaning of the term ' ' condensed milk" in this country 
is milk both condensed and preserved with cane sugar, being what is com- 
monly known in England as "preserved milk." The unsweetened variety 
is more often termed ' ' evaporated cream " and sold as such. It is, however, 

* A pipette open to the full size of the tube is convenient for this work. 



MILK. 



147 



as found on the market usually nothing better than condensed ordinary 
milk, having no added sugar, and has generally no resemblance in com- 
position to cream other than in consistency. 

Condensed milk is usually prepared by boiling milk in vacuum-pans 
under diminished pressure to the proper degree of concentration. Up- 
wards of 350 samples of sweetened condensed milk have been analyzed 
in full in the laboratory of the Massachusetts State Board of Health during 
the last eight years, representing no less than no brands, together with 
about 30 samples (representing 8 brands) of the unsweetened variety. 

In view of the fact that a considerable number of the condensed-milk 
samples are shown by their analysis to have been produced from skimmed 
milk, the fat content in the samples analyzed varying from a mere trace 
to 12%, it is obvious that the typical composition of condensed milk could 
not fairly be shown by giving maximum, minimum, and mean results 
from the entire tabulated series, nor would it be possible to draw a hard- 
and-fast line excluding certain samples known to be adulterated in making 
up the averages. It has therefore been thought best to select a few typical 
brands and give their analyses in full. 

COMPOSITION OF SW^EETENED CONDENSED MILK. 



Points to be Noted. 



Total 

Solids, 

Per 

Cent. 



Water 
Per 
Cent. 



Milk 
Solids, 

Per 
Cent. 



Cane 
Sugar, 

Per 
Cent. 



Milk 
Sugar, 

Per 
Cent. 



Pro- 
teids, 

Per 
Cent. 



Fat, 

Per 

Cent. 



Ash, 

Per 

Cent. 



Fat in 

Origi- 
nal 

Milk, 
Per 

Cent. 



No. of 
Times 
Con- 
densed 



High in fat, much added 

sugar 

High fat, low milk sugar. . . 
lx)w fat, high milk sugar; 

low proteids 

Normal constituents 

throughout* 

Condensed from skimmed 

milk 

Condensed from centrifu- 

gally skimmed milk 



7Q.I7 
68.70 

69.30 

74.29 

69.30 

69.06 



20.83 
32.30 

30.70 

25.71 

30.70 

30.94 



31.32 
30.27 

31.83 

32-37 

29.15 

25.88 



47.85 
38.43 

37-47 

41.92 

40. IS 

43-i8 



9-57 
6.38 

16.75 

11.97 

11.89 

II. SS 



7. 05 

10.70 

6-34 

8. 46 

12.15 

n.78 



12.00 
II .46 



1.80 
1-73 



7.20 I. 54 

10.65 I .29 

3.06' 2.05 

o . 09 2 . 46 



5.71 
5-78 

2-74 

4.67 

I .09 

Trace 



COMPOSITION OF UNSWEETENED CONDENSED MILK. 



Points to be Noted. 



High in fat 

Low in proteids 

Normal constituents throughout* 
Condensed from skimmed milk . . 



Total 

Solids. 

Per 

Cent. 



36.00 
31.25 
28.16 
35.17 



Water, 

Per 

Cent. 



64. CO 

86.75 

69-24 

64. S3 



Milk 
Sugar, 

Per 
Cent. 



10.65 

13-40 

9-85 

13.90 



Pro- 
teids, 

Per 
Cent. 



11.63 
7.02 
8.66 

15-37 



Fat, 

Per 

Cent. 



12.00 
9 .60 



Ash, 
Per 
Cent. 



1-23 
I-5S 
1.70 



Fat in 

Original 

Milk, 

Per 

Cent, 



4.61 
4.18 
3-68 
1.28 



No. of 
Times 
Con- 
densed. 



2.6 
2-3 
2 . 3 
ii 



* Can be taken as being very near the average for all constituents in honest condensed milk of 
fair quality. 



1 48 FOOD INSPECTION AND ANALYSIS. 

In the case of sweetened condensed milk it will be observed that 
the proteids as a rule run considerably lower than the sugar, whereas 
in ordinar}' cow's milk the percentage of proteids and milk sugar are 
more nearly alike. In making the above analyses all the reducing sugar 
was reckoned as milk sugar, whereas it is possible that a small amount 
of the cane sugar is inverted in the process of manufacture, and thus 
increases the amount of reducing sugar. 

U. S. Standards.* — Standard condensed milk and standard sweetened 
condensed milk are condensed milk and sweetened condensed milk re- 
spectively, containing not less than 28% of milk solids, of which not less 
than one-fourth is milk fat. Standard condensed skim-milk, is skim- 
milk from which a considerable portion of water has been evapo- 
rated. 

Methods of Analysis. — Preparation 0} the Sample. — For the analysis 
of condensed milk the following system of procedure has been adopted 
in the laboratory of the Massachusetts State Board of Health. The 
sample is first thoroughly mixed, best by transferring the entire contents 
of the can to a large cvaporating-dish, and working it thoroughly with 
a pestle till homogeneous throughout. Forty grams of the mixed 
sample are weighed out, preferably in a tared weighing-tray for sugar 
analysis, transferred by washing to a graduated loo-cc. sugar-flask (or 
if desired it is weighed directly into the flask) and made up to the mark 
with water. 

Total Solids. — An aliquot part of this mixed solution is further diluted 
with an equal amount of water, and 5 cc. of the diluted mixture, corre- 
sponding to I gram of the condensed milk, is pipetted into a tared platinum 
dish, such as is used for ordinary milk, the pipette being rinsed into the 
dish by means of a wash-bottle. The dish with its contents is then placed 
on the water-bath, and distilled water added by the wash-bottle till the 
dish is nearly full. It is allowed to remain in contact with the live steam 
of the water-bath for at least two hours after the last traces of water have 
been evaporated off to leave an apparently dry residue. It is then trans- 
ferred to a desiccator, cooled, and weighed. 

It is of great importance to have the sample very dilute to properly 
determine the total solids in this manner. Formerly the sample was 
evenly distributed over asbestos fiber in the dish, but more accurate 
results were found possible by the above method. The character of 
the residue should be noted. It should not, excepting in the case of a 

* U. S. Dept. of Agric, Off. of Sec, Circ. lo. 



MILK. 149 

skimmed milk, be caked down hard and glossy on the bottom of the 
dish, but, if the operation is properly carried out, should have a well-sepa- 
rated fat layer at the top, and the residue should resemble in appearance 
that from ordinary' milk. This result is accomjilishcd by the extreme 
dilution of the sample. 

Ash. — The residue from the total solids as above obtained is care- 
fully burnt, cooled, and weighed as in the case of ordinary milk (p. 98). 

When the total solids are not to be determined, as in cases where 
the cjuality of the milk used in preparation of the sample is decided by 
the fat and ash alone (see p. 152), 12.5 cc. of the above 40% solution, 
corresponding to 5 grams of the sample, are evaporated to dryness on 
the water-bath, and the residue burnt to an ash in the muffle or over a 
low flame. 

Fat. — The Aulhor^s Method.* — Fifteen cc. of the 40% solution pre- 
pared as above described, corresponding to 6 grams of the original con- 
densed milk, are measured into an ordinary test-bottle of the Babcock 
centrifuge. This is filled nearly to the neck with water, and 4 cc. of a 
solution of copper sulphate of the strength of Fehling's copper solution 
are added. The contents are thoroughly shaken, and the precipitated 
proteids, carrying with them the fat are rapidly separated out by whirl- 
ing the fat bottle in the centrifuge, preferably without heating. The 
writer prefers an electric centrifuge of the Robinson type (p. loi) for 
this purpose, as the heat of the steam-driven machine cakes the precipitate 
down, so that it is harder to wash. If desired, the precipitate may be 
allowed to settle out of itself, which it does more cjuickly in the cold. 

The supernatant liquid containing the sugar is drawn off by means of 
a pipette of large capacity, having a stem sufficiently small to pass easily 
into the neck of the milk-bottle, a small wisp of absorbent cotton being 
first twisted over the bottom of the pipette to serve as a filter. On with- 
drawing the pipette with the sugar solution, the cotton is wiped off into 
the bottle by rubbing against the inner side. 

The precipitated proteids and fat are given two additional washings, 
as above, by shaking thoroughly with water introduced nearly to the 
neck of the bottle, separating out in each case by centrifuge or by settling, 
and finally removing the washings with the pipette, two of such extra 
washings being found nearly always sufficient to remove all the sugar. 
If the precipitate is caked down hard after treatment with the centrifuge, 

* 28th An. Rep. Mass. State Board of Health, 1896, p 630, and Jour. Am. Chem. Soc., 

22, igoo, p. 589. 



15° FOOD INSPECTION AND ANALYSIS. 

it may be necessary to employ a stiff platinum wire as a stirrer to aid in 
mixing with the wash-water. 

Finally, enough water is added to amount approximately to the nor- 
mal volume of 17.6 cc. usually employed for the Babcock test, 17.5 cc. 
of sulphuric acid are added, and the test continued from this point on 
as in the ordinary Babcock process of milk-testing, multiplying the read- 
ing obtained by three to give the correct percentage of fat in the 
sample. 

For condensed milk containing no added cane sugar, these precau- 
tions are, of course, unnecessary, the ordinar)- Babcock method being 
directly employed with a weighed portion of the milk. 

Proteids. — Five cc. of the 40% solution originally prepared, corre- 
sponding to 2 grams of the condensed milk, are diluted further to about 
40 cc, and just enough of the Fehling copper solution is added, drop 
by drop, to precipitate the albuminoids, taking care to avoid a large 
excess. As a rule, 0.6 cc. of copper solution is ample for this. Nearly 
neutralize with sodium hydroxide, stopping just short of alkalinity, i.e., 
leaving the solution still slightly acid. An excess of alkali tends to dis- 
solve the casein and cause turbidity in the filtrate. Pass through a 
weighed filter-paper, wash, dry in an air-oven at 100° C, and weigh. The 
filter with the dry precipitate is then carefully burnt in a porcelain cru- 
cible,, and the difference between the weight of the dry precipitate and 
the weight of the ash is the weight of the proteids and fat. Expressing 
this in percentage, and deducting from it the per cent of fat previously 
obtained, the result is the per cent of proteids. 

Milk Sugar. — The filtrate and the washings from the preceding oper- 
ation are made up to 100 cc. with water, and the amount of reducing 
sugar, obtained volumetrically by Fehling's solution, is reckoned as 
milk sugar. The titration is conducted in the manner described on 
p. 486. 

Assuming the solution to be exactly of the strength above described, 

100-I-.067 
the milk sugar is calculated as follows: —^ =L, where L is the 

5-f.02 

per cent of lactose or milk sugar, and 5 the number of cc. of milk 
solution, prepared as above required to reduce 10 cc. of Fehling's 
solution. Calculation may be avoided by the use of the following 
table, which may be employed when the above details are minutely 
carried out: 



MILK. 



151 



PER CENT MILK SUGAR CORRESPONDING TO NUMBER OF CUBIC 
CENTIMETERS USED. 

Strength of solution 2 grams in 100 cc. 



Cu. Cm. 


Per Cent. 


Cu. Cm. 


Per Cent. 


Cu.Cm. 


Per Cent. 


Cu. Cm. 


Per Cent. 


18.0 


18.61 


25-0 


13-40 


32.0 


10.47 


39-0 


8-59 


18.S 


18.10 


25-5 


13-14 


32-5 


10.31 


39-5 


8-49 


ig.o 


17-63 


26.0 


12.89 


33-0 


10. 15 


40.0 


8-37 


19-5 


17.18 


26.5 


12.64 


33-5 


10.00 


40-5 


8-27 


ro.o 


•6-75 


27.0 


12.41 


34-0 


9-85 


41.0 


8.17 


20.5 


16.34 


27.5 


12.18 


34-5 


9-71 


41-5 


8.07 


21.0 


15-95 


28.0 


11.97 


35 -0 


9-57 


42.0 


7-98 


21-5 


15-58 


28.5 


11-75 


35-5 


9-43 


42.5 


7.88 


22.0 


15.22 


29.0 


"-55 


36.0 


9-3° 


43-° 


7.78 


22-5 


14.89 


29-5 


11-35 


36-5 


9.17 


43-5 


7.70 


23.0 


14-56 


30.0 


1 1 . 16 


37-° 


9-05 


44.0 


7.61 


23-S 


14-25 


3° -5 


10.89 


37-5 


8-93 


44-5 


7-53 


24.0 


13-95 


31-° 


10.80 


38.0 


8.81 






24-S 


13-67 


31-5 


10.63 


38-5 


8.70 







Cane Sugar. — This is obtained by difference, deducting the milk 
solids (the sum of the milk sugar, proteids, fat, and ash) from the total 
solids first obtained. 

Fat in Sweetened Condensed Milk. — Judgment as to the quality of 
a given brand of condensed milk is naturally based more on its fat content 
than on any other one factor, in that, of all its constituents, the fat is the 
only one that can conveniently be tampered with to the detriment of its 
value as a food. Hence, an accurate method for the determination of 
the most important ingredient, the fat, is of great importance. 

The Babcock process without modification cannot be used, on account 
of the charring by the sulphuric acid acting on the cane sugar. 

The Adams-Soxhlet method is unreliable, because the large amount of 
cane sugar is again a disturbing factor, enclosing the fat particles so firmly, 
when dried on the extraction coil, as to render its complete removal by 
the extracting ether difficult if not impossible.* In 1895 the writer's 
method described on page 149 was devised, and with certain minor modifi- 
cations has been used ever since with highly satisfactory' results, proving 
itself to be not only much quicker than the Adams-Soxhlet extraction 
method and easier of manipulation, but, indeed, more accurate, by reason 



* When ordinan' ether is used for the So.xhlet extraction, the resuhs may not appear too 
low because the alcohol and water present in the ether dissolve not only fat but also sugar, 
which goes in with and is weighed as fat. With ether carefully dehydrated and freed from 
alcohol or with benzine or petroleum ether, the fat results will always be found far too low 
when the extraction is conducted under ordinary conditions. 



152 FOOD INSPECTION AND /IN /I LYSIS. 

of the fact that the cane sugar with all its attendant troubles is first ehmi- 
nated.* 

Calculation of Fat in Original Milk. — The "fat in the original milk," 
as expressed in the tables on page 147, was calculated by assuming a 
percentage of solids not fat of 9.3 in the original milk, this being the standard 
fixed by the Massachusetts law. The per cent of milk solids not fat in 
the condensed milk (i.e., proteids + milk sugar + ash) divided by 9.3 gives 
the " number of times condensed." The per cent of fat in the condensed 
sample, divided by the latter factor, or number of times condensed, gives 
as a result the "fat in the original milk." 

Another method has recently been adopted by the writer for calculation 
of fat in the original milk, based on the ash rather than the solids not fat. 
By this method the calculation may be made without a complete analysis 
of the sample, but by simply determining the fat and ash. 

Assuming .70% as the ash of pure milk, the factor representing the 
" number of times condensed " is found by dividing the ash of the con- 
densed milk by .70. The fat in the original milk is then computed by 
dividing the per cent of fat in the sample by the "number of times con- 
densed." t 

If the fat in the original milk is found to be well below 3%, there is 
reason to suspect that skimmed milk was used in its preparation. 

Other Methods for Proteids and Cane Sugar. — If desired, the proteids 
of condensed milk can be calculated from the total nitrogen obtained by 
the Gunning method as in ordinary milk (p. 109). 

Bigelow and McElroy's Polar imetric Method jor Cane Sugar. t — 26.048 

* Parallel determinations of fat in sugar-preserved milk by the Adams-So.xhlet process, 
using ether carefully dehydrated and freed from alcohol, and by the writer's method involv- 
ing the use of the Babcock machine, show in all cases a larger fat content by the latter or 
modified Babcock process. Indeed, in one instance an e.xtraction of sixty hours was retjuired 
in the case of the Soxhlet process to equal the percentage of fat found by the modified Bab- 
cock process, so firmly were the fat particles inclosed by the cane sugar on the extraction 
coil, thus resisting the action of the ether. It is obvious that, in the case of the modified 
Babcock process, no more fat can be shown by the final result than actually exists in the 
milk; indeed, if anything, one would expect a slight loss, so that, when compared with the 
Soxhlet method, if the latter shows lower figures, it can safely be presumed that the process 
is unreliable. 

t The "fat in the original milk" as thus calculated is, of course, an arbitrary factor and 
is useful only in deciding whether or not skimmed milk has been used in preparing the 
sample. By assuming the above very reasonable figures for the solids not fat, or for the 
ash of natural milk (according to which method is used for calculation), it is readily seen 
that the highest result is obtained for the "fat in the original milk" and hence the benefit 
of the doubt as to the use of skimmed milk is given to the manufacturer. 

J Jour, .^m. Chem. Soc, 15, p. 668. 



MILK. 153 

grams of the mixed sample of condensed milk are transferred to a loo-cc. 
graduated sugar-flask and dissolved in water, which is boiled to make 
sure of normal rotation. The solution is then clarified by the addition 
of an acetic acid solution of mercuric iodide * and, if necessary, alumina 
cream, the volume is made up to 100 cc, shaken, and filtered through 
a dry fihcr. Rejecting the first part of the filtrate, a further portion is 
polarized. For inversion, another sample of 26.048 grams is weighed 
out as before and dissolved, but before clarifying, is heated to 55° C. 
and treated with half a cake of compressed yeast, the heating with the 
yeast being continued at 55° for five hours. The clarifying solution 
is added before coohng, and, after cooling, making up to 100 cc, and 
fihering as before, the invert reading is obtained with the polariscope. 
By this process of yeast inversion the cane sugar only is inverted, the 
lactose remaining unchanged. It is best to work with several samples 
and use the mean of the readings both for direct and invert figures. It is 
also best to use the double dilution method (p. 113) to compensate for 
the volume of the precipitated fat and proteids. 

The per cent of cane sugar is calculated by the formula of Clerget, 

-^ t' 

144 -- 

5 being the per cent of cane sugar, 
A the direct reading, 

B the invert reading and t the temperature at which the observation is 
made. 
The above process presupposes the absence of invert sugar in the 
sample, a supposition which Wiley claims it is fair as a rule to assume. 

CREAM. 

Composition. — Cream varies in composition according to the method by 
which it is obtained, i.e., whether (i) by allowing it to separate from the 
milk set in shallow pans, whence it is removed by hand-skimming, (2) by 
setting in deep vessels surrounded by cold water (as for example in the 
"Coolcy" creamer) the skimmed milk being commonly drawn off from 
below, or (3) by the centrifugal separator. Most of the heavy cream 
found in the market at the present time is the product of the third or sepa- 
rator process. 

* Prepared by dissolving 53 grams of potassium iodide, 22 grams mercuric chloride, and 
32 cc. of strong acetic acid in water and making up to i liter. 



IS4 



FOOD INSPECTION ^ND ANALYSIS. 



COMPOSITION OF CREAM. 



Character of Cream. 


2 


•c 



1 




u 

Si 


•a 
'B 

& 


1 




4 
< 






c 

r 


By natural separation 

By centrifugal separator, 


46 

18 

18 


Konig 
Leach 

Leach 


Mean 

Maximum 

Minimum 

Mean 

Maximum 

Minimum 

Mean 


68.82 

54.80 
46.76 

51. 68 
83.29 

70-5° 
77.89 


3-76 


22.66'4.23 


°-53 


31.18 

53-24 
45-20 

48.32 
29.50 
16.71 

22.11 


8.42 

8.50 
4.20 
6.30 

9-30 
7.22 
8.2s 




38.10 

42.02 
21.60 

8.60 
13.86 








Methods of Analysis. — The total solids, asli, sugar, and proteids are 
determined by similar processes to those used in milk analysis. 

Fat. — The most convenient method of estimating fat is slightly modi- 
fied from the regular Babcock process. The specific gravity of cream 



n 




varies between such wide limits that it is 
best to weigh rather than measure the 
sample. Two varieties of cream bottle 
are in common use (Fig. 49) for the 
Babcock process, with a capacity for 
measuring 25 to 30 per cent of fat. 

Approximately 10 grams of the well- 
mixed cream sample are transferred to 
one of these cream bottles, previously 
tared, and the weight of the cream ac- 
curately obtained. A convenient pipette 
to use for the purpose is one the end of 
which has been broken off to the full size 
of the tube. 

Fig. 50 shows a cream-test scale spe- 
cially designed for weighing the sample, 
provided with a sliding poise for counter- 
balancing the bottle, and a second weight 
for weighing the cream. The scale is 
delicate to o.oi gram when loaded. 
Five to 6 cc. of water are added to the 
cream in the bottle, after which the regular amount of sulphuric acid 
used in the Babcock milk test (17.5 cc.) are measured in, and the test 
continued in the regular manner employed for milk. The reading of 




Fig. 49. — Varieties of Babcock Test 
Bottle for Cream. 



MILK. 



155 



the fat is mullipliwl by 18 and the product, divided by the weight of 
cream taken, gives the per cent of fat. 

U. S. Standards.* — Standard Cream is cream containing not less than 
18% of milk fat. 

Standard Evaporated Cream is cream from which a considerable portion 
of water has been evaporated. 

Adulteration of Cream. — In some localities fat standards are fixed 
for cream both "heavy" and "light," those falling below such standards 
being deemed adulterated. 

The same preservatives are employed in cream as in milk, and are 




Fig. 50. — K Babcock Cream-test Scale. 



detected in the same way'. The color reaction for formaldehyde, by heat- 
ing with hydrochloric acid and ferric chloride, is not as delicate in the case 
of cream as of milk, by reason of the large amount of fat. Before making 
the test the sample is preferably diluted with an equal volume of water, the 
heating is done in a casserole as with milk, but finally pour into a test- 
tube, and observe the color of the aqueous layer. 

Gelatin in Cream. — Gelatin has been found by the writer in a number 
of samples of Massachusetts cream, its use being to increase the consistency. 
It was possible in one instance to obtain a sample of the adulterant used 
in the form of a powder, which proved on analysis to be chiefly gelatin 

* U. S. Dept. of Agric, Off. of Sec, Circ. 10. 



156 FOOD INSPECTION AND /ANALYSIS. 

with a small mixture of boric acid, these ingredients serving the two-fold 
purpose of thickening and preserving the cream. 

Gelatin is best detected in cream or milk by the method of Stokes.* 
He uses for reagents (i) acid nitrate of mercur)', prepared by dissolving 
metallic mercury in twice its weight of concentrated nitric acid (sp. gr. 
1.42) and diluting with twenty-five times its bulk of water, and (2) a 
saturated aqueous solution of picric acid. 

To about 10 cc. of the cream add the same amount of the acid nitrate 
of mercury solution and 20 cc. of cold water. The mixture is shaken vigor- 
ously and allowed to rest for five minutes, after which it is filtered. If 
much gelatin is present, the filtrate will not be clear, but opalescent. To 
the whole or a part of the filtrate a few drops of the picric acid solution 
are added, and if gelatin be present in any considerable amount, a yellow 
precipitate is formed. Avoid an excess of acid nitrate of mercury, as this 
would cause a precipitate with picric acid. 

If gelatin is present in small amount only, a cloudiness is produced, 
best seen against a dark background. In the absence of gelatin, the 
solution will remain perfectly clear after adding the picric acid. The 
reaction is dehcate to i part of gelatin in 10,000 parts of milk or cream. 

Sucrate of Lime in Cream. — In the ordinary process of pasteurizing 
thick cream, a process which is becoming more and more prevalent, the 
consistency becomes reduced, so that while the value of the cream is actu- 
ally enhanced on account of its freedom from bacteria and its increased 
capacity for keeping, its apparent richness is impaired when compared 
with untreated cream of the same composition. To restore this reduced 
consistency, Babcock and Russell f have shown that sucrate of lime may 
be used to advantage. They have applied the term "viscogen" to this 
compound, and have suggested that cream so treated, in order to be sold 
legally, should be knovm by some distinctive trade name as "visco- 
cream" or "pasteurized visco-cream. " 

' ' Viscogen " is prepared by dissolving 3^ parts by weight of cane sugar 
in 5 parts water, and adding thereto, after straining, i part of quicklime 
slaked in 3 parts water. After shaking and settling, the supernatant 
liquid is syphoned off and bottled for use. It will thicken cream, milk, 
or condensed milk. The amount recommended to be added to cream 
should be two-thirds of the amount found by experiment necessary to 
neutralize its acidity. 

A cream sample treated by the writer with 5 cc. of viscogen per quart 
* Analyst, 22, p. 320. f Wisconsin Exp. Station Bulletin 54. 



MILK. IS7 

was found to yield an ash of 0.38 per cent, a solution of which required 
to neutralize it 0.31 cc. of tenth-normal sulphuric acid. The same cream 
untreated had an ash amounting to 0.34% and required 0.08 cc. tenth- 
normal sulphuric acid to neutralize. 

BUTTER. 

The value of butter as a food depends almost entirely on its fat con- 
tent, although minute quantities of protein and milk sugar are also in- 
cluded in its composition. 

Hence butter is more logically treated in detail under the heading of 
fats (page 430). 

CHEESE. 

Nature and Composition. — Cheese consists principally of the curd 
and fat removed in a mass from milk, which has been curdled by the 
natural souring of the milk, or by the action of rennet. The separated 
mass of curd and fat, after being compressed, is allowed to undergo certain 
changes, which constitute the ripening or curing, due to the action of 
micro-organisms and enzymes. Sometimes cream is used as the source 
of cheese and sometimes skimmed milk. During the ripening process, 
which requires from a few weeks to several months, the characteristic 
flavor is developed by the changes which the proteids undergo, and the 
digestibihty of the cheese is improved. The nature of the proteolytic 
changes that take place during ripening are very httle understood, but a 
variety of complex nitrogenous products are formed, which Van Slyke 
divides as follows: paracasein, unsaturated paracasein lactate, para- 
nuclein, caseoses (albumoses), peptones, amides, and ammonia. Besides 
nitrogenous bodies and fat, which are its chief constituents, cheese con- 
tains notable quantities of water, milk sugar, lactic acid, and mineral 
matter. 

In some kinds of cheese salt and coloring matter are added. 

Varieties. — Well-known cheeses of commerce are often named from 
districts, towns, or localities where they originated or are still made. 
They may be classified as cream, whole-milk, or skimmed-milk cheese, 
according to the quality of the product from which they are made, or 
again as hard, medium, or soft, according to whether (i) they are pressed, 
or (2) allowed to drain for days and sometimes weeks without pressure 
to a firm consistency, or (3) are made in the space of a few hours, being 
quickly drained on a sieve by hand pressure. 



158 



FOOD INSPECT/ON AND AN /I LYSIS. 



Cheddar Cheese, which is the common cheese of the United States 
(though originally made some 250 years ago in England and still made 
there), is a type of the hard cheese. Stilton, an English, and Gruyhre, a 
Swiss cheese, belong to the medium class, and soft cheeses are represented 
by Brie and Neujchatel, both French cream cheeses. Other well-known 
varieties are Edam, a round, mild, long-keeping Dutch cheese, Cammembert, 
a rich cream cheese, and Roquefort, made originally from ewe's milk in 
the French town of that name, and ripened in caves in the mountains. 
It is flavored by a pecuHar mold. 

The following table, compiled by Woll,* shows the average composition 
of various cheeses of commerce, both foreign and domestic: 



Cheddar 

Cheshire 

Stilton 

Brie 

Neufchatel 

Roquefort 

Edam 

Swiss 

Full cream, mean of 143 analyses 



Water. 


Casein. 


Fat. 


Sugar. 


Per cent. 


Per cent. 


Per cent. 


Per cent. 


34.38 


26.38 


32-71 


2-95 


32-59 


32-51 


26.06 


4-53 


3°-35 


28.85 


35-39 


1-59 


5°-35 


17.18 


25-12 


1.94 


44-47 


14.60 


33-7° 


4-24 


31.20 


27.63 


33-^^ 


2.00 


36.28 


24.06 


30.26 


4.60 


35-80 


24.44 


37-40 




38.60 


25-35 


30-25 


2.03 



Ash. 
Per cent. 

3-58 
4-31 
3-83 
5-41 

2-99 
6.01 
4. go 
2.36 
4-07 



Van Slyke has furnished the following analysis of the nitrogen com- 
pounds in a sample of normal American Cheddar cheese six months 
old and cured at 60° F. : 



Per Cent 

Nin 
Cheese. 


Per Cent 
Water- 
soluble N. 


Per Cent 

Nas 

Paracasein 

Mono- 

lactate. 


Per Cent 

N as Para- 

nuclein. 


Per Cent 

Nas 
Caseoses. 


Per Cent 

Nas 
Peptones. 


Per Cent 

Nas 
Amides. 


Per Cent 

N as 
Ammonia. 


3.80 


1.46 


0.94 


0.14 


0.22 


0.18 


0.79 


0.13 



U. S. standards. I — Standard Whole-milk Cheese or Full-cream Cheese 
is whole-milk or full-cream cheese containing in the water-free substance 
not less than 50% of butter fat. 

Cream Cheese is cheese made from milk or cream, or milk containing 
not less than 6% of fat. 

Adulteration. — Cheese is commonly adulterated in two ways: first, 
by the partial or total substitution for the milk fat of a foreign fat, as oleo- 
margarine or lard, and, second, by using skimmed milk as a material 
for its manufacture. 



• Dairy Calendar, p. 223. 



t U. S. Dept. of Agric, Off. of Sec, Circ. 10. 



MILK. 159 

In many localities a standard percentage for fat in cheese is fixed by 
law, as in the case of the U. S. standard noted above, all samples falling 
below that standard, unless sold as skim-milk cheese, being deemed adul- 
terated. 

Some states have specific standards for varying grades of cheese, 
classified as to their fat content. Thus under the Pennsylvania law * 
cheese is divided into five grades, as follows: 

Full-cream cheese must contain not less than 32% butter fat. 

Three-fourths cream cheese must contain not less than 24% butter 
fat. 

One-half cream cheese must contain not less than 16% butter fat. 

One-fourth cream cheese must contain not less than 8% butter fat. 

All cheese having less than 8% fat must be branded " Skimmed Cheese." 

The term "filled cheese" is commonly appUed to a product in which 
a foreign fat, as oleo oil or lard, has been used. Filled cheese is more 
commonly found in localities where a carefully enforced fat-standard 
law prevails, but, in the absence of a standard for fat in cheese, the manu- 
facturer can cheapen his product much more readily and conveniently 
by selling a skim-milk cheese in place of the whole-milk article, though 
not without producing a sensibly inferior product. 

METHODS OF ANALYSIS. 

Obtaining a Representative Sample. — Method of the A. O. A. Ct — By 
means of a cheese-trier remove, if jaossible, three cylindrical plugs from 
the cheese perpendicular to the surface and in length equal to about half 
the thickness of the cheese, one at the centre, one near the circumference, 
and one midway between the two. About one inch in length is cut off 
from each plug from the end having the rind, and this is discarded. The 
remaining portions of the plugs are then finely divided and mixed as 
intimately as possible. 

In place of the plugs a narrow, wedge-shaped segment may be cut from 
the cheese, reaching from the circumference to the center, the portions 
near tlie rind being removed, and the remainder of the piece being finely 
divided and mixed as before. Analyses should immediately be begun 
after obtaining the sample. 

Determination of Water. — Two or three grams of the sample are 

* Penn. Laws, igoi, Act. 95, p. 128. 

t U. S. Dept. of Agric, Bur. of Chem., Bui. 46, p. 55. 



l6o FOOD INSPECTION AND ANALYSIS. 

carefully weighed in a tared platinum dish, and dried to constant weight 
in an oven at ioo° C. The loss of weight is reckoned as water.* 

Determination of Ash. — Ignite the residue from the moisture determina- 
tion at a low, red heat, cool in a desiccator, and weigh. 

Determination of Fat. — Lyihgoe's Modified Babcock Method. — Weigh 
accurately about 6 grams of the sample in a tared beaker. Add lo cc. 
of boihng water, and stir with a rod till the cheese softens and an even 
emulsion is formed, preferably adding a few drops of strong ammonia to 
aid in the softening and emulsionizing, and keeping the beaker in hot 
water till the emulsion is tolerably complete and free from lumps. 

If the sample is a full-cream cheese, which is usually evident from 
its taste and appearance, a Babcock cream-bottle is employed. The 
contents of the beaker, after coohng, are transferred to the test-bottle 
as follows: Add to the beaker about half of the 17.6 cc. of sulphuric 
acid regularly used for the test, stir with the rod and pour carefully into 
the bottle, using the remainder of the acid in two portions for washing 
out the beaker. Finally proceed as in the regular Babcock test for milk. 
Multiply the fat reading by 18 and divide by the weight of the sample 
taken to obtain the per cent of fat. 

Werner-Schmidt Method. — Boil 2 to 3 grams of the sample in the 
Werner-Schmidt tube (p. 103) with 5 cc. of water and 10 cc. of con- 
centrated hydrochloric acid till, with constant shaking, all but the fat is 
dissolved. Cool, add 25 cc. of ether, and shake the tube well. Draw 
off as much as possible of the ether, after separation, in the usual manner, 
and extract with four or five additional portions of the solvent. 

Distil off the ether from the combined extractions, and weigh the fat. 

Determination of Proteids. — From i to 2 grams of the cheese are 
treated by the Gunning method, adding after partial digestion a piece 
of copper sulphate the size of a pea f to aid in the conversion. NX6.25 
= proteids. 

Separation and Determination of Nitrogen Compounds. — Methods 0} 
Van Slykc. — Twenty-tive grams of the sample are mixed in a porcelain 
mortar with an equal volume of clear quartz sand. Transfer the mix- 
ture to a 450-cc. Erlenmeyer flask, add about 100 cc. of water at 50° C, 
and keep the temperature at 50° to 55° C. for half an hour whh frequent 
shaking. Decant the liquid through an absorbent-cotton filter into a 

* Previously ignited sand or asbestos is recommended by some as an absorbent to be 
placed in the dish, but the writer gets better results in most cases directly as above. 
f Van Slyke, N. Y. Exp. Station, Bulletin 215. 
t N. Y. Exp. Station, Bulletin 215. 



MILK. i6i 

500-cc. graduated flask. Treat the residue with repeated portions of 
100 cc. each of water, heating, shaking, and decanting as above till the 
filtrate, or water extract, at room temperature amounts to just 500 cc. 
exclusive of the fat floating on top, and use aliquot parts of this water 
extract for the various determinations. 

Water-soluble Nitrogen. — Determine the nitrogen by tlie Gunning 
method in 50 cc. of the above water extract, corresponding to 2.5 grams 
of cheese. 

Nitrogen as Paranuclein. — Add 5 cc. of a 1% solution of li)'drochloric 
acid to 100 cc. of the above water extract (corresponding to 5 grams of 
cheese), and keep the temperature at 50° to 55° till the separation is com- 
plete, as shown by a clear supernatant Hquid. Filter, wash the precipi- 
tate with water, and determine the nitrogen therein by the Gunning 
method. 

Nitrogen as Coagulable Proleids. — Neutralize the fiUrate from the 
preceding determination with dilute potassium hydroxide, and heat at 
the temperature of boihng water till the coagulum,* if any, settles com- 
pletely. Filter, wash the precipitate, and determine the nitrogen therein. 

Nitrogen as Caseoses. — Treat the filtrate from the preceding with i cc. 
of 50% sulphuric acid saturated with C. P. zinc sulphate, and warm to 
about 70° C. till the caseoses settle out completely. Cool, filter, wash 
with a saturated solution of zinc sulphate acidified with sulphuric acid, 
and determine the nitrogen in the precipitate. 

Nitrogen as Amides and Peptones. — Place 100 cc. of the water extract 
of cheese in a 250-cc. graduated flask, add i gram of sodium chloride 
and a solution containing 12% of tannin, till the addition of a drop to 
the clear supernatant liquid does not further precipitate. Dilute to the 
250-cc. mark, shake, pour upon a dry fihcr, and determine the nitrogen 
in 50 cc. of the fiUrate, which gives the amount of nitrogen in the 
amido-acid and ammonia compounds. Deduct from this the amount of 
nitrogen as ammonia separately determined, and the difference is the 
amido-nitrogcn. 

Nitrogen as peptones is obtained by subtracting the sum of the amounts 
of nitrogen as paranuclein, coagulable proteids, caseoses, amido-bodies, 
and ammonia from the total nitrogen in the water e.xtract. 

Nitrogen as Ammonia.— Distil 100 cc. of the filtrate from the above 
tannin-salt precipitation into standardized acid, and titrate in the usual 
maimer. 



* According to Van Slyke a precipitate at this point is rare in cheese. 



l62 FOOD INSPECTION /IND ANALYSIS. 

Nitrogen as Paracasein Lactate. — Treat the residue insoluble in water 
(in obtaining the water extract, with several portions of a 5% solution 
of sodium chloride, to form a 500-cc. salt extract of the same, in an 
analogous manner to that employed in preparing the water extract. 
Determine the nitrogen in an ahquot part of this salt extract. 

Determination of Lactic Acid.* — Add water to 10 grams of the cheese 
sample at 40° C. till the volume equals 105 cc. ' Shake and filter. Titrate 
25 cc. of the filtrate (equivalent to 2.5 grams of cheese) with tenth-normal 
sodium hydroxide, using phenolphthalein as an indicator. 

Each cubic centimeter of decinormal alkah is equivalent to 0.009 
gram lactic acid. 

Determination of Milk Sugar. — Boil 25 grams of finely divided cheese 
with two successive portions of about 100 cc. each of water, decant 
through a filter, and finally transfer the residue upon the filter and wash 
with hot water. Make up the entire aqueous extract thus obtained, when 
cold, to 250 cc, and determine the milk sugar by either Fehhng method. 

Detection of Foreign Fat. — The cheese fat, separated in the manner 
described below, is subjected to the various processes detailed under 
butter, in precisely the same way, the fat of cheese being identical with 
that of butter. The most ready means for judging its purity consists 
in determining the refraction with the butyro-refractometer, and the 
Reichcrt number. 

Separation of the Fat for Examination. — Place a quantity, say 25 
grams, of the finely divided sample in a large Erlenmeyer flask, add about 
100 cc. of petroleum ether, cork the flask and allow it to stand for several 
hours with frequent shaking. Decant the petroleum ether through a 
filter, evaporate off the solvent by the aid of heat, and the residue will 
be found to consist of nearly pure fat. 

Or, wrap a sufficient portion of the finely divided sample in a muslin 
cloth, place this in a dish, and heat on the water-bath. The fat which 
runs out is afterward filtered and dried at 100°. 

Suflicient cheese fat may usually be obtained for the refractometer 
reading from the neck of the test-bottle, after completing the Babcock 
test, and, usually (except in the case of skimmed-milk cheese), for the 
Reichert number. 

Detection of Skimmed-milk Cheese. — In a cream cheese the fat 
should greatly exceed the proteids; in a whole-milk cheese the per cent 
of fat should at least equal that of the proteids, and is generally in excess. 

* U. S. Dept. of Agric, Bureau of Chcm., Bui. 46. p. 56. 



MILK. 



163 



If the fat is considerably less than the protcids, the cheese has undoubtedly 
been made from skimmed milk. The following analyses, made in the 
writer's laboratory', illustrate these grades: 



Varieties of Cheese. 


Water. 


Fat. 


Proteids.* 


Ash. 




37-63 
21.89 

55-95 
62.17 
72.80 


47.40 
38.00 
24.00 
15.20 
2.00 


13-7° 
37-7' 
16.49 
21.36 
23-52 


1.27 
2.40 
3-56 
1.27 
1.68 


Whole milk (hard) 


Whole milk (soft) 


Skimmed milk (soft) 

Centrifugally skimmed milk (soft).. 



*By difference. 



REFERENCES ON MILK AND ITS PRODUCTS.* 
Arkman. Milk, its Nature and Composition. London, 1899. 
Conn, H. W. Milk Fermentations. U. S. Dept. of Agric, Off. of Exp. Station, 

Bui. 9. 

Dairy Bacteriology. U. S. Dept. of Agric, Off. of Exp. Station, Bui. 25. 

Conn, H. W., and Esten. The Ripening of Cream. Storrs E.xp. Station, Annual 

Report, 1900. 
DucLAUX, E. Le Lait. Paris, 1894. 
Ellis and Kenrick. Milk and Milk Adulteration. Canada Int. Rev. Dept., Buls., 

21, 28. 
Farrington, E. H., and Woll, F. W. Testing Milk and its Products. Madison, i8g8. 
Fleischmann, W. Lehrbuch der Milchvvirthschaft. Bremen, 1893. 
Gerber, N. Die Praktische Milch-Prucfung. 

Grotenfelt, G. The Principles of Modern Dairy Practice. New York. 
Herz, F. J. Untersuchung der Kuhmilch. Berlin, 1889. 
HussON, C. Le Lait. Paris, 1878. 

Kirchner, W. Handbuch der Milchvvirthschaft. Berlin, 1891. 
Ladd, E. F. Proteids of Cream. Jour. .\m. Chem. Soc, 20, 1898, page 858. 
Le Clerc, J. A. Dairy Products. U. S. Dept. of Agric, Bureau of Chemistry, 

Bui. 65, page 35. 
Leffman, H., and Bean, W. Analysis of Milk and Milk Products. Philadelphia, 1893. 
Lehmann, J., und Hempel, W. Die Milchuntersuchungcn. Bonn, 1894. 
Macf.'VRLANE, T. Milk and Milk Adulteration. Canada Inl. Rev. Dept., Buls. i, 

2, 9> II. 17. 32> 43. 61, 74. So- 

Cheese. Canada Inl. Rev. Dept., Bui. 6. 

Butter. Canada Inl Rev. Dept., Bui. 16. 

McGiLL, .\. Condensed Milk. Canada Inl. Rev. Dept., Buls. 54, 69. 

Otto, A. Die Milch und ihre Produkte. Berlin, 1892. 

Pearmain, T. H., and Moor, C. G. The Analysis of Food and Drugs. Part I. Milk 

and Milk Proteids. London, 1897. 
Pearson, R. A. National and State Dairy Laws. U. S. Dept. of Agric, Bureau of 

An. Ind. Bui. 26, 1900. 
Richmond, H. D. Dairy Chemistr}-. London, 1889. 

* For references on Butter, see p. 458. 



1 64 FOOD INSPECTION AND ANALYSIS. 

Russell, H. L. Dairy Bacteriology. Madison, 1899. 
ScHOLL. Die Milch. 

ScHRODT, M. Anleitung zur Priifung der Milch u. s. w. Bremen, 1892. 
Snyder, H. The Chemistry of Dairying. Easton, 1897. 

Stutzer, a. Die chem. Untersuchung der Kiise. Zeits. f. anal. Chem., i 886, S. 493. 
SwiTHiNBANK, H. Bacteriology of Milk. 1903. 

TouRCHOT, A. L. Milk and Milk Adulteration. Canada Int. Rev. Bui. 53. 
Van Freudenreich, E. Die Bakteriologie in der Milchwirthschaft. Basel, 1893. 
Wanklyn, J. A. Milk Analysis. London. 

Weigmann, H. Die Methoden der Milchkuhserv'irung. Bremen, 1893. 
WmxAKER, G. M. The Milk Supply of Boston and other New England Cities. U. S. 
Dept. of Agric, Bur. of An. Ind. Bui. 26, 1900. 

Alabama Exp. Sta. Bui. 97. Dairy and Milk Inspection. 
Annual Reports of Inspector of Milk and Vinegar, Boston, Mass. 

" " " " " " Cambridge, Mass. 

Arkansas Exp. Sta. Bui. 45. Milk, its Decomposition and Preservation. 
Dairy Products. U. S. Dept. of Agric, Div. of Chem., Bulletin 13, part i, 1887. 
Die Milchzeitung. Bremen, 1872 et seq. 

2. Bacteria in Milk. 

Milk Fermentation and its Relations to Dairying. 
Souring of Milk. 
Facts about Milk. 
Milk as Food. 

Cheese-making on the Farm. 
Keeping Milk in Summer. 
Maine Exp. Sta. Bui. 23 (New Series). Cream Preservation. 
Massachusetts State Board of Health Reports, 1883 et seq. 
Michigan Exp. Sta. Bui. 140. Ropiness in Milk. 

Minnesota Exp. Sta. Bui. 74. Milk and Cheese, Digestibility and Food Value. 
New York (Geneva) Exp. Sta. Bui. 70. Reasons for Changing IMilk Standards. 
" " " " " " 215. Estimation of Proteolytic Compounds in 

Cheese and Milk. 
" (Ithaca) " " " 165. Ropiness in Milk. 

IC 11 II 1' 'I " jgr " " " 

North Carolina Exp. Sta. Bui. 113. Testing of Milk. 

Oklahoma Exp. Sta. Bui. 21. A New Milk Test. 

West Virginia Exp. Sta. Bui. 58. Effect of Pressure in the Preservation of Milk. 

Wisconsin Exp. Sta. Bui. 48. Conn. Culture B. 41, in Butter-making. 

" " " " 52. Babcock vs. Gravimetric Tests for Fat. Acidity in Milk. 

" " " " 54. Restoration of Consistency of Pasteurized Cream. 

" " " " 61. Constitution of Milk with Reference to Cheese Produc- 

tion. 

" " " " 62. Tainted or Defective Milks. 

" " " " 70. Cheese-cunng. 

" " " Annual Reports. 12th et seq. 

Zeitschrift der Fleisch und Milch Hygiene. 



Tne 


" 20. 




29. 




" 42. 




74- 




166. 


nsa 


s Exp. Sta. Bui. 88. 



CHAPTER VII. 
FLESH FOODS. 

MEAT. 

General Structure and Composition. — Meat is structurally made up 
of muscle fibers, held together by connective tissue, through which fat 
cells are usually more or less abundantly distributed. Each muscle fiber 
has a sheath or covering known as sarcolemma, formed of an albuminoid 
substance similar to elastin, and within the fibers are contained the meat 
juices, which are solutions in water of proteids, non-proteid-nitrogenous 
extractives, and salts. The substance of the connective tissue is made 
up largely of the albuminoids elastin (insoluble) and collagen, the latter 
being convertible by boiling with water or treatment with acids into gela- 
tin. The proteids of the meat juices consist chiefly of the globulin mvo- 
sin (by far the most abundant), muscle albumin, and the muscle pigment 
hcemoglobin, or a substance closely analogous thereto. 

In the living muscle there are no peptones, but the ferment pepsin 
is present. After death, by the action of the pepsin in presence of lactic 
acid, a portion of the normal proteids of the muscle undergoes, as it were, 
digestion, so that in meat both peptones and proteoses * are found. 

The non-proteid-nitrogenous extractives are mainly creatin, xanlhin, 
hypoxatilhin, and carnin, which, from their basic character, are known 
as flesh bases. 

The approximate proportions in which the chief constituents are present 
in meat is thus shown by Konig: 

Water -j^, 

■ Sarcolemma (muscle fiber) 13. 

Connective tissue 2. 

Albumin o. 

Creatin o. 

Hypoxanthin o. 

Creatinin 

Xanthin Undetermined 

Inosinic acid 

Uric acid 

Urea o.oi to 0.03 



Nitrogenized compounds. 






to 77.0 





to 18.0 





to !^.0 


6 


to 4.0 


07 


to 0.34 


01 


to . 03 



* A proteose or albumose known as myoalbumose normally exists in the live muscle. 

165 



1 66 FOOD INSPECTION AND AN/i LYSIS. 



Other nitrogen-free compounds. . 



Undetermined 



Fat 0.5 to 3.5 

Lactic acid 0-05 to 0.07 

Butyric acid 

Acetic acid 

Formic acid 

Inosite 

Glycogen ('0.3 to 0.5) 

Salts , ; (0.8 to 1.8) 

Composed of: 

Potash 0.40 to 0.50 

Soda 0-02 to 0.08 

Lime o.or to 0.07 

Magnesia 0.02 to 0.05 

Oxide of iron 0.003 to o.oi 

Phosphoric acid 0.40 to 0.50 

Sulphuric acid 0-003 to 0.04 

Chlorine o.oi to 0.07 

Nitrogen compounds constitute by far the most abundant and im- 
portant portion of the substance of lean meat. Carbohydrates are almost 
entirely lacking, the small amount of glycogen and muscle sugar togethei 
constituting rarely more than i per cent. 

Glycogen (CoHmOj), sometimes called animal starch, is a white, amor- 
phous, tasteless, and odorless substance, when pure, much resembling 
starch. It is soluble in water, forming an opalescent solution, and is 
insoluble in ether and alcohol. With iodine a port-wine color is pro- 
duced, which disappears on heating and reappears on cooling. Glycogen 
is strongly dextro- rotary. It is converted to de.xtrose by boiling with 
dilute mineral acid. 

Muscle Sugar is either entirely absent in the living muscle, or exists 
in traces only. After death it is formed presumably from the glycogen, 
and exists in a very minute quantity, probably as dextrose. 

Inosite (CoHijOj+HjO) is found in traces in the muscular substance of 
the heart, Jiver, kidneys, and testicles. 

Proximate Constituents of the Commoner Meats. — The chief charac- 
teristics of the flesh of various animals are in the main very similar, what- 
ever the nature of the animal. So true is this, indeed, that it is extremely 
difficult from a chemical analysis to distinguish a particular kind of flesh 
when mLxed with that of other animals in finely divided meat preparations, 
such as sausages, potted and deviled meats, and the like. 

The average composition of the commoner cuts of beef, veal, mutton, 
lamb, and pork, as well as of fowl and game, is shown in the following 
tables, compiled from the work of Atwater and Br}'ant,* the accompanying 
diagrams serving to locate, in the case of ordinary meats, the portion of 
the animal from which the meat is taken. 

* U. S. Dept. of Agric, Off. of E.\p. Stations, Bui. 28 (Revised Ed.). 



FLESH FOODS. 




_«6li.(i|)fJ|g-^ 



1. Neck 

1 Chuck 

3. Ribs 

i. shoulder clod 

6, Fore shank. 

6. Brisket 

7. Cross ribs 

8. Plate 



9. Navel 
10. Loin 
IL Flank " 

12. Rump 

13. Round 

14. Second cut round 
1 j. Hind sbaiik 



Fig. 51. — Diagram Showing Cuts of Beef. 
COMPOSITION OF BEEF. 




Cut. 



Num- 
ber of 
Anal- 
yses. 



Refuse 



Water, 



Protein. 



NX 
6.25. 



By 
Differ- 
ence. 



Fat. 



Ash. 



Fuel 

Value 

per 
Pound. 
Cals. 



Chuck: Lean — 

Medium- 
Fat— 

Ribs: Lean — 
Medium- 
Fat— 

Loin : Lean — 
Medium- 
Fat— 

Rump : Lean — 
Medium- 
Fat— 

Round: Lean — 
Medium- 
Fat— 



edible portion. 

as purchased. . 
—edible portion. 

as purchased. . 

edible portion. 

as purchased . . 

edible portion. 

as purchased. . 
—edible portion. 

as purchased. . 

edible portion. 

as purchased. . 

edible portion. 

as purchased. . 
-edible portion. 

as purchased. . 

edible portion. 

as purchased. . 

edible portion. 

as purchased. . 
-edible portion. 

as purchased. . 

edible portion. 

as purchased. . 

edible portion. 

as purchased . . 
—edible portion. 

as purchased . . 

edible portion. 

as purchased. . 



2 
4 

4 
4 
3 
6 
6 
15 
15 
9 



II 

32 

32 

6 

6 

4 

3 

10 

10 

5 

5 

31 

29 

18 

14 

5 

3 



19-S 
15-2 



14-7 
22.6 



20. s 

16.8 



I3-I 

13-3 



14.0 



20.7 
2.3.0 



8.1 

7.2 

12.0 



71-3 
57-4 
68.3 

57-9 
62.3 

53-3 
66.0 
52.6 
55-5 
43-8 
48. 5 
39-6 
67.0 
58.2 
60.6 

52-5 
54-7 
49-2 

65-7 
56.6 

56.7 

45-° 

47-1 

36.2 

70 

64 

65 
60 
60 

54 



3 

9.1 

7-1 



6.6 
II. 9 
10. 1 
18.8 

15-9 
9.8 

9-3 
26.6 
21.2 
35-6 
30.6 
12.7 
II. I 
20.2 

17-5 
27.6 
24.8 

13-7 

11. 

25-5 
20.2 

35-7 
27.6 

7-9 

7-3 

13-6 

12.8 

19-5 

16. 1 



I.O 

0.8 
0.9 

0.8 
0.9 

0-7, 
0.8 
0.7 



0-9 
0.7 
0.7 
0.6 
1.0 
0.9 
1.0 
0.9 
0.9 
0.8 
1.0 
0.9 
0.9 
0.7 
0.8 
0.6 
I.I 
1.0 
I.I 



720 

580 

865 

735 

"35 

965 

79° 

675 

1450 

"55 

1780 

1525 
900 

785 

1 190 

1040 

1490 

1305 

965 

820 

1400 

mo 

1820 

1405 

730 

670 

950 

89s 
1185 
1005 



i68 



FOOD INSPECTION AND AN /I LYSIS. 




1 . Neck 

2. Chuck 

3. Shoulder 

4. Fore ^hank 
6. BreiuC 



6. Ribs 

7. Loin 

8. Flank 

9. Lie 
n.Hln.l shank 




Fig. 52. — Diagram Showing Cuts of Veal. 



COMPOSITION OF VEAL. 



Cut. 



Num- 
ber of 
Anal- 
yses. 



Refuse. 



Water. 



Protein. 



NX 
6.25. 



Bv 
Differ- 
ence. 



Fat. 



Ash. 



Fuel 
Value 

per 
Pound. 

Cals. 



Ribs: 



Fat- 



Chuck: Lean — edible portion. 

as purchased . . 
Medium — edible portion. 

as purchased. . 
Medium — edible portion . 

as purchased. . 

edible portion. 

as purchased . . 

edible portion. 

as purchased. . 
Medium — edible portion. 

as purchased . . 

edible portion. 

as purchased. . 

edible portion. 

as purchased. . 
Medium — edible portion. 

as purchased. . 



Loin: Lean — 



Fat- 
Leg: Lean — 



6 
6 
9 
9 
3 
3 
5 
5 
6 
6 
2 
2 

9 

9 

10 

9 



19.0 



IS. 9 
25-3 



24-3 

22-0 



16.5 



9.1 
14.2 



76.3 
61.8 

73-3 
59-5 
72.7 

54-3 
60.9 
46.2 
73-3 
57-1 
69.0 

57-6 
61.6 



50-4 
73-5 
66.8 
70.0 
60.1 





19 
16 


7 



20 


-7 


IS 

18 


S 
7 


14 


2 


20 


4 


15 


9 


19 
16 


9 
6 


18 


7 


IS 


3 


21 


3 


19 


4 


20 


2 


15 


5 



20.6 
16.7 
19.2 

15-6 

20.1 

iS-o 
18.8 
14.2 
19.9 
15.6 
19.2 
16.0 
18.5 

15-1 
21.2 

19-3 
19.8 
16.9 



1-9 
1.6 

6-5 

5-2 

6.1 

4.6 

19-3 

14-5 

S-6 

4.4 

10.8 

9-0 
18.9 

15-4 
4-1 

3-7 
9.0 

7-9 



1.2 
0.9 

i.o 
0.8 
1. 1 
0.8 
1.0 
0.8 
1.2 
0.9 
I o 

0.9 

1.0 

0.8 

1.2 
I.I 
1.2 

0.9 



465 
380 
640 

5IS 
640 
480 
1 160 
87s 
61S 
480 

825 
690 

II4S 
935 
570 
520 

755 
620 



FLESH FOODS. 



169 




l.Ncck 

2. Chuck 

3. Shoulder 

4. Flank 
S.Loia 
6. Leg 




Fig. 53. — Diagram Showing Cuts of Mutton. 
COMPOSITION OF MUTTON AND L.'VMB. 



Cut. 



Num- 
Vjer of 
Anal- 
yses. 



Refuse. 



Water, 



Protein. 



NX 
6.25. 



By 
Differ, 
ence. 



Fat. 



Ash. 



Fuel 
Value 

per 
Pound. 
Cals. 



Mutton. 

Chuck: Lean — edible portion. 

as purchased. . 

Medium — edible portion. 

as purchased . . 

Fat — edible portion. 

as purchased . . 

Loin: Medium — edible portion. 

as purchased. . 

Fat — edible portion. 

as purchased . . 

Flank: Medium — edible portion. 

as purchased. . 

edible portion. 

as purchased. . 

Medium — edible portion. 

as purchased . . 

Lamb. 

edible portion. 

as purchased . . 

Leg: Medium — edible portion. 

as purchased- . 

Fat — edible portion. 

as purchased. . 

Loin: edible portion. 

as purchased. . 



Leg: Lean — 



Chuck: 



6 
6 

2 

2 

13 



3 

3 

II 



I9-S 



^1-3 



16. 



16.0 
II. 7 



9-9 
16.8 
18.4 



19. 1 
17-4 
13-4 
14.8 



64.7 
52-1 
50-9 
39-9 
40.6 

33-8 
50.2 
42.0 
43-3 
38-3 
46.2 

39-0 
67.4 

56-1 
62.8 

SI-2 
56.2 

45-5 
63-9 
52-9 
54-6 
47-3 
53-1 
45-3 



17-8 


18. 


14-3 


14- 


I5-I 


14. 


II. 9 


II. 


13-9 


13- 


II. 6 


II. 


16.0 


15- 


13-S 


13- 


14-7 


14- 


13-° 


12. 


15.2 


14- 


13-8 


13- 


19.8 


19. 


lO.S 


IS- 


18.5 


18. 


15-I 


14. 


19. 1 


19. 


15-4 


15- 


19.2 


18. 


15-9 


15- 


18.3 


17- 


15-8 


14-! 


18.7 


17- 


16.0 


i5-< 



16.3 

I3-I 

33-6 
26.7 

44-9 
37-5 
33-1 
28.3 
41.7 
36.8 
38-3 
36-9 
12.4 

i°-3 
18.0 
14.7 

23.6 
19. 1 
16-5 
13-6 
27.4 

23-7 
28.3 
24.1 



0.9 
0.8 
0.9 
0.6 
0.8 
0.7 
0.8 
0.7 
0.8 
0.7 
0.7 
0.6 
1.1 
0.9 
i.o 
0.8 

1.0 
0.8 
I.I 
0.9 
0.9 
0.8 
1.0 



1020 
820 
1700 
1350 
215s 
1800 

1695 

1445 

2°35 

1795 

1900 

1815 

890 

740 

1105 

900 

135° 
1090 

1055 
870 

1495 
129s 
1540 
1315 



lyo 



FOOD INSPECTION AND ANALYSIS. 



-n 


7 


3 8 


^^\ 


2 




4 


/ ' A 




5 


>. / 


Jill ^-^ 7/" Vi* «icl 






1. 


Head. 




2 


Shoulder. 




3. 


Back. 




4. 


Middle cut. 




S. 


Belly. 




6. 


Ham. 






Y. 


Ribs. 






8. Loin. 



Fig. 54. — Diagram Showing Cuts of Pork. 
COMPOSITION OF PORK, POULTRY, .A.ND GAME. 





Num- 
ber of 
Anal- 
yses. 


Refuse. 


Water. 


Protein. 


Fat. 


Ash. 


Fuel 


Cut. 


NX 
6.25. 


Differ- 
ence. 


per 
Pound. 
Cals. 


Pork. 

Shoulder: edible portion . . 

as purchased. . . 

Loin: Lean — edible portion . . 

as purchased. . . 

Fat — edible portion.. 

as purchased . . . 

Ham: Lean — ■ edible portion. . 

as purchased. . . 

Fat — edible portion . . 

as purchased. . . 

Poultry and G.ame. 
Chicken : edible portion . . 

as purchased. . . 
Fowl: edible portion. . 

as purchased. . . 
Goose: edible portion . . 

as purchased. . . 
Turkey: edible portion. . 

as purchased. . . 
Quail: as purchased. . . 


19 
19 

I 
I 
4 
4 
2 
2 
5 
5 

3 

3 

26 

26 

I 
I 
3 
3 

I 


12.4 
23-5 

'Vt.'s 
0.9 

13-2 

41.6 
25-9 

'\y.h' 

22.7 


51-2 
44-9 
60.3 
46.1 
41.8 
34-8 
60.0 
59-4 
38-7 
33-6 

74.8 
43-7 
63-7 
47-1 

46.7 

38-S 

S.S-S 
42.4 
66.9 


13-3 
12.0 
20.3 

15-5 
14-S 
II. 9 
25.0 
24-8 
12.4 
10.7 

21-5 
12.8 

19-3 
13-7 
16.3 
13-4 
21. 1 
16. 1 
21.8 


13-8 
12.2 
19.7 

I3-I 
10. 9 

24-3 

24.2 

10.6 

9.2 

21.6 
12.6 
19.0 
14.0 
16.3 

13-4 
20.6 

15-7 


34-2 
29.8 
19.0 
14-5 
44-4 
37-2 
14.4 
14.2 
50.0 
43-5 

2-5 

1-4 
16.3 
12.3 
36.2 
29.8 
22.9 
18.4 

8.0 


0.8 
0.7 

I.O 

0.8 
0.7 
0.6 
1-3 
1-3 
0.1 

°-5 

I.I 
0.7 
1.0 
0.7 
0.8 
0.7 
1.0 
0.8 
1-7 


1690 

1480 

I180 

900 

2145 
1790 

1075 
1060 

2345 
2035 

505 

295 

1045 

775 
1830 

1 50s 
1^60 

107s 
775 



FLESH FOODS. 171 

Characteristics of Sound Meat. — The reaction of meat should be acid. 
If neutral or alkaline, decomposition is indicated, except that alkalinity 
may be due to the use of alkaline salts as preservatives. 

Letheby * gives the following characteristics of sound, fresh meat. In 
color it is neither pale pink nor deep purple, the former indicating that 
the animal was affected with some disease, and the latter that it died a 
natural death, and was not slaughtered. In appearance it is marbled, 
due to the presence of small veins of fat distributed among the muscles. 
In consistency it is firm and elastic to the touch, and should hardly moisten 
the finger; a wet, sodden, or flabby consistency with a jelly-like fat is 
indicative of bad meat. As to odor, it is practically free ; whatever odor 
there is should not be disagreeable; a sickly or cadaverous smell is indica- 
tive of diseased meat. After standing for a day or so, it should not become 
wet, but on the contrary should grow drier. When dried at 100° C. it 
should not lose more than 70 to 74 per cent in weight; unsound meat 
frequently loses 80% or more. It should shrink very little in cooling. 

Inspection of Meat. — While carefully drawn laws exist almost every- 
where relating to the sale of meat, and government inspectors are ap- 
pointed to carry out the requirements of the laws, yet in this country there 
is undoubtedly some meat unfit for food on the market, owing to the 
small number of inspectors, and the consequent comparative safety with 
which unscrupulous dealers may sell meats forbidden by law and escape 
detection. A far more rigid system of meat inspection is in force in 
Europe than in the United States, especially in Germany. 

Unwholcsomeness 0} Meat may be due to a diseased condition of the 
animal while ahve, or to poisonous or injurious toxins developed by 
the action of bacteria after death. In the first case, the diseased conditions 
may be due to temporary causes only, or to the presence of animal parasites, 
such as trichincT in pork, or as the result of pathogenic bacteria, causing 
such serious diseases as tuberculosis, anthrax, glanders, etc. It thus 
requires much skill and judgment on the part of the meat-inspector 
to correctly pass upon the suitability for food of the various meats as 
they appear on the market. Coplin and Bevan f give in detail useful 
data regarding the inspection of meat, as well as of the animal before 
slaughtering, showing the requisite size, weight, age, conditions of health 
etc., that should obtain. The detailed physical and microscopical exami- 
nation involved in such inspection is, however, rarely germane to the 
work of the public food analyst, and wiU not be treated of in this manual. 
♦Lectures on Food, p. 210. t Practical Hygiene, pp. 130-157. 



172 FOOD INSPECTION AND ANALYSIS. 

It is also beyond the scope of the present work to treat of the harmful 
toxins developed by bacterial action in meat and fish, causing what is 
known as ptomaine poisoning. The work of detecting and isolating 
such poisons comes within the province of the bacteriologist and biolo- 
gist, rather than that of the chemist, involving many experiments upon 
guinea-pigs, rabbits, or other animals not usually found in the chemist's 
laboratory. It has furthermore been recently shown by Vaughn and 
Novy * that even when these toxins are present in foods in sufficient 
quantity to produce serious resuhs, very considerable amounts of the 
food must be taken in order to isolate them by chemical means, more, 
in fact, than is usually available for analysis. 

For the general inspection of meats for animal parasites, poisonous 
toxins, etc., the reader is referred to such works as those of Vaughn and 
Novy, Fischoder, Walley, Andrews, Cobbold, and Salmon as cited in the 
references on page 202. 

U. S. Standards.! — Standard Meal is any sound, dressed, and properly 
prepared edible part of animals in good health at the time of slaughter. 
The term "animals" as herein used includes not only mammals, but 
fish, fowl, crustaceans, mollusks, and all other animals used as food. 

Standard Fresh Meal is meat from animals recently slaughtered, or 
preserved only by refrigeration. 

Standard Sailed, Pickled, and Smoked Meals are unmixed meats pre- 
served by salt, sugar, vinegar, spices, or smoke, singly or in combination, 
whether in bulk or in packages. 

Standard Mamijaclured Meats are meats not included in the above 
divisions, whether simple or mixed, whole or comminuted, with or without 
the addition of salt, sugar, vinegar, spices, smoke, oils, or rendered fat, 
if they bear names descriptive of their composition, and when bearing such 
descriptive names, if force or flavoring meats are used, the kind and 
quantity thereof are made known. 

■ Preservation of Meat. — Raw meat soon begins to decompose, unless 
precautions are taken to destroy, or at least check the growth of putrefying 
bacteria. From earhest times the subjection of meat to extreme cold 
has been practiced in order to enhance its keeping qualities. Bacterial 
growth is inhibited to a greater or less extent by refrigeration, by sub- 
jecting the meat to the various processes of curing, by the use of high 
temperatures and the exclusion of air as in canning, and by the employ- 
ment of antiseptics. 

* Cellular Toxines. f U. S. Dept. of Agric, Off. of Sec, Circ. No. lo. 



FLESH FOODS. I73 

Refrigeration may consist (i) in actually freezing the meat, in which 
condition it may be kept without decomposition almost indefinitely, until 
finally thawed for use, or (2) in keeping the meat at or near the temperature 
of freezing without actually congealing it, as is done by the use of the 
ordinary refrigerator. The second method, while much less efficacious 
than the first, serves to prevent decomposition for a considerable time; 
it furthermore does not impair the flavor of the meat to any such extent 
as the method of actual freezing. 

Curing consists in subjecting the meat to various processes of drying, 
smoking, pickling, corning, etc., or to a combination of these processes. 
In simple drying, the meat is subjected to the heat of the sun or to artificial 
heat. In smoking, which is commonly practiced on beef and ham, the meat, 
which may or may not be first salted or otherwise treated, is exposed for 
some time to the smoke of burning beech or hickory wood, during which 
it becomes to some extent impregnated with the antiseptic properties of the 
creosote and pyroligncous acid, at the same time being dried by the heat 
of the burning wood. In some cases best results are obtained by a slow 
smoking at a comparatively low temperature, while in others quick, hot 
smoking is found most efficacious. The character of the meat is decidedly 
changed by smoking, and, according to Utescher, smoked meat is always 
alkaline in reaction. In pickling^ the meat may be treated with dry 
salt and subjected to pressure, so that the meat juice forms the liquid 
for the brine, in which it is allowed to remain for some time; or, as in 
the ordinary process of corning, the beef is soaked for some days in a 
strong solution of salt to which a little saltpetre (KNO3) has been added. 
In the process of pickhng, the salts from the brine slowly diffuse into 
the interior of the meat by osmosis, a part of the soluble albumin passing 
out into the brine. The effect of the saltpetre is to preserve the natural 
red color of the meat, which by the action of salt alone becomes destroyed, 
or at least impaired. 

Bacon and ham are frequently cured by pickling in brine containing 
salt, saltpetre, and cane sugar, and sometimes also such antiseptics as 
boric acid and calcium bisulphite. A common pickhng fluid used for 
this purpose consists of 55 lbs. salt, 5 lbs. saltpetre, 5 lbs. antiseptic (boric 
acid), and 5 lbs. cane sugar, in sufficient water to make up 20 gallons. 

The curing of bacon is sometimes effected by injecting the pickling 
fluid into the tissues with a "pickle-pump," capable of exerting a pressure 
of 40 lbs. to the square inch, and provided with a hollow, perforated needle- 
nozzle, which penetrates the flesh. After pickhng, the bacon or ham 



174 FOOD INSPECTION AND ANALYSIS. 

may be simply dried, or, if desired, smoked. Oak sawdust is frequently 
burned for the smoking of ham. 

The Use of Antiseptics in Meat. — Most of what might be termed 
the modern preservatives are to be looked for in one or another of the 
various meat preparations, though some are better adapted than others 
for use in particular cases, as will be seen by reference to the composition 
of typical commercial preservative mixtures given on page 663. 

Boric Acid and Borax, usually in mixture, are by far the most popular 
and widely used preservatives in connection with meat. Like salt, they 
are used commonly in surface application, in the case of large cuts of meat, 
or by mixing, in the case of sausage meat. A more recent method of 
apphcation consists in impregnating the tissue of the meat with a solution 
of the boric mixture, by means of the above-described pickle-pump. In 
the curing of bacon, boric acid and borax are of late being used, to 
displace part of the salt, thus yielding, it is claimed, a softer, fresher, and 
more palatable product. 

Sulphurous Acid. — As much as 1% of a solution of sulphurous acid may 
be added to meat without being apparent to the taste or smell. Mitchell 
quotes Fischer as having found that 50% of the preserved meat products 
(sausages, etc.) sold in Breslau in 1895 contained sulphites, varying in 
amount from o.oi to 0.34 per cent of sulphur dioxide. Calcium bisulphite 
is a salt commonly employed. 

Salicylic Acid is not of such common occurrence in meat products 
as the other antiseptics mentioned. The writer has found it in prepared 
mince-meat. 

The toxic effects of the presence of these and other antiseptic chemi- 
cals in meats, and the most practical means of controlling their use are 
questions in controversy, presenting no new phases that have not been 
elsewhere discussed in treating of the general question of preservatives 
in food. Methods of detecting preservatives in meats are given elsewhere. 

Effect of Cooking on Meat. — The general result of cooking is to render 
the meat less tough, to develop an agreeable flavor, and to coagulate more 
or less of the albuminoids. When subjected to moist heat, such as boil- 
ing and steaming, some of the soluble materials are dissolved, so that 
when the liquor in which the meat is boiled is thrown away, some of the 
valuable substances are lost. This is especially true when meat is placed 
in cold water which is afterwards brought to boiling, a method to be 
recommended when the liquor with the dissolved extractives is to be 
used for broth. When the meat to be boiled is placed at once in boil- 



FLESH FOODS. 175 

ing water, there is less loss of soluble matter by reason of the formation 
of a more or less impenetrable coating on the outside, by the coagulation 
of the albuminoids. Meat that is boiled becomes softer, owing to a par- 
tial dissolving of the gelatin formed. In the dr}' cooking of meat, as 
by broiling or roasting, there is usually a hardening of the tissues, and 
a driving out of some of the meat juices, which are however, often recovered 
in the form of gravies. 

Canning of Meat. — By far the most effective method of preser\-ing 
meat and meat preparations of all kinds for long periods of time con- 
sists in the application of the jirinciple of sterilizing by heat, and sealing 
in air-tight cans. The process of canning cooked meat and its products 
does not differ materially from that employed in the similar preparation 
of vegetables. (See Chapter XIX.) Previous to canning, the meats 
are usually cooked by roasting, boiling, or steaming, during which process 
the changes described in the preceding paragraph take place. 

Many brands of canned beef, veal, tongue, ham, chicken, fowl, and 
game found on the market are honest preparations, and true to the 
names on their labels. On the other hand, there are constantly to be 
found examples of substitution of one meat for another, especially in 
spiced or highly seasoned chopped mixtures. Many varieties of the 
so-called potted and devilled meats and game, for example, often con- 
sist wholly or in part of a much cheaper variety than that specified on 
the label. The substitution of the fat of cheaper grades of meat, such 
as that of beef and pork in pates and purees of fowl and game, is also 
common. Indeed, it is largely among the canned meats and prepared 
meat products that instances of adulteration are to be found, since the 
fresh meats in whole cuts, excepting in so far as treatment with preser- 
vatives is concerned, rarely come into the hands of the food analyst for 
examination as to purity. 

Preservatives are sometimes added to canned meats, especially in 
the case of dried and smoked beef, ham and bacon, and in the potted 
and devilled mixtures. Boric acid, benzoic acid, and sulphites have 
been found in these preparations. 

Composition of Canned Meats. — The following table, compiled from 
results published by Bigelow and others,* shows the composition of 
various of the most common canned and preserved meats and meat 
products, and in one or two instances fresh meat has been included for 
comparison. 

* U. S. Dept. of Agric, Bur. of Chem., Bulletin 13, part 10. 



176 



FOOD INSPECTION AND ANALYSIS. 







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FLESH FOODS. 



177 



Sausages. — Nature and Composition. — Sausages are made from finely 
chopped meat, highly seasoned with various spices, and, as usually sold, 
stuffed into casings made of the cleaned and prepared intestine-skin of 
cattle, sheep, or hogs. The meat most commonly used is pork. Sau- 
sages are frequently home-made, especially in farm communities, the 
chopped and seasoned meat being stuffed in cloth bags instead of casings. 
Any and all kinds of meat are used in sausages, and much that is 
undesirable and even unwholesome is undoubtedly most readily used up 
in this product. There is little doubt that horse meat occasionally 
gets into the hands of the markctmen to be worked up in the form 
of sausages mi.xed with other meat. Sausages are sometimes artificially 
colored, and in some cases contain so-called "fillers" in the nature of 
dried bread, com and potato starch, crackers, waste biscuit, boiled rice, 
etc. The alleged use of these fillers is for the purpose of absorbing 
moisture, but they are undoubtedly used as cheapeners. 

CHEMICAL COMPOSITION OF SAUSAGES.* 





No. of 
Analy- 
ses. 


Ref- 
use. 


Water. 


Protein. 


Fat. 


Total 
Carbo- 
hy- 
drates. 


Ash. 




Kind. 


NX6.25 


By 
Differ- 
ence. 


Fviel 
Value, 
Cals. 


Farmer: edible portion. . . 

as purchased 

Pork: as purchased 

Bologna: edible portion 

as purchased 

Frankfort :as purchased 


I 

I 

II 

8 

4 
8 


3-9 
3-3 


23.2 
22.2 
.39-8 
60.0 

55-2 
57-2 


29.0 
27.9 
I3-0 

18.2 
19.6 


27.2 
26.2 
12.7 
18.4 
18.0 
19.7 


42.0 
40.4 
44-2 
17.6 
19.7 
18.6 


1. 1 
°-3 

i-i 


7-6 

7-3 
2.2 

3-7 
3-8 
3-4 


2310 

2225 
2125 

1095 
1 1 70 
1 170 



*U. S. Dept. of Agric, Off. of Exp. Stations, Bui. 28 (Revised Ed.). 



Artificial Coloring Matter in Sausages. — Owing to the rapid color 
changes which freshly chopped meat, especially beef and mutton, natu- 
rally undergo, it is a common practice to employ powdered nitre or salt- 
petre to preserve the fresh color. As much as 4 ounces of nitre to 100 lbs. 
of meat is sometimes used. A larger quantity would result in a shriveled 
appearance. The use of artificial colors is also common, in order to 
permanently dye the flesh a bright red, similar to the tint which the oxy- 
haemoglobin naturally imparts to the beef, when fresh. A variety of colors 
are employed for this purpose, such as red ochre, coal-tar dyes, cochineal, 
etc. 



lyS FOOD INSPECTION AND ANALYSIS. 

ANALYTICAL METHODS. 

In analyzing meats and meat products due regard must be paid to 
their perishable nature, and, for this reason, immediately after their 
receipt by the analyst the various determinations should, if possible, be 
promptly begun and rapidly carried out. If delays are absolutely necessary, 
the samples, as well as some of the solutions, especially during the earlier 
course of the analysis, should be kept on ice to prevent decomposition. 
Refuse material, such as bones, skin, gristle, etc., are separated as com- 
pletely as possible by means of a knife from the edible portion, and the 
latter, cut first into small pieces, is passed through a sausage-machine 
or ordinary household meat-chopper, in order to reduce to a homogeneous, 
finely divided mass. 

Determination of Water. — From i to 3 grams of the finely divided 
material are weighed in a tared platinum dish, and dried to constant 
weight at a temperature of 100° C. in an air-oven. A slight oxidation 
of the fat may introduce a trifling error, but, excepting for the most exact 
work, where the drying should be accomplished in an atmosphere of 
hydrogen, or in vacuo, the above method is sufficiently close. 

Determination of Ash. — The residue from the total solids is incinerated 
in the original dish over the free flame at a low red heat, or in a muffle, 
adding if necessary, at intervals, a very little powdered ammonium nitrate. 
A perfectly white ash is difficult to obtain. 

Determination of Fat. — About two grams of the sample are carefully 
weighed in a tared Schleicher-and-Schull Soxhlet shell, which, after drying 
in tlie air-oven at 100°, is transferred to an extraction apparatus a.nd sub- 
jected to continuous extraction for at least sixteen hours with anhydrous 
ether, or pure petroleum ether. It is impossible to extract all the fat in 
this manner, but the approximate result obtained is as a rule accepted, 
since complete extraction involves digestion of the nitrogenous matter 
v/ith pepsin, and intermittent treatment with the solvent, a process both 
tedious and open to other sources of error. 

In case a special examination of the fat is to be made, a large portion 
of the original finely divided sample is shaken with petroleum ether in a 
corked flask and allowed to macerate for some hours or over night. The 
solvent is then poured off, and tlie fat is left after evaporation. In the case 
of mixed canned-meat preparations, it is often desirable to determine the 
character of the fats as a possible clue to the variety of meat used. For 
this purpose the regular methods prescribed under oils and fats (Chapter 
XII) are used. 



FLESH FOODS. 



179 



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i8o FOOD INSPECTION AND ANALYSIS. 

Determination of Total Nitrogen. — Two grains of the sample are 
treated according to the Gunning method (page 6i). If by a qualitative test 
nitrates are present (as in the case of corned beef and similar preparations), 
the modified Gunning method, including the nitrogen of nitrates, is em- 
ployed (page 63). While in the case of meat the time-honored custom of 
representing the total protein or nitrogenous substances by NX6.25 is by 
no means strictly accurate, considering the wide variation in nitrogenous 
content of the various compounds present, a fairly close approximation to 
the total nitrogenous substance present is obtained by using this factor, 
since the proteids form by far the largest group of all. The factors to be 
cmploved in the calculation of the flesh bases are given elsewhere (page 184). 

Separation and Examination of Nitrogenous Bodies. — Just how far the 
analyst should subdivide the various nitrogenous bodies present in meat 
depends largely on the importance of the case in hand. Frequently the 
simple determination of total nitrogen as above is sufficient. It is rarely 
necessary to go further than to divide the nitrogenous bodies into several 
main groups, according to their solubility in water or other solvents, and 
their behavior toward certain reagents. 

Knorr's Method * consists in extracting a weighed portion of the 
finely divided, fat-free sample with strong alcohol, which dissolves the 
meat bases, but not the proteids. With the meat bases are also dissolved 
of course the minute quantity of lactic acid, inosite, and glycogen which 
the meat contains. The alcoholic extract is dried and weighed, and the 
nitrogen determined in the residue from this extraction. A fresh portion 
of the sample is then extracted repeatedly with cold water, which removes 
both the soluble albumin and the meat bases. The residue from the 
water extract is then dried at 100° and weighed. On filtering the 
cold-water extract, and heating the filtrate to boihng, the coagulated 
albumins are precipitated from the solution containing the meat bases, 
and are fiUered oil, the precipitate being washed and dried at 100°. 

Knorr's average results of eleven analyses of meat are as follows: 
Dried residue from cold-water extract (representing nitrogenous 

principle of muscle fiber and sheaths) 13 - 76% 

Dried soluble albumin (coagulated by heating and filtered from 

cold water extract) 2 .24% 

Total cold-water extract (dried and weighed) 3 - 56% 

Total nitrogen in sample 3-37% 

Nitrogen in residue from alcohol extraction • 2 .86% 

Alcoholic extract (dried and weighed) 3 • °3% 

* Report of U. S Dept. of .\gric., 1886, pp. 355-357- 



FLESH FOODS. l8i 

The nitrogen may be determined separately in each of these classes, 
and by the approximate factor the corresponding nitrogen substance, or 
class of substances ascertained. 

General Scheme for Separation. — In order to separate most completely 
the various classes of nitrogenous bodies found in meat, a portion of the 
fat-free sample should first be exhausted with cold water, which removes 
the soluble proteids (albumin, proteose, and peptones), leaving behind the 
insoluble globulins, the sarcolemma, the albuminoids of the connective 
tissue (clastin, etc., also insoluble), and the collagen. By next exhausting 
with boiling water the collagen is removed in the form of soluble gelatin. 

By treatment of the combined aqueous extract with bromine, or with 
zinc sulphate, or with phosphotungstic acid, in the manner hereafter 
explained, the proteids in solution, including the proteose, peptones, and 
gelatin, are precipitated, leaving in solution the meat bases. 

In obtaining the results from which the table on page 176 was com- 
piled,* but three divisions of nitrogenous substances were made, viz., 
(i) those insoluble in hot water; (2) those precipitated from the water 
extract by bromine; and (3) the flesh bases. 

Nitrogenous Substance oj the Meat Fiber. — About 2 grams of the 
finely divided sample accurately weighed, are first extracted with ether, 
and, after boiling in water for some minutes, the mixture is transferred 
to a Gooch crucible or filter-plate, and further extracted with hot water till 
all soluble matters are removed. Determine the nitrogen in the insoluble 
residue by the Gunning method. NX 6.25= the nitrogenous substance 
of the meat fiber, including the coagulated proteids and globulins. 

If the sample is first thoroughly exhausted with cold water before the 
hot-water extraction as above, the coagulable albumin is removed, and, 
if it is desired, the nitrogen may be separately determined in the cold- and 
hot-water extracts, thus separating the albumin from the gelatinoids.f 

Determination oj Proteoses, Peptones, and Gelatin.l — The entire fil- 
trate from the meat fiber containing all the water-soluble extractives, as 
obtained in the preceding paragraph, is evaporated to small volume. 

* U. S. Dept. of Agric, Bur. of Chem., Bui. 65; also Bui. 13, p. 1396. 

t The difference between direct extraction with hot water and successive extraction 
first with cold water and then with hot should be clearly borne in mind. If treated at once with 
hot water, the albumin is coagulated and left behind in the meat with the meat fiber and 
globulins, while the collagen is rendered soluble and removed. By cold-water extraction 
at the beginning, the albumin is removed and the collagen left behind. Treatment first 
with cold and then with hot water is the only means of removing all water-soluble material. 

J U. S. Dept. of Agric, Division of Chemistry, Bulletin 54. 



1 82 FOOD INSPECTION AND ANALYSIS. 

If cold water is first used for extraction before treatment with the hot 
water, a turbidity will result on heating, due to coagulation of the albumin. 
In this case the extract should be filtered, the clear solution transferred to 
a Kjeldahl flask and acidulated strongly with hydrochloric acid, after 
which 2 cc. of liquid bromine are added and the contents thoroughly 
shaken. If, after shaking, all the bromine has been absorbed, more 
should be added, so that after saturation two or three drops of bromine 
are left undissolved. Allow the mixture to stand over night, during which 
all the precipitate will have settled out. Decant the supernatant liquid 
through a filter, and wash the residue in the flask by shaking several 
times with added water, depending upon the excess of bromine to saturate 
the wash-water, and decanting the wash-water through the filter. Finally 
return the filter to the original flask with the washed residue, and determine 
the nitrogen by the Gunning method. Nx 6. 25 = combined proteose, 
peptone, and gelatin. This method does not give absolutely accurate 
results, owing to the fact that bromine does not completely precipitate 
all the proteose and peptone. The method is convenient on account 
of its simplicity, and is undoubtedly approximately correct. 

Wilefs Improved Method* — After evaporation of the water extract, 
and filtration, if necessary as described in the preceding paragraph, add 
two or three drops of dilute sulphuric acid and saturate the solution with 
powdered zinc sulphate, f avoiding an excess. Each 50 cc. of solution 
require about 80 grams of the salt. Allow the coagulated proteids to 
settle out, filter, and wash with a saturated solution of zinc sulphate. 
The filtrate from the treatment with zinc sulphate is then acidulated with 
hydrochloric acid in a Kjeldahl flask, treated with bromine, and the 
process described in the preceding paragraph carried out, adding the 
zinc sulphate precipitate to the residue precipitated by bromine in the 
Kjeldahl flask, and determining the nitrogen in the whole. 

Mallet's Phosphotungstk-acid Method.X — It was originally stated by 
Stutzer that phosphotungstic acid completely precipitates the proteids 
and allied substances, while the amides or flesh bases are not precipitated. 
This is found, however, not to be strictly true, as the peptones are only 
incompletely precipitated, and many of the amido-bodies are precipitated 
by phosphotungstic acid in the cold, but redissolve on heating, or on the 
addition of hot water. Thus, betaine is soluble, i part in 71 parts of 

* U. S. Dept. of Agric, Bureau of Chemistry, Bui. 65, p 11. 

t Boemer, Zeits. fiir anal. Chcm., 1895, 34, 562. 

J U. S. Dept. of Agric, Bulletin 54, Div. of Chem., p. 22. 



FLESH FOODS. ■ 183 

water at 98.2° C; creatin, i part in 107 parts at 98.1° C; creatinin, 
I part to 222 at 97.9°; hypoxanthin, i to 98 at 97.6°, etc., though all of 
these are precipitated by phosphotungstic acid. 

Mallet's method is based on the principle that amido-bodies, by pre- 
cipitating with phosphotungstic acid and washing the precipitate with 
hot water, can be separated from all proteid-hkc bodies excepting peptones. 
These last are, however, precipitated by tannic acid, hence the separation 
can be made complete. 

The combined cold- and hot-water extract from the meat fiber is 
heated to 90° C, acidified with acetic acid, and filtered free from coagulum 
(albumin), which is washed with hot water. While still hot, a shght 
excess of tannic acid is added to the filtrate, which precipitates the 
peptones and gelatin.* Cool, filter, and wash with cold water. 

The filtrate from the peptones is heated again nearly to boiling, and 
a solution of phosphotungstic acid. Reagent No. 20, is added as long 
as a precipitate continues to form, avoiding, however, a large excess. The 
precipitate is washed by hot water upon a filter, and the washing continued, 
taking care that the temperature of the water does not fall below 90° C. 

If it is desired to separate the albumin from the other proteids, and 
the peptones and gelatin from the proteoses, the nitrogen may be separately 
determined in the three precipitates ; otherwise the three are combined, and 
the nitrogen determined in all together. In either case the filters with 
their contents should be introduced into strong sulphuric acid as soon as 
possible after washing to avoid loss by decomposition. The factor 6.25 is 
employed. 

Determination of Gelatin. — Modified Stiitzer^s Metlwd.t — A weighed 
portion of the sample, say 10 grams, is thoroughly extracted by boiling 
water, the extract transferred to a porcelain dish containing about 
20 grams of previously ignited sand, and evaporated to dryness. The 
residue is then stirred with four successive portions of absolute alcohol, 
using about 50 cc. each time and pouring it oS through a filter consist- 
ing of a layer of asbestos fiber on a perforated porcelain plate within a 
funnel. This funnel is surrounded by chopped ice, and is so arranged 
that gentle suction may be used to hasten the filtration. The residue is 
then repeatedly stirred with successive portions of about 100 cc. each of 
a mixture containing 100 cc. of 95% alcohol, 300 grams of ice, and 600 

♦Peptones are not completely precipitated by phosphotungstic acid, but according to 
Halliburton their precipitation by tannic acid is complete. 
t U. S. Dept. of Agric, Bui. 13, part 10, p. 1397. 



184 



FOOD INSPECTION AND AN/t LYSIS. 



grams of cold water, the portions being passed through the asbestos fiUer, 
and the washing being continued till the solution is colorless as it comes 
from the filter, keeping the temperature always below 5°. The asbestos 
is then transferred to a beaker with the washed residue, and the whole 
thoroughly extracted with boiling \yater. The hot-water extract is evap- 
orated to small volume, and washed into a Kjeldahl flask, in which it is 
then evaporated to dryness, and the nitrogen determined by the Gunning 
method: Nx 5.55 = gelatin. 

Determination of Flesh Bases. — From the total nitrogen, determined 
in a portion of the original sample, is deducted the sum of the nitrogen 
found in the extracted meat fiber and that of the combined albumin, 
proteose, peptone, and gelatin. The difference is the nitrogen of the 
flesh bases, which, muhiplied by 3.12, expresses the percentage of flesh 
bases calculated as creatin. 



FACTORS CORRESPONDING TO FLESH BASES.* 



Substance 

Creatin 

Creatinin 

Xanthin 

Xanthocreatinin 

Hypo.xanthin 

Carnin 

Leucin 

Tyrosin 

Urea 

Uric acid 



Formula. 



Proportion of 

Nitrogen. 



Factor. 



C.H^N^I, 

C.HjNjI 

QH.N.O, 

C5H,„N,0 

CsH.N.O 

C,H,N,03 

C,H„NO, 

C,H„N03 

CHjNjO 

C,H,N.03 



42 in 131 
42 in 113 
56 in 152 
56 in 142 
56 in 137 
56 in ig6 
14 in 131 
14 in 181 
28 in 60 
56 in 168 



3-12 
2.69 
2.71 
2-54 
2-44 
3-5° 
9-36 
12.93 
2.14 
3.00 



* Allen's Com. Org. Analysis, Vol. IV, p. 308. 

Detection of Nitrates. — A small portion of the finely divided mate- 
rial is treated in a porcelain dish or on a tile with a little i% solution 
of diphenylamine in concentrated sulphuric acid. Presence of a blue 
color indicates a nitrate. 

Detection of Preservatives. — Meats may be systematically tested for 
preservatives in the same manner as canned goods. The presen'atives most 
commonly used in meat and meat preparations are tested for as follows : 

Detection 0} Sulphurous Acid. — Distill a quantity of the finely divided 
sample in water mixed with phosphoric acid. The first 10 cc. of the dis- 
tillate are resented and treated, first with an excess of iodine or bromine, 
and second with barium chloride. A precipitate indicates sulphurous 
acid. The process may be carried out quantitatively. 



FLESH FOODS. 185 

Detection oj Boric Acid. — A portion of the finely divided meat, mechan- 
ically freed from fat as far as possible, is warmed with water acidified with 
hydrochloric acid, and turmeric-paper is soaked in the extract. The 
rose-red color of the turmeric-paper after drying (turned olive by weak 
alkali) is indicative of boric acid. 

A more delicate method of procedure consists in burning to an ash 
a portion of the meat, after treatment with lime water, and testing with 
the turmeric-paper a solution of the ash slightly acidified with hydro- 
chloric acid. 

Detection 0} Salicylic Acid. — ^The sample, mechanically freed from 
fat, is slightly acidified and shaken out with ether. The ether extract 
evaporated to drj-ness is tested with a drop of a solution of ferric chloride. 
A deep-violet coloration indicates salicylic acid. 

Starch in Sausages. — Detection. — The addition of cracker or bread 
crumbs is best indicated by the presence of considerable starch, which 
is readily recognized by the iodine test, applied by boiling up a portion 
of the sample with water, cooling and adding a drop of iodine reagent 
to the liquid. The characteristic blue color is produced if starch be 
present in notable quantity. One per cent or more of starch present 
may be due to the pepper and spices used in seasoning the sausage. A 
small admixture of starch is rendered apparent when a thin section of 
the sausage is treated with a drop of iodine reagent and viewed under 
the microscope. A microscopical examination will also reveal the char- 
acter of the starch, whether it is from cereals or from pepper. 

Estimation of Starch. — The regular acid conversion process, p. 223, may 
be applied, but more accurate results are obtained by the method of 
inversion with malt extract. Medicus and Schwab * prepare the malt 
extract for this purpose by digesting 5 grams of ground malt with 50 cc. 
of water for one and one-half hours at 20° to 30° C. In making the 
starch estimation, they digest for two hours at a temperature of from 
40° to 50° C. 20 grams of the sausage mixed with 20 cc. of the malt 
extract, and afterwards for eighteen hours at room temperature. After 
filtering and washing, the filtrate is boiled to coagulate the albumin and 
again filtered. The second filtrate is then made up to 200 cc, 20 cc. of 
25% hydrochloric acid (specific gravity 1.125) are added, and the starch 
determined in the regular manner. 

Mayrhojer's Melhod.-\ — This is considered the simplest and most 

* Berichte d. chera. Gesell., XII, p. 1285. 

t Zeits. Nahr. Untersuch., 1S96, p. 331; Abs. .■\nalyst, iSgy, p. 11. 



i86 



FOOD INSPECTION AND ANALYSIS. 



reliable method of estimating the starch in such substances as sausages. 
From 60 to 80 grams of the sample are heated on the water-bath with 
an 8% solution of alcoholic potassium hydroxide, which, in the case of 
pure sausages, dissolves nearly everything except a little cellulose. To 
prevent gelatinization, warm alcohol is added to dilute the solution, 
which is then iiltered through paper or asbestos. The starch is con- 
tained in the insoluble residue, which is washed with alcohol till the wash- 
ings are no longer alkaline, after which it is treated with an aqueous solu- 
tion of potassium hydroxide, and the starch solution made up to a definite 
volume. To an aliquot part of the solution 95% alcohol is added, where- 
upon the starch comes down as a flocculent precipitate. This is col- 
lected on a weighed filter, washed with alcohol and ether, dried, and 
weighed. The filter with its contents is then burnt to an ash, the amount 
• of which is deducted. 

In order to avoid the ash determination, the starch may be precipitated 
from a weak acetic acid solution instead of from an alkaline solution, the 
potassium acetate formed being soluble in the alcohol, and nothing but 
pure starch is precipitated. 

Characteristics of Horse Flesh. — Although certain authorities have 
found distinguishing characteristics in color, consistency, odor, etc., between 
horse flesh on the one hand, and beef and pork on the other, it is extremely 
diflicult, by its physical properties, to detect horse flesh when mi.xed with 
other meat, especially when the mixture is chopped. Horse flesh has a 
much coarser texture and is darker in color than beef. The muscle fibers 
are, as a rule, shorter in horse flesh. On treating horse flesh with formal- 
dehyde, Ehrlich * has found that a very characteristic odor is developed 
within forty-eight hours, suggestive of roasted goose flesh. 

Certain of the constants of the fat of horse meat differ from those of 
beef and pork, notably the iodine value and the rcfractometer readings. 
These constants are compared as follows : 





Iodine Value. 


Butyro-refractom- 

eter Readings. 
Temperature 40°. 


Horse fat 


71-86 
38-46 
5c^70 


53-7 
49-0 
48 - 6-5 1 . 2 


Beef fat 


Hog fat 



The fact that glycogen usually exists to a much larger extent in horse 
* Zeit. Fleisch u. Milch Hyg., 1895, p. 232. 



FLESH FOODS. 



187 



flesh than in other meat, renders it possible in some cases to detect horse 
flesh, when present in the mixture. 

The following table prepared by Bujard shows the relati\e amount 
of glycogen in various kinds of meat and sausages : 





Water. 


Glycogen Direct. 


Glycogen in Dried 
Substance. 




Niebel 
Method. 


Mayrhofer 
Method. 


Niebel. 


Mayrhofer. 




74-44 

74-87 

76.17 

76.00 

69.26 

67.25 

74-6 

75-° 


0.440 
0.600 
1.827 
0.592 


0-445 

0.520 

1.727 

0.610 

0.038 

0.24 

0.086 

0.186 


I-721 
2.388 
7.667 
2-466 


1. 741 
2.069 
7.247 
2.542 
0. 124 


it 


,1 


tt 


Red sausage (iLnackwurst) 




0-733 
0-342 
0-744 


Veal. 


Pork 





In beef Bujard found 0.74 and 0.073 P^^ cent of glycogen calculated in 
terms of dried substance, and, in sausages made exclusively from horse 
meat, amounts of glycogen ranging from 0.05 to 5.34, the sample in the 
latter case being made from the liver. It was formerly thought possible 
to detect as small an amount as 5% of horse flesh in mixture, but later 
investigation showed that after the death of the animal, glycogen, though 
present at first in considerable quantity, decomposes more or less rapidly, 
going over into muscle sugar (dextrose). Hence, while the presence of 
much glycogen is suspicious, its absence is by no means proof that horse 
flesh was not used. 

Niebel did not consider the failure of the glycogen test as sufficiently 
conclusive to estabhsh the absence of horse flesh, on account of the tendency 
toward decomposition of the glycogen. In the absence of starch, he 
regards the presence of more than 1% of dextrose in the fat-free meat, 
after conversion of the carbohydrates, to be proof of the presence of horse- 
flesh. 

Detection of Glycogen. — From the well-known color reaction produced 
by iodine on glycogen, horse flesh can often be detected, when present in 
sausages, unless obscured by the presence of starch or de.xtrin. 

Brautigam and Edelmann* proceed as follows: 50 grams of the finely 
divided meat are boiled with 200 cc. of water for an hour, and, after cool- 
ing, dilute nitric acid is added to the broth to precipitate the proteids 
and to decolorize. The broth is then filtered, and a portion of the filtrate 

* Pharm. Central., 1893, p. 557. 



1 88 FOOD INSPECTION AND ANALYSIS. 

is treated in a test-tube with a freshly prepared, saturated, aqueous solution 
of iodine, or, better, with a mixture of 2 parts iodine to 4 parts potassium 
iodide and 100 parts water, the reagent being carefully added so as not 
to mix with the broth, but form a layer above it. If glycogen be present 
in considerable amount, a wine-colored ring is observable at the junction 
of the two layers. On heating the test-tube, the coloration disappears 
if due to glycogen, but it reappears on cooling. This reaction was found 
to occur with horse flesh and not with beef, mutton, veal, or pork.* 

If the color is not clearly apparent, the chopped meat is heated on the 
water-bath with a solution of potassium hydroxide (using an amount of 
potassium hydroxide equivalent to 3% of the weight of the flesh) till the 
fiber is decomposed, after which the broth is concentrated to half its volume, 
treated with nitric acid to precipitate the proteids, filtered, and treated 
with the iodine solution as previously. 

Determination of Glycogen.f — NiebcPs Modification of Briicke's 
Method. — This method is applicable only in the absence of dextrose and 
dextrin. If therefore the presence and character of the starch indicates 
the presence to a considerable extent of cracker crumbs or other cereal 
"filler," the method is not accurate. 

A weighed portion of the flesh is heated on the water-bath with 3 to 4 
per cent of potassium hydroxide and four volumes of water for six hours. 
Evaporate the broth to half its original bulk, and add, after cooling, a 
solution of mercuric iodide in potassium iodide ,t which precipitates the 
protein. Filter, and to the clear filtrate add 2h times its volume of 95% 
alcohol, collect the precipitated glycogen on a filter, wash first with 60% 
alcohol, then with 95% alcohol, then with absolute alcohol, then with 
ether, and finally with absolute alcohol. Dry at 115° C. and weigh. 

Landwehr^s Method. — Applicable in presence of dextrose. The broth 
prepared as in Niebel's method is freed from protein by the addition 
of zinc acetate. FiUer, wash, and heat the entire fiUrate on the water- 
bath with sufficient of a concentrated solution of ferric chloride, after- 
wards precipitating the iron with a few drops of a saturated solution of 
sodium hydroxide. Filter, wash the precipitate with hot water, and dis- 

* The reaction was found to occur also with the flesh of the human foetus and with the 
fcEtus of animals; also with mule meat, but not with the flesh of the dog or cat. 

t Jahresb. Nahr. Genuss., i8gi, p. 38. 

X The reagent known as Briicke's reagent is prepared by precipitating a solution of mer- 
curic chloride with potassium iodide, washing the precipitated mercuric iodide till free from 
chloride, and afterwards saturating, while boiling, a 10% potassium iodide solution with the 
mercuric iodide. 



hLESH FOODS. 1 89 

solve in strong acetic acid. Add to the solution, after cooling, sufficient 
hydrochloric acid to produce a yellow color, then pour into 2^ volumes 
of alcohol, and proceed as in the preceding paragraph. 

Mayrhojer's Method,* on which the results in the table on page 187 
are based, is as follows: Dissolve a weighed portion of the flesh in an 
aqueous solution of potassium hydroxide, precipitate the proteids by 
hydrochloric acid and Nessler's reagent, filter, and treat the clear filtrate 
with alcohol, which precipitates the glycogen. This is collected on a 
tared filter and washed, first with dilute alcohol, and finally with ether, 
dried at iio°C., and weighed. 

Pfliigcr and Nerking's Method.^ — Of the finely divided sample 50 grams 
are heated on the water-bath with 200 cc. of 2% potassium hydro.xide 
till the solution is practically complete. After cooling, the solution is 
made up to 200 cc. with water, shaken, and filtered. To 100 cc. of the 
filtrate, 10 grams of potassium iodide and i gram potassium hydro.xide 
are added, and the solution stirrred till clear, after which 50 cc. of 95^ 
alcohol are added and the mixture allowed to stand over night. This 
precipitates the glycogen. Filter, and wash the precipitate with a solution 
made up of i cc. 70% potassium hydroxide, 10 grams potassium iodide, 
100 cc. water, and 50 cc. 95% alcohol. After further washing the glycogen 
with 2 parts strong alcohol and i part water, dissolve in water and by 
means of Briicke's mercuric-iodide-in-potassium-iodide reagent (see foot- 
note, p. 188) remove any remaining nitrogenous substances. Filter if 
turbid, and to the solution add common salt (about 2 milligrams per 100 cc. 
of solution), and reprecipitate the glycogen by adding 2 volumes of 95% 
alcohol. Filter, wash first with 95% alcohol containing a little common 
salt, then with absolute alcohol, and lastly with ether. Dry and weigh. 

Bigelow suggests that the glycogen as above obtained be converted 
by acid hydrolysis to dextrose, which is determined in the regular manner. 
Dextrose X .9 = glycogen. 

Identification of Raw Horse Flesh by the Blood Serum Test.J — This 
test depends upon the recent development of the principle that when a 
rabbit has been inoculated with the blood of a particular animal, as for 
instance that of the horse, the serum of the rabbit's blood will react with 

* Forsch. Ber., 1897, IV, 47. 

f Arch. gcs. Physiol., 1899, 76, 531-542; Bui. 65, Bur. of Chem., p. 13. Recommended 
for Provis. Adoption by the A. O. A. C. 

X Schiitze, A., Ueber wcitere Anwendungen der Pracipitine. (Deuts. med. Wochs., 
1902, No. 45, p. 804.) 

II assermann, A., u. SdiUlz-:, A., Ueber die Entvvickelung der biologischen Methode 



I go FOOD INSPECTION AND ANALYSIS. 

the blood of the horse and with that of no other animal. To prepare the 
blood serum for a reagent, inject a rabbit with lo cc. of defibrinated 
horse's blood ever)- day for five to six days, either subcutaneously or 
intravenously. The blood afterwards taken from the rabbit is clotted, 
and the filtered serum is used in making the test, or, if the reagent is to 
be kept for some time, the rabbit's blood serum is dried and an aqueous 
solution used for the reagent. 

If the clear expressed juice from the suspected flesh, filtered if necessar}', 
be treated with a few drops of the rabbit's blood reagent, prepared as 
above, a cloudy precipitate will be produced in the case of horse flesh. 

By inoculating different rabbits in like manner with the blood of 
various animals, the flesh of the corresponding animals may be recognized 
from the reaction of the blood serum of the rabbit with its juices. Only 
raw flesh responds to the test, as heating destroys the virtue of the reagent. 

Determination of Muscle Sugar {Dextrose). — Boil a weighed quantity 
of the finely divided sample, say 50 grams, with water, add an excess of 
normal lead acetate solution, and make up with water to a given volume, 
say 250 cc. Filter, and to an aliquot part of the filtrate add enough of 
a saturated solution of sodium sulphate to precipitate the lead. Again 
filter, make up to a given volume, and determine the dextrose in a measured 
part of the solution by either of the regular methods. 

Detection of Coloring Matter.— i?f(f Ocher is indicated by an excessive 
amount of iron in the ash. 

Cochineal is most readily tested for by the method of Klinger and 
Bujard.* The sausage, finely divided, is heated with two volumes of a 
mixture of equal parts of glycerin and water for several hours on the 
water-bath, the mixture being slightly acidified. The yellow solution 
is passed through a wet filter, and the coloring matter, if present, is pre- 
cipitated as a lake by adding alum and ammonia, the precipitate is filtered 
off and washed, after which it is dissolved in a small amount of tartaric 
acid, and the concentrated solution, contained in a test-tube, is examined 

zur Unterscheidung von menschlichem und tierischem Eiweissmittels Pracipitine. (Ibid., 

1902, No. 27, p. 483.) 

Wassermann, A., Ueber Agglutinine und Pracipitine. (Zeits. f. Hyg., etc., Bd. 42, 

1903, 2, p. 267.) 

Uklenhuth, Die Unterscheidung des Fleisches verschiedener Tiere rait Hilfe spezifische 
Sera und die praktische Anwendung der Methode in der Fleischbeschau. (Deuts. ATed. 
Wochs., 1901, No. 45, p. 780.) 

Miessner, H., 11. Herbsl, Die Serum agglutination und ihre Bedeutung fur die Fleis h- 
unteriuchung. (Arch. f. wissensch. u. prakt. Tierheilk., 1902, Heft 3-4, p. 359-} 

* Zeit. angew. Chem., 1891, p. 515. 



FLESH FOODS. 191 

through the spectroscope for the characteristic absorption-bands of carmine 
lake, lying between h and D. 

Spaeth * has shown that both carmine (cochineal) and anilin red, 
which are the dyes most commonly used for coloring sausages, can be 
most readily extracted therefrom by warming the finely divided material 
a short time on the water-bath with a 5% solution of sodium salicylate. 

Vegetable and Coal-tar Colors. — Various solvents are suggested for 
the removal of these dyes from sausage meat. Allen f recommends 
extraction with methylated spirit (a mixture of ethyl alcohol with 10% 
methyl); Bigelow X recommends heating with a mixture of 50% glycerin 
slightly acidified; A. S. Mitchell uses alcohol acidified with hydrochloric 
acid; Spaeth a 5% solution of salicylate of soda. Other solvents appli- 
cable in some cases are dilute ammonia and amyl alcohol. The solvent, 
after filtering, is evaporated to small volume, acidified with hydrochloric 
acid, and white wool is boiled in it. If the wool is distinctly dyed, a coal-tar 
color is undoubtedly present, and this can often be identified by methods 
given in Chapter XVI. According to Marpmann, pure normal flesh con- 
taining natural color only is completely decolorized by macerating for 
two hours in 50% alcohol, while artificially colored meat remains colored 
after this treatment. 

Marpmatm's Microscopical Method.^ — Moisten a thin section of the 
sausage with 50% alcohol, and examine under the microscope. Some 
colors are readily apparent without further treatment. If only traces 
of color are present, clarify the substance by treatment with .xylol, which 
is removed by the use of carbon tetrachloride. The mass rendered 
transparent by this treatment is then immersed in cedar oil and examined, 
the coloring matters, if present, being especially apparent. If the color 
used is fuchsin (magenta), carmine, logwood, or orchil, the substance 
of the cell will appear stained. If acid coal-tar dyes are used, the liquid 
contents of the cell will show the color. 

Detection of Frozen Meat. — Maljean || detects frozen meat by the 
aid of a microscope. A drop of the blood or meat juice is pressed out 
upon a slide and immediately examined before it solidifies. Fresh meat 
juice contains many red blood corpuscles, floating in a clear colorless 
serum, and readily apparent. In blood from frozen meat, the red cor- 

* Pharm. Central., 1897, 38, p. S84. 

t Commercial Organic Analysis, Vol. IV, p. 294. 

J U. S. Dept. of Agric, Bureau of Chemistrj', Bui. 65, p. 16. 

§ Zeits. angewand. Mikrosk, 189s, p. 12. 

II Jour. Pharm. et Chem., 1892, XXV, p. 348. 



192 FOOD INSPECTION /IND /IN/1 LYSIS. 

puscles are nearly always completely dissolved in the serum, due to freez- 
ing, or, if riot dissolved, are much distorted and entirely decolorized, the 
liquid portion being darker than usual. 

Megascopically, the fresh meat juice is more abundant than that of 
frozen meat, and its color is deeper. According to C. A. Mitchell, if a 
small piece of meat once frozen be shaken in a test-tube with water, color 
is imparted to the water much more quickly than with fresh meat, and 
the color is deeper. 

MEAT EXTRACTS. 

Character and Composition. — Numerous preparations sold under the 
name of meat extracts have been on the market for many years. At the 
beginning of the nineteenth century the value of such extracts was known, 
but Liebig was the first some fifty years later to produce a commercial 
extract of meat. Liebig's preparation, as originally made, consisted 
of a cold-water extract of chopped lean meat, strained free from fiber, 
heated, filtered, and evaporated, thus containing little of any gelatin or pro- 
teids. Later, however, Liebig advocated the use of warm and even boiling 
water for extraction, by which method of preparation the amount of 
gelatin was greatly increased. He, however, condemned the use of salt. 

The best modern meat extracts consist for the most part of such por- 
tions of the meat, previously freed from bone and superfluous fat, as 
are soluble in water the temperature of which does not exceed 75° C. 
The widest latitude, however, prevails as to the temperature employed 
for the extraction, hence the character of the various products is some- 
what varied. It is not an uncommon practice to submit the meat to 
actual boiling with water, in which case the amount of gelatin will be 
considerable. In an extract prepared by warm water, one finds very 
Httle gelatin, more or less albumin, albumose, and peptones, and prac- 
tically all the flesh bases, phosphates, and chlorides present in the meat; 
also minute quantities of lactic acid, inosite, and possibly glycogen. By 
far the most important of these substances from the physiological stand- 
point are the flesh bases — creatin, creatinin, xanthin, sarkin, etc. To 
the predominance of these amido-bodies is undoubtedly due the well- 
known stimulating effect of meat extracts. Indeed, a properly prepared 
extract has very little actual food value, but is rather to be regarded as 
a condiment or as a stimulant, acting on the nervous system in a some- 
what analogous manner to tea and coffee. 

Commercial meat extracts differ much in consistency according to 



FLESH FOODS. 



»93 



the extent to which evaporation is carried, varying from the thin fluid 
through the pasty form to the semi-soHd. Some preparations have added 
thereto finely ground dried beef or beef meal. 

The following table shows results obtained by Otto Hehner on some 
of the principal commercial meat extracts: 













c 








s 


OJ CJ 

m 


J3 



15.26 


0.34 


5-i8 


15-97 


0.21 


3-31 


I7-S5 


0.38 


4.5b 


22.24 


0.29 


5-5° 


.s.';-4« 


0. 10 


0.69 


55-53 


O.IO 


0-7S 


61.61 


0.08 


1. 12 


36.19 


0.25 


1-37 


70.19 


0.32 


0.45 


89.69 


0.06 


5- 18 


28.34 


1.02 


3-81 



ii.oJ:.S 



1 . Liebig Company's Exiractiim Carnis 

2. Armour's extract of meat 

3. Brand & Co.'s Exiractum Carnis. . . 

4. Liebig's extract (Bovril Co.) 

5. Brand & Co.'s meat juice 

6. Valentine's meat juice 

7. Wyeth's meat juice 

8. Borthwick's bouillon 

g. Vitalia meat juice 

10. Brand & Co.'s essence of beef 

11. Bovril Co.'s beef fluid 



1. 00 
0.25 
5.62 



16.44 



1. 81 
1.30 



4.00 
0-37 



5-37 



2.01 

1-75 
4.19 
3.62 
1.06 
2.00 
1.08 
1. 16 
0.05 
0.19 
8.38 



8.06 

5-13 
10.16 

8.44 
2.50 
2.87 
1.86 

11.09 
0-37 
0-57 

13.18 







6 




J, 




g 


£■■? 


-Si 






3^ 


S " 




8: 




s" 


< 


Q 


&^ 


39-32 


23-51 


4.20 


5.81 


41.12 


29.36 


3-15 


9-74 


38.90 


18.80 


2.87 


3-31 


38-59 


20.45 


—0.42 


5-14 


12.50 


11.06 


15.61* 


4-43 


12.48 


12.01 


14.01 


2-35 


9-44 


14.78 


4.41 


6.96 


24-25 


17-93 


3-76 


6.09 


2.82 


6.65 


2.34 


5-II 


3-43 


1. 00 


— 0.05 


0-33 


19.38 


17.67 


2.85 


9.07 








Im. 






a 


X. 




^TJ 


^,^ 










^< 


p'^ 




H 



1. Liebig Company's Exiraclum Carnis 

2. Armour'sextract of meat 

3. Brand & Co.'s Exiractum Carnis 

4. Liebig's extract (Bovril Co.) 

5. Brand & Co.'s meat juice 

6. Valentine's meat juice 

7. Wyeth's meat juice 

8. Borthwick's bouillon 

9. Vitalia meat juice 

10 Brand & Co.'s essence of beef 

1 1 . Bovril Co.'s beef fluid 



6-97 
6.76 
5-16 
5-5° 
1-52 
2.85 

3-01 
3-58 
0-37 
0.40 

4-05 



9.07 
8.21 
.80 



9 

9 

2 

2 

3 

6-7^ 

3.28 

1.49 

8.02 



19 
81 
92 
06 



♦Glycerine). 

In calculating the percentage of the various nitrogenous compounds, 
the factor 6.25 was used in all cases, this being in Hehner's opinion the 
fairest and best approximation to the true state of affairs in expressing 
the analysis as a whole, while admitting that this factor is too high in 
certain cases, as, for instance, in that of the flesh bases. 

McGill t gives the following results of the analysis of twenty-three 
brands of meat extracts: 



t Dept. of Inl. Rev. Canada, Bui. 63, p. 36. 



194 



FOOD INSPECTION ^ND /tN/i LYSIS. 



< 

H 
u 

CJ 

w 

PL, 



o 



O 

o 



h 
2 
O 
u 

u 

M 
H 
l« 

Ol 

Z 

O 
u 

>^ 

H 

< 

o 

h 
u 
< 

><! 
W 

h 

<: 
w 
S 



o 



Equiv- 
alent 
Flesh 

Basea 

NX 8. 12. 


00 O CN ■* u-i r^ rrjoo CO 


Nitrogen 
in Soluble 

Matter 
not Ppt'd 

Bromine. 


O c^co lo o fr) •-■ oco 

^ \J~, e<i \n rJ-OCOr^CN 


Equiv- 
alent 
Proteids 
NX 6.25. 


Q> o •-* r^ O (N LoO 
CX3 M CO ro O CO M LO 
<N c>00 ■* SO lO ►H Tt -^ 

»-t M M Ht 


Nitrogen 
in Soluble 

Matter 
Ppt'd by 
Bromine. 


00 ij^ o c^ « o o^co *^ 
or-'-'c* sooco'O'-' 

^ O O CO OO t-^CO LT) 
dOrOM M«i-«0'-' 


Equiv- 
alent 
Proteids. 
NX6.25. 


i/^ iH O O *-• •& -rt Tj-cO 


Nitrogen 

in 

Portiun 

Insoluble 

in Water. 


r- LTi »-> r^ oco w ■+ ro 

d d d d d d d d d 


^ Hi 

M 


O O O r^Mir^^r^O O 
ro O "O ^.00 <r) HH TfOO r^ 


Fat, Pe- 
troleum- 
ether 
Extract. 


t^ rn t~^ O^ u~. f^ rJ-t-..CN ('T, 
>-• r~* U-, r-» U-, i-r f^ o ^1 

-i'-^dddddd'-^d 


Chlorine. 
Calcu- 
lated to 
NaCi. 


O'^iOMO'-'-l-r^OO 
r--CO00 O •1--fON I-- 

CO i^O OO O --I O f^ - 

M « M c^ 


< 


« a- o o '^ -+ f^o o o 
w t— -^o --QO TJtN t^ fn 




O Ol r- ir^ « CO u-i OOO c^ 

M t^cO "O o oco o o >o 


No. of 
Sam- 
ples 
Ana- 
lyzed. 


rcc< poccmpi <n w co<n 




y 

c 
£ 
< 


> 

c 

c 


3- Johnston's 

4. Libby, McNeil & Libbv's. 

5. Liebig's— Ont. Mfg. Co.. . 

6. Liebig's — Ext't Co., Chic. 


a, 
rt 

s 


a. 

- c 
E 

c 


r 
^ 





O t^ f^ r-^ O t^ 
t^oo CO r.->o tn 
t^oo ir->oo 00 'I- 



< 



W 



P^ 
O 

o 



'J- O 00 ^ r- oco o 
^ c* ^00 CO r» f^ fo 



\00 00 Tt- U-) M o 

<MO OOOfNCOO 

00 00 O N r^oo U-) 



HH 







•rl- N LO 10 


10 


■^ r^iOO Lo CD 



n 



M 



to 



as 
I § 



o rt C , 

._^|l3.2P.S 



1- N (-Q Tj- Lr,\0 rC.oo o 



Pi 





-1- 




tr-, 




rOsO 


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* < 




rf 




t^ 






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? ai 






■* 




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100 ^ 



t^ 









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i-J 






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Lh 
























ri 





(N 


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(N 


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r*. 


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wcc 




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M 


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(^ 


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r^ X 


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w 




















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w 





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w 


fn rn Tf- 00 -o 


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■"i- 


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r 


< 


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Ph 




















t3 




<N 


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N 


<N 


N 


w 


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ro 




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^ 10 o 
O O 00 



« 10 O c 
rOOO O O 



d2 



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^O O N 00 
IH 4^ "i-OO 



Tt ooc o 
o t--o -^ 

CN O 00 CM 




o o o <^ 
2 Z ^ « 



O H* 10 o 

O CO c^ ^ 

^> o ■^oo 

« O >-< C'O 



00^0 



« eS CN N 



.5 Ji « ^ 

.« O c w 
> C rt u 
O rt I- o 

PQ pupa pa 
c5 -^ ^* fo 



FLESH FOODS. 195 

METHODS OF ANALYSIS. 

Water. — According to Stutzcr * water is best estimated by weighing 
from 5 to 7 grams of the preparation (if of the dry or pasty variety), or 
from 20 to 25 grams of the fluid extract into a large platinum dish, the 
dry variety being dissolved in a little hot water. A sufficient amount 
of previously ignited asbestos or sand, sifted free from dust, is added 
to absorb the liquid, and the whole is dried to a constant weight in the 
air-oven. 

Ash. — The residue from the above is carefully incinerated in the 
original dish and weighed. Ammonium nitrate may be employed in 
burning, if necessar>'. The chlorine is determined volumetrically or 
gravimetrically in a solution of the ash. 

Fat. — This is best obtained by extracting a portion of the air-dried 
substance with petroleum ether in a Soxhlet apparatus. Petroleum 
ether extracts the fat only, while ether extracts other substances as well. 
K properly prepared extract has very little fat. 

Total Nitrogen. — The extract should be tested for nitrates, and the 
proper modification of the Gunning method should be employed, depend- 
ing on the presence or absence of nitrates. Use from i to 5 grams for the 
determination. 

Separation of Nitrogenous Compounds. — To correctly gauge the food 
value of a meat extract, it is essential to separate and estimate at least 
roughly its principal nitrogenous components. To attempt to make such 
a separation with a high degree of accuracy would involve a long and 
tedious series of operations, which in most cases would be impracticable. 
Usually the separation into three main groups, as outlined on page 181, is 
sufficient. At times, however, it may become necessary, or at least desir- 
able for specific purposes, to determine certain of the nitrogenous com- 
pounds separately. Various approximate quick methods are in use for 
this purpose, and by reason of the fact that in all these methods each 
class of nitrogenous substances that should theoretically be separated 
under given conditions is contaminated to some extent with members of 
other classes, or is itself incompletely separated, it is best to specify in all 
cases the particular method employed. The most common process 
among the manufacturing chemists is to employ alcohol of varying strength 
for fractional precipitation. 

Briiylanls f adds sufficient alcohol to the solution to amount to 40% 

* Zeits. anal. Chemie, 1895, p. 368. 

t Jour. Pharm. et Chem., 1897, V, p. 515. 



196 FOOD INSPECTION AND ANALYSIS. 

strength. This precipitates mainly the gelatin. The concentrated filtrate 
from this precipitation is next treated with alcohol to the strength of 80%, 
which separates out the albumose. Finally the peptones are removed by 
alcohol of 93 to 94 per cent strength, the flesh bases remaining in solution. 
Nitrogen is determined separately in each portion. 

Hehner * roughly separated the gelatinous and proteid substances from 
the flesh bases by the use of methylated spirit (a mi.xture of ethyl alcohol 
with 10% of methyl alcohol). He dissolved about 2 grams of the sample 
in 25 cc. of water, added 50 cc. of strong, methylated spirit, and allowed 
the mi.xture to stand over night. He then decanted off the clear super- 
natant liquid, and dissolved the precipitate in hot water without washing, 
after which he evaporated the solution to dryness in a tared dish at 100° C. 
and weighed. 

Wiley's Classification t for practical purposes is onvenient and very 
satisfacton,'. It was used by McGill in obtaining the results given on page 
194. 

The total nitrogen is divided into three groups as follows : 

1st. Nitrogen in the insoluble proteids. 

2d. Nitrogen in the soluble proteids, as precipitated with bromine 
in acid solution. 

3d. Amido-nitrogen (including the flesh bases) in the filtrate from 
the bromine precipitation. 

(i) Insoluble Nitrogen. — A weighed amount of the sample is treated 
with a large excess of warm water, the insoluble residue separated by 
filtration, dried, and weighed. The whole or an aliquot part of this residue 
i then used for determination of nitrogen by the Gunning method. 
N X 6. 2 5 = insoluble protein. 

(2) Soluble Proteid Nitrogen. — The filtrate from the above precipita- 
tion is received into a Kjeldahl flask and acidified with a few drops of 
dilute hydrochloric acid, after which it is treated with an excess of liquid 
bromine, with which it is shaken and allowed to stand over night. It is 
then filtered, and the precipitate washed with bromine water in the manner 
described on page 182. The nitrogen in the precipitate is then deter- 
mined by the Gunning method. Nx6.25=soluble proteids. 

(3) Amido-nitrogen. — Flesh Bases. — This is most conveniently ob- 
tained by difference, deducting from the total nitrogen the sum of the 
insoluble and the soluble proteid mtrogen (i) and (2). NX3.i2 = flesh 
bases. 

♦Analyst, X, p. 221. t U. S. Dept. of Agric, Bureau of Chemistn-, Bui. 54. 



FLESH FOODS. 197 

Complete Separation of Nitrogen Compounds would involve a discrimi- 
nation between meat fiber and insoluljle protein, coagulable albumin, 
acid albumin (syntonin), gelatin, peptones, albumoses, flesh bases, and 
ammonia. 

(i) Meal Fiber. — If meat fiber is found by examination with the micro- 
scope to be present, about 5 grams of the extract of the dry, or 20 to 25 
grams of the fluid variety is exhausted with 200 to 250 cc. water at about 
20° C, and the residue collected on a tared filter. It is often difficult to 
filter such an extract in the ordinary way, and the use of the centrifuge 
is helpful, passing the clear supernatant liquid through the filter, and 
finally washing the residue thereon. The residue is washed, dried at 100°, 
and weighed, or the nitrogen may be determined by the Gunning method. 
NX 6.25= total insoluble matter, which includes, besides the meat fiber, 
the insoluble proteids. 

(2) Coagulable Albumin. — The filtrate from (i) is ac'dified with acetic 
acid and boiled for some minutes to coagulate the albumin, which is col- 
lected upon a filter (using to advantage a centrifuge as in the preceding 
paragraph). Determine the nitrogen in the washed residue, using the 
factor 6.25 for coagulable albumin. 

(3) Acid Albumin or Syntonin. — Exactly neutralize the filtrate from 
(2) with weak alkali. If a precipitate occurs, indicating syntonin, it is 
collected on a filter, washed, and the nitrogen determined. N X 6. 25 = syn- 
tonin. 

(4) Albumoses or Proteoses. — An aliquot part of the filtrate from (3), 
or if syntonin be found absent, of the filtrate from (2), is saturated with 
zinc sulphate, adding the powdered salt as long as it continues to dissolve 
with stirring and shaking. Proteoses and any traces of gelatin or insoluble 
proteids that have escaped removal are precipitated, but not the peptones 
or flesh bases. Filter, wash, and determine the nitrogen in the residue, using 
the factor 6.25 for the proteoses. 

(5) Peptones. — The filtrate from (4) or an aliquot part thereof is 
acidified with hydrochloric acid and treated with bromine in the manner 
described on page 182. The residue is collected and washed. The 
nitrogen therein X 6. 25= peptones. 

(6) Flesh Bases are determined by subtracting from the total nitrogen 
the sum of the nitrogen in (i), (2), (3), (4), and (5), and multiplying the 
remainder by the factor 3.12. 

Two samples of commercial meat extract were analyzed by A. McGill 
by methods closely analogous to the above, with the following results: 



198 



FOOD INSPECTION AND ANALYSIS. 



Insoluble residue 

Total nitrogen 

Equivalent protein (NX 6. 25) 

Soluble matter 

Nitrogen in coagulable albumins 

Coagulable albumin (NX6.25) . . . . 

Syntonin (acid albumin) 

Proteose nitrogen (by zinc sulphate) 
Equivalent proteoses (NX6-25)- ■ - • 

Peptone nitrogen 

Equivalent peptones (NX6.25) . ... 
Amido-nitrogen (flesh bases) by dif. . 
Equivalent flesh bases (NX3.12). . . 



Vigoral. 



8-95 
1.047 

6-544 
47-45 
0.0196 
0.1225 
None 
0-314 
1.963 

1-059 
6.621 

2-305 
7.192 



Vimbos, 



6.32 
0.906 
5.663 
50.18 
0-058 

0-363 
None 
0.391 
2.444 
1.400 

8-750 
2.447 

7-635 



Determination 0} Gelatin. — This is accomplished by the modified 
Stutzer method as given on page 183. 

Determination oj Ammoniacal Nitrogen. — This is best estimated, ac- 
cording to Stutzer, by dissolving 5 to 25 grams of the preparation in 
water (if the extract is not of the fluid variety), adding barium carbonate, 
and distilling into a standardized acid. Nitrogen in the form of ammonia 
salts is rarely present in these preparations. 

Preservatives in Meat Extracts. — Boric acid is sometimes used 
as a preservative in these preparations and is tested for by the usual 
methods (p. 185). 

FISH. 

Structure and Composition. — Fish resembles meat both structurally 
and in the nature of its constituents, but differs from it in a marlced degree 
in the relative proportions of its various components. Thus, there is 
considerably more refuse matter such as skin and bones in fish than in 
meat, and in the edible portion of fish the amount of water is much greater. 
Comparing the nitrogenous components of each, we find in fish more 
of the gelatin-yielding matter (collagen) and less of the extractives than 
in meat. There is much less haemoglobin or allied coloring substance 
in the flesh and blood of fish than in meat, which accounts for the white color 
usually characteristic of the former. Certain fish, however, hke the salmon, 
probably owe their distinctive color to a pigment belonging to the lipo- 
chrome* class. The mineral content of fish, as a rule, exceeds that of 
meat and contains more phosphates. The various edible fishes differ 
less among themselves in composition than do the meats. According to 
Chapman the average composition of fish is as follows, in parts per 1000. 

* a series of fatty animal pigments. 



FLESH FOODS. 



199 



Water 740.82 

Albumin 137-40 

Collagen 43-88 

Fat 45.97 

Extractives 16.97 

Salts 14.96 

Hutchison classifies fish as follows with reference to their content of fat : 

Lean. — Fish having less than 2% fat, such as cod and haddock. 

Medium. — Fish having 2 to 5% fat, such as halibut and mackerel. 

Fat. — Fish having more than 5% of fat, such as eel, 18%; salmon, 12%; 
turbot, 12%, and herring, 8%. 

According to Atwater and Bryant * the composition of different varie- 
ties of fish is as follows: 

COMPOSITION OF FISH. 



Refuse 



Water. 


Protein. 


Fat. 


Ash. 








NX 


By 








6.25. 


Differ- 
ence. 






77-7 


18.6 


18.3 


2.8 


1.2 


3S-I 


8.4 


8-3 


I.I 


°-5 


7«-S 


19.4 


19.0 


1.2 


1-3 


40-3 


10. 


q.8 


0.6 


0.7 


82.6 


16., 


1^.8 


0.4 


1 .2 


38.7 


8.4 


8.0 


0.2 


0.6 


71.6 


18.6 


18., 


9-1 


1.0 


S7-2 


14.8 


14.6 


7-2 


0.8 


81.7 


17.2 


16.8 


0-3 


1.2 


40.0 


8.4 


8.2 


0.2 


0.6 


75-4 


18.6 


18.4 


5-2 


1.0 


61.9 


15-3 


15-1 


4-4 


0.9 


72-S 


19-5 


18.9 


7-1 


1-5 


41-7 


II. 2 


10.9 


3-9 


0.9 


73-4 


18.7 


18.3 


7-1 


1 .2 


40-4 


10.2 


10. 


4.2 


0.7 


75-7 


19-3 


19. 1 


4.0 


1.2 


28.4 


7-3 


7-2 


1-5 


0.4 


79-8 


18.7 


18.6 


o-S 


I.I 


42.2 


9-9 


10.7 


0-3 


0.6 


64.6 


22.0 


21.2 


12.8 


1-4 


40.9 


15-3 


14.4 


8.9 


0.9 


70.6 


18.8 


18.6 


9-5 


1-3 


35-2 


9-4 


9.2 


4-8 


°-7 


82.2 


18.2 


15-3 


1.6 


I.I 


40.2 


8-9 


7-5 


0.7 


0.6 


79-2 


17.0 


17-3 


1. 8 


1-7 


46.1 


10. 1 


10. 


I.O 


1.0 


77.8 


ig.2 


18.9 


2.1 


1.2 


40.4 


9.9 


9-8 


I.I 


0.6 


71.4 


14.8 


12.9 


14.4 


1-3 


37-3 


7-7 


6.8 


7-5 


0.7 


69.8 


22.9 


22.1 


&-5 


1.6 


32.5 


10.6 


10.3 


3-0 


0-7 



Fuel 
Value 

per 
Pound. 



55-0 
48.6" 



52-5 



51-0 



17-7 



Bass — edible portion 

as purchased 

Bluefish — edible portion 

as purchased 

Cod — edible portion 

as purchased , 

Eel — edible portion , 

as purchased , 

Haddock — edible portion , 

as purchased , 

Halibut — • edible portion 

as purchased 

Herring — edible portion 

as purchased I 42.6 

Mackerel — edible portion I 

as purchased I 44.7 

edible portion I 

as purchased I 62 . 5 

edible portion ' 

as purchased 47-1 

edible portion 

as purchased , 

edible portion 

as purchased 

edible portion 

as purchased 

edible portion , 

as purchased , 

edible portion , 

as purchased 

Turbot — edible portion 

as purchased 

Whitefish — edible portion , 

as purchased , 



Perch — 
Pickerel- 
Salmon— 
Shad- 



Skate— 



Smelt- 
Trout— 



34-9 



5°-i 



51-0 



41.9 
48.1 



47-7 



53-5 



465 
200 
410 
210 

325 
165 
730 
580 

335 
165 
565 
470 
660 
375 
645 
365 
530 
200 

370 
210 

95° 
660 
750 
380 
400 
195 
405 
230 

445 
230 
S85 
460 
700 
325 



* U. S. Dept. of Agric, Ofif. of Exp. Sta., Bui. 28, p. 47 et seq. 



zoo FOOD INSPECTION AND ANALYSIS. 

Crustaceans and Mollusks. — These differ from the meats and common 
fish by reason of the presence in considerable proportion of the carbohy- 
drate glycogen, contained in the liver. The lobster and crab are nearly 
ahke in composition, the flesh being made up of coarse, dense, thick-walled 
fibers. 

Payen gives the following composition of the flesh and body of lobster: 

Flesh (contained in Body (consisting 
Claws and Tail). mainly of Liver). 

Water 76.6 84.31 

Proteid i9-i7 12.14 

Fat 1. 1 7 1. 14 

Clams and Oysters are low in solid nutriment, and are more digestible 
when eaten raw than cooked. Oysters contain 3% or more of glycogen. 
The following analyses are from Atwater and Bryant:* 

COMPOSITION OF SHELL FISH, ETC. 



Refuse.' Water 



Pro- 
tein. 
NX 
6.25. 



Fat. 



Car- 
bohy- 
drates. 



Ash. 



Fuel 
Value 

per 
Pounil. 

Cals. 



Clams — 
Crabs — 
Lobster— 
Mussels- 
Oysters— 

Scallops— 
Terrapin- 
Turtle— 



edible portion. 

as purchased. . 

edible portion. 

as purchased. . 

edible portion. 

as purchased. . 
• edible portion. 

as purchased. . 

edible portion. 

as purchased. . 
■ as purchased . . 
-edible portion . 

as purchased . . 

edible portion. 

as purchased . . 



41.9 
52-4 



61.7 
46.7 



75-4 
76.0 



8.6 

5-° 
16.6 

7-9 
16.4 

5-9 
8-7 
4.6 
6.2 
1.2 
14.8 
21.2 

5-2 
19.8 

4-7 



i.o 
0.6 
2.0 
0.9 
1.8 
0.7 
i-i 
0.6 
1.2 



0.1 

3-5 
0.9 

0-5 
0.1 



2.0 
1. 1 
1.2 
0.6 
0.4 
0.2 
4.1 
2.2 

3-7 
0.7 

3-4 



2.6 

1-5 
3-1 
1-5 
2.2 
0.8 
1.9 
1.0 
2.0 
0.4 

1-4 
1.0 
0.2 
1.2 
0-3 



240 
140 
415 
195 
390 
140 

=85 
150 
235 

45 
345 
545 
135 
390 

90 



Characteristics of Fresh Fish. — Fish of all kinds should be eaten when 
perfectly fresh, as it undergoes decomposition much sooner than meat 
when killed. While with meat aging is often beneficial to bring out 
requisite tenderness and flavor, in the case of fish deterioration begins 
almost immediately after death. Even though certain varieties of fish 
may be kept firm and wholesome for some days on ice, the flavor is dis- 
tinctly impaired by long keeping. Fish that is not perfectly firm to the 
touch, or that has abnormally dry scales, or that shows blubber at the 
* U. S. Dept. of Agric, Off. of Exp. Sta., Bui. 28, pp. 52 and 53. 



FLESH FOODS. 



201 



gills, or that possesses the marked odor that accompanies incipient decom- 
position, should not be used as food. 

Methods of Analysis. — These are similar to the methods given for 
meat. 

Preservatives in Fish and Oysters. — Boric acid and borax in mixture 
form the most common preservatives of salt dried fish and of oysters. 
In the case of salt codfish, the boric mixture is sprinkled on the surface. 
Such surface application in some states, as for example Massachusetts, is 
allowed by law. In opened oysters sold in casks and kegs, the liberal 
use of boric mixture is frequent in solution in the oyster hquor. 

The author has found salicylic acid in bottled clam juice and clam 
bouillon. 

CONCENTRATED FOODS. 

Under the name of "condensed" or "concentrated foods" or "emer- 
gency rations" a number of canned preparations are sold for the use of 
campers, travelers, armies in the field, etc. These consist usually of 
mixtures of dried ground meats and vegetables, pressed together in com- 
pact form, and preserved in tin cans. The claims made for the food value 
of these preparations are, as a rule, extravagant and erroneous, as shown 
by Woods and Merrill,* who give the following analyses of some of these 
foods : 



Net 
Weight 
Con- 
tents. 



Weight of Materials in Package. 



Water. 



Prn- 
teids. 



Fat. 



Carbo- 

hy- Ash. 
drates. 



Total 

Fuel 

Value. 

Cals. 



Ration cartridge, pea, beef, etc 

Blue ration campaigning food, a 

" b.. .. 

Red ration campaigning food, a 

" " •' " h 

Ration cartridge, potatoes, beef, etc. 

Emergency ration, a 

" •' h 

Emergency ration, a 

b 

Nao meat food 

Army rations 

Standard emergency ration 



Arctic food 

Tanty emergency ration . . . 
F-.\ Food Company's stew. 



Grams 
241 
169 

78 
122 

77 
283 
120 

"3 
121 

127 

437 
661 
418 
270 
49 
423 
475 
964 



Grams. 


Grams. 


34-2 


52-9 


7b.i 


37-5 


I 


5-6 


33-8 


26.2 


1.2 


5-° 


117.9 


62.3 


14.2 


56.1 


1-9 


8.2 


4-S 


71.8 


5-7 


8-3 


231-3 


56-9 


420.2 


101.2 


23.6 


129.6 


17.0 


50.6 


°-S 


3-2 


30-7 


7S-I 


313-S 


60.2 j 


638.0 


149.2 



42.0 

9.0 

23.1 

18-5 

23.0 

12-6 

29.6 

32-7 
32.6 

15-3 
90.1 

84-3 
9°-5 
54-a 
i°-5 
167.3 
48.6 

114-5 



Grams. 

98.0 

37-9 
46.9 

37-8 
46.6 

76-4 
II. 9 
68.0 

6-7 
94-8 
46.2 

47-9 
160.3 

137-0 
34-0 

119. J 
41.9 

52-5 



Grams, 

13-9 

8.,S 
1-4 
5-7 

1-2 

13. s 
7-8 
2.2 
5-4 

2.9 

12. 5 

7-4 
14.0 
10.6 

0.8 
30.1 
10.8 

9.8 



* Maine Exp. Sta.. Bui. 75, p. 103. 



1071 

432 

436 

496 

424 

772 

617 

622 

776 

•;S8 

1328 

1542 

2198 

1402 

254 

2430 

1482 

2460 



202 FOOD INSPECTION AND AN A LYSIS. 



REFERENCES ON FLESH FOODS. 



Andrews, O. W. Flesh Foods. London, 1900. 

Atken, W. On the Animal Alkaloids. London, 1890. 

Baillei, L. Traite de I'lnspection des Viandes. 

Balland, a. The Composition of Fish, Crustaceans and Molluscs. Compt. rend., 

1898, 126, 1721. 
BiGELOW, W. D. Meat and Meat Products. U. S. Dept. of Agric, Bureau of Chem- 
istry, Bui. 65, p. 7. 
Brieger, L. Untersuchung ueber Ptomaine. Berlin, 1885. 
CoBBOLD, T. S. Internal Parasites of Domestic Animals. 

Parasites of Man. 

Entozoa of Man and Animals. London, 1865. 

Denaeyer. La Composition des Peptones de Viande, 1896. 

Douglas's Encyclopasdia for Bacon Curers, Meat Inspectors, Local Authority 

Officers, etc. Wm. Douglas & Sons, London. 
DtTFF, Jas. C. Manufacture of Sausages. New York, 1899. 
Falck, C. Das Fleisch. Marburg, 1880. 

FiscHODER, F. Leitfaden der Praktischen Fleischbeshau. Berlin, 1899. 
Gautier, a. Les Toxines. Paris, 1896. 

Grindley, H. S. Losses in Cooking Meat. Exp. Sta. Bui. 102. 
GuENTHER. The Study of Fishes. 
HoFMANN. Lehrbuch der Zoochemie. 
Langworthy, C. F. Fish as Food. Farmer's Bui. 85. 
Lebben, S. Preservation and Coloring of Meat Produce. Berlin, 190T. 
Leuckart. Human Parasites. 
Mallet, J. W. Physiological Effect of Creatine and Creatinine, and their Value as 

Nutrients. U. S. Dept. of Agric, Off. of Exp. Sta., Bui. 66. 
Mitchell, C. A. Flesh Foods. London, 1900. 

McGu-L, A. Commercial Beef Extracts. Canada Inland Rev. Dept., Bui. 63. 
OsTERTAG. Handbuch der Fleischbeshau. 
Salmon, D. E. Inspection of Meats for Animal Parasites. Bui. 19, Bureau of An. 

Ind. 
Schmidt -MuLHElM. Handbuch der Fleischkunde. Leipsic, 1884. 
Vaughan, V. C, and Novy', F. G. Cellular Toxines. 
Walley, Thos. a Practical Guide to Meat Inspection. 
Wiley, H. W. Separation of Flesh Bases from Proteids by Bromine. U. S. Dept. of 

Agric, Div. of Chem., Bui. 54. 
Chemical Composition of the Carcasses of Pigs. U. S. Dept. of Agric, Bureau of 

Chemistry, Bui. 53. 
Woods, C. D. Meats, Composition and Cooking. Farmer's Bui. 34. 

Alabama Exp. Station, Bui. 81. Meat Inspection. 

Missouri Exp. Station, Bui. 25. Composition of Flesh of Cattle. 

Preser\'ed Meats. U. S. Dept. of Agric, Bur. of Chem., Bui. 13, part 10. 

Zeitschrift fur Fleisch und Milch Hygiene, 1891 ct seq. 



CHAPTER VIII. 



EGGS. 



Nature and Composition. — Though eggs of various birds are used to 
some extent as food, it is the egg of the hen that is in universal use for 
this purpose, and therefore the one which is here for the most part dis- 
cussed, bearing in mind that the structure and composition of all varieties 
of birds' eggs are closely analogous. 

Fig. 55 shows the longitudinal section of a hen's egg. 

3 i ff 

b 

' '" ' ' "*'' H/ 

If \W/ " / 
v\ , ^ 

Fig. 55.— Longitudinal Section of a Hen's Egg. a. Shell; b, Double Membrane of Shell; 
c, Air-chamber; d, Outer, or Fluid Albuminous Layer; e, Thick, Middle Albuminous 
Layer; /, Inner Albuminous Layer; g. Membrane of the Chalaza; hit, the Chalaza; 
i. Vitelline Membrane; /, Germ; k, Yollc; /, Latebra. (After Mace.) 

The average weight of a hen's egg is 60 grams, of which the shell 
weighs about 6, the white 36, and the yolk 18. Roughly it contains 70% 
of water, 12% of albumin, and 12% of fat. 

The shell, according to Konig, has the following composition: 

Calcium carbonate 89-97% 

Magnesium carbonate o- 2% 

Calcium and magnesium phosphate 0.5- 5% 

Organic substances 2.0- 5% 

203 



.^ 




204 



FOOD INSPECTION /tND ANALYSIS. 



The mean percentage composition of the eggs of the hen, duck, and 
plover are, according to Konig, as follows: 



Water. 
Per Cent. 



Proteids, 
Percent. 



Fat. 
Per Cent. 



Nitrogen- 
free Sub- 
stance 
Per Cent. 



Salts 
Per Cent. 



In the Dry Sub- 
stance. 



Nitrogen 
Per Cent. 



Fat 
Per Cent. 



Hen's egg 

Duck's egg 

Plover's egg 

White of hen's egg. 
Yolk " " 



73-67 
71. II 

74-43 
85-75 
50-79 



12-55 
12.24 

10-75 
12.67 
16.24 



15-49 

11.66 

0.25 

31-75 



0-55 
0.13 



1. 12 
1. 16 
0.98 

0.59 
1.09 



7.66 
6.78 

6-75 

14-25 

5-30 



45-99 
53-62 

45-78 
1.78 

64-43 



The Egg-white. — The white of egg has a specific gravity of 1.045, 
and its reaction is always alkaline. It is a transparent, albuminous fluid 
inclosed in a framework of thin membrane. The fibrous portion of 
the membrane is insoluble in water and in dilute acetic acid. 

The composition of the fluid substance of the white of egg, according 
to Lehmann, is as follows: 

Water 82 to 88% 

Solids 13-3% (mean) 

Proteids 12-2% " 

Sugar o-S% " 

Fats, alkaline sOaps, lecithin, cholesterin traces 

Inorganic residue o . 66% 

The proteid substance is for the most part albumin, with a small 
amount of globuhn. 

According to Osborne and Campbell* the nitrogen compounds of 
the white of egg are four in number, which they name ovalbumin, ovo- 
mucin, conalbumin, and ovomucoid. No sharp and distinct separation 
of these bodies has yet been made. 

Ovalbumin (albumin) is the chief constituent, and forms by far the 
largest portion of the protein of the egg-white. In 2.5% solution in water, 
ovalbumin starts to coagulate at 60°, and yields a dense coagulum at 64°. 
Stronger solutions require a somewhat higher temperature for coagulation. 

Ovomucin is a globulin-like substance, precipitated from egg-white 
by dilution with water. It is partly soluble in strong sodium chloride 
solution. WTien dried and washed with alcohol, it is a light white powder. 

Conalbumin bears a close resemblance to ovalbumin, but coagulates 

* Jour. Am Chem Soc, 22 (igoo). p. 422. 



EGGS. 



205 



in dilute salt solution at a lower temperature (below 60°), and the coagu- 
lum is more flocculent than that of ovalbumin. 

Ovomucoid is not coagulable by heat, and may thus be separated 
(imperfectly) by fihering out all the coagulable proteids. 

The last two compounds exist in very small amounts only. 

Preparation of Albumin.* — By beating up the white of egg in water, 
the salts and the albumin are dissolved, while the fibrous portion is insolu- 
ble and is removed by filtration. The filtrate is then treated with a slight 
excess of basic lead acetate, the precipitate decomposed by treatment with 
carbon dioxide, and the lead removed by hydrogen sulphide. The solu- 
tion is warmed cautiously to 60° C, thus beginning to coagulate the 
albumin, a small part of which, coming down in a ilaky form, carries 
with it the lead sulphide. On filtering or pouring off the supernatant 
liquid after cooling, one obtains a colorless solution of the albumin, which 
is evaporated to dryness below 40°. The albumin is obtained in the form 
of transparent yellowish, horny scales, which may be pulverized in a 
mortar, if desired. Its specific gravity is 1.262. It is tasteless, odorless, 
and neutral in reaction, and slowly soluble in water. 

The Egg-yolk. — This is much more complex in composition than 
the white. Halliburton thus enumerates the constituents of the yolk: 

(a) Proteids. — Vitellin, the chief one, a globulin resembling myosin. 
Albumin, in small quantities. 

Nuclein, combined chiefly with the iron present. 

(b) Fats. — Olein, palmitin, and stearin. 
A yellow lipochrome or lutein. 

(c) Carbohydrates. — Grape sugar in small quantities. 

((/) Other Organic Constituents. — Lecithin, a phosphorized nitroge- 
nous body allied both to the fats and to the proteids. 

Cerebrin. 

Cholesterin. 

(e) Inorganic Salts, the most abundant of which is potassium chloride. 
Gobley gives the following composition to the egg-yolk: 



Vitellin 

Nuclein 

Cerebrin 

Lecithin 

Glycerol phosphoric acid. 



Per Cent. Per Cent. 

. 15-8 Cholesterin 0.4 

• 1-5 Fats 20.3 

. 0.3 Coloring matters 0.5 

7.2 Salts i.o 

. 1.2 Water 51.8 



* .Mien, Com. Org. ,\nal., Vol. IV, p. 42. 



2o6 



FOOD INSPECTION /IND AN/t LYSIS. 



Osborne and Campbell,* as the result of long and careful expen- 
ments, consider the protein of egg-yolk to be largely if not wholly a lecithin 
compound, having properties of a globulin, and soluble in sodium chloride 
solution. 

The fat of the egg yolk, which is used in ointments, has the following 
characteristics according to Spaeth : t 

Specific gravity at ioo° C 0.881 

Iodine number 68.48 

Reichert-Meissl value 0.66 

Refractive index at 25° C. (on butyro-refractometer scale) 68.5 

Melting-points of fatty acids 36° C. 

Iodine number of fatty acids 72.6 

The mineral content of the egg is thus shown by Konig: 
COMPOSITION OF THE ASH OF EGGS. 



Ash of 
the Dry 

Sub- 
stance. 



Potash. 



Soda. 



Lime. 



Mag- 
nesia. 



Iron 
Oxide. 



Phos- 
phoric 
Acid. 



Sul- 
phuric 
Acid. 



Silica. 



Chlo- 
rine. 



Hen's egg: entire., 
white. . 
yolk... 



3-48 
4.61 
2.91 



17-37 

31-41 

9.29 



22.87 

31-57 

5-87 



10.91 

2.78 

13-04 



1. 14 
2-79 
2 13 



0-39 

0-57 
1-65 



37.62 

4.41 

65.46 



0.32 
2.12 



0.31 
1.06 
0.86 



8.98 

28.82 

I -95 



The following analyses of eggs were made by Wood and Merrill : % 
AVERAGE WEIGHTS OF EGGS AND PARTS AS PREPARED FOR ANALYSIS. 





Weight 

as 
Received. 


Weight Boiled. 


Shell 
(Refuse). 


White. 






Shell 
(Refuse). 


White. 


Yolk. 


Total.' 


Yolk. 


Turkey 

Goose 

Duck 

Guinea fowl. . . 


Grams. 

105 -5 

190-4 

70 6 

40.2 


Grams. 
II. 7 
24.1 

7-2 

5-6 


Grams. 
60.1 
98-5 
36-5 
20.9 


Grams. 

30-9 
64.8 
24.4 
12.5 


Grams. 

102.7 

187.4 

68.1 

39-0 


Per Cent. 

II-4 
12.8 
10.6 
14-4 


Per Cent. 

56-5 
52.6 

53-6 
53-6 


Per Cent. 
30.1 
34.6 
35-8 
32.0 



' Shrinkage due to loss in preparation and cooking. 



* Jour. Am. Chem. See, XXII, 1900, p. 413. 
t .\bst. Analyst, 1896, p. 233. 
X Maine Exp. Sta., Bui. 75, p. 90. 



EGGS. 
COMPOSITION OF EGGS. 



207 



^s 



u 
















is 




86 


7 


48 


3 


73 


3 


63 


S 


86 


3 


44 


I 


69 


5 


sq 


7 


«7 





45 


8 


70 


■; 


60 


9 


86 


6 


49 


7 


72 


8 


60 


6 


86 


2 


49 


5 


73 


7 


05 


5 



Protein. 



.sx 



1 


■i 

< 


Trace 


0.8 


32-9 


1.2 


II. 2 


0.9 


9-7 
Trace 


0.8 
0.8 


36.2 


1-3 


14.4 


I.O 


12-3 
Trace 


0.9 
0.8 


36.2 


1.2 


I4-S 


1.0 


12-5 


0.8 


Trace 


0.8 


31.8 


1.2 


12.0 


0.9 


9.9 
0.2 


0.7 
0.6 


i2,-i 


I.I 


i°-5 


1 .0 


9-3 


0.9 



I? 



Turkey- 



Goose 



Duck- 



Guinea fowl- 



Hen— 



white 

yolk 

entire edible portion. 

as purchased 

white 

yolk 

entire edible portion. 

as purchased 

white - . 

yolk 

entire edible portion. 

as purchased 

-white 

yolk , 

entire edible portion. 

as purchased 

white 

yolk 

entire edible portion, 
as purchased 



13-8 



14.2 



13-7 



16.9 



II . 
17- 
13- 
II. 
II. 



5 
4 
4 
6 
6 
17-3 
13-8 
II-5 
II. I 
16.8 
13-3 
11-5 
.6 

-7 
■S 
.2 

12-3 
15-7 



II. 
16. 

13- 
II. 



13- 
II. 



"■5 
17.6 
14.2 
12.2 
12.9 
18.4 

I5-I 
12.9 
12.2 
16.8 
14.0 
12. 1 
12.6 
17-3 
14-3 
II. 9 

13-0 
16. 1 

14.8 
I3-I 



Cal. 

323 

187s 

850 

735 

I97S 
985 
860 

315 
1980 

985 
880 

325 
1800 

875 
730 



METHODS OF ANALYSIS. 

Preparation of the Sample.* — The egg is first weighed as a whole and 
afterwards boiled hard, cooled, and again weighed. The shell, white, and 
yolk are then carefully separated and each weighed. After rejecting the 
shell, the yolk and white are separately reduced by a chopping-knife to 
the size of wheat grains. These portions are dried partially at a tem- 
perature not exceeding 45°, weighed, and afterwards ground to a fine 
powder in a mortar. 

Determinations of water, fat, ash, and total nitrogen are made in practi- 
cally the same manner as with flesh foods. 

Little attention has been paid as yet to the complete separation and 
determination of the nitrogen compounds in the white and yolk, and it 
is customary in most cases to express the protein of the whole as NX6.25. 

Determination of Lecithin. — Wiley's Method.'^ — The whole egg, ex- 
cluding the shell, is placed in a flask with a reflux condenser, and boiled for 
six hours with absolute alcohol. The alcohol is then evaporated off, and 
the residue treated in like manner for ten hours with ether. After evaporat- 

* Woods and Merrill, Maine E.xp Sta., Bui. 75, p. 92. 

t Principles and Practice of Agricultural .Analysis, Vol. Ill, p. 431. 



2o8 FOOD INSPECTION AND ANALYSIS. 

ing off the ether, the dry residue is rubbed to a fine powder, placed in an 
extractor and treated with pure ether for ten hours. The ether extract 
thus secured is oxidized, after removal of the ether, by fusion with mixed 
sodium and potassium carbonates, and the phosphorus is determined in 
the usual way as magnesium pyrophosphate. The amount of lecithin 
is obtained by muhiplying the weight of magnesium pyrophosphate by 
the factor 7.2703, on the basis of Hoppe-Seyler's formula for lecithin: 
C,,H„„NPO,. 

If, for example, an amount of organic phosphorus yielding 0.0S4S 
gram of magnesium pyrophosphate is found in 54 grams of egg exclusive 
of shell, then 0.0848X7.2703 = 0.61652 and 0.61652X100-^54=1.14. 
Therefore the percentage of lecithin in the egg is 1.14. 

Preservation of Eggs. — Owing to the porous nature of the shell, the 
moisture of the contents gradually grows less by evaporation, and the egg 
loses in weight. Air also passes in through the shell pores, carrying 
various microbes, which result in ultimate decomposition and spoiling 
of the egg. Nature has provided the shell with a thin surface coating of 
mucilaginous matter, which, however, is easily washed off. This coating 
tends to partially close the pores, and for best results in keeping should 
not be removed by washing. 

Eggs are commonly preserved by protecting them as far as possible 
from the air. This is acconiphshed in a variety of ways, the most common 
being to pack the eggs in salt or bran, so that the packing medium fills 
up the interstices between the eggs. Eggs thus packed will keep con- 
siderably longer then when exposed to the air. A solution of salt is some- 
times employed, and also lime water, the eggs being simply packed in 
the solution. The use of hme water is, however, open to the serious objec- 
tion that a disagreeable odor and taste are imparted to the eggs. 

Eggs are sometimes coated with gelatin, vaseline, wax, or gum, so as 
to cover ihem with an impervious layer, either by dipping them in the coat- 
ing medium, or by varnishing or otherwise applying the substance to the 
egg shell. By far the most efficacious egg coating has been shown by 
experiments in the North Dakota Experiment Station,* and also in Ger- 
many, to be sodium and potassium silicate, or water glass. The fresh 
eggs, preferably unwashed, are packed in a jar, and a 10% solution of 
water glass is poured over them. According to the North Dakota experi- 
ments, at the end of three and a half months, eggs packed in this manner 
the first of August appeared to be perfectly fresh. ^^ 

* Farmer's Bui. 103, U. S. Dept. of Agric, p. 18. 



EGGS. 209 

One drawback to this method is that eggs so treated break more easily 
on boiling, but this may be prevented by carefully piercing the shell with 
a strong needle. 

Cadet de Vanx has proposed immersing the egg in boihng water for 
twenty seconds, the result being that a very thin layer of the egg-white 
next the shell becomes coagulated, thus forming an impervious coating 
inside the shell. 

Physical Examination of Eggs. — Various physical tests have been 
prescribed for ascertaining the approximate age of an egg. Thus, accord- 
ing to Delarne, if the egg, when placed in a 10% salt solution, sinks to the 
bottom, it may be considered perfectly fresh; if it remains immersed in 
the hquid, it is to be considered at least three days old; and if it rises to 
the surface and floats thereon it is more than five days old. This test 
is a very rough one, and is useful only for eggs that have been kept in the 
air. Preserved eggs cannot be gauged by this means. 

The best method of examining eggs for freshness consists in interposing 
the egg between a bright light and the eye. If the egg is fresh, it will 
show a perfectly uniform rose-colored tint, without dark spots, the air- 
chamber being small and occupying about one-twentieth the capacity of 
the egg. If the egg is not fresh, it will appear more or less cloudy, being 
darker as the egg grows older, becoming in extreme cases opaque. At 
the same time the air-chamber grows larger as the age increases. 

Desiccated Egg. — It is possible to evaporate to drj'ness the contents 
of the egg to form a powder, the keeping qualities of which far exceed 
that of ordinary eggs, while it forms a concentrated food which lends 
itself much more readily to transportation than does the fresh egg in the 
shell. Several brands of desiccated egg are on the market, which from 
their analyses are undoubtedly genuine. The following are analyses 
of two of them, one (A) made by the Bureau of Chemistry, the other (B) 
by the Massachusetts State Board of HeaUh : 

A. B. 

Water 6.80 5.95 

Protein (NX 6.25) 45-20 48.15 

Protein by difference 5 1 ■ 20 

Fat 38.5 40.56 

Ash 3.5 5.34 

Egg Substitutes. — There have been many preparations in powdered 
form sold under this name, nearly all claiming to contain all the ingredients 



2IO FOOD INSPECTION AND A N/4 LYSIS. 

of eggs, but most of them falling far short of these claims. Some of them, 
as for instance those made frorn desiccated skimmed milk, do contain 
nitrogenous matter, but as a rule httle if any fat. 

Two samples of "egg substitute" sold in Massachusetts were analyzed 
with the following results : * 

A. B. 

Protein 16.94 18.72 

Fat 3.43 3-40 

Water 6.71 7.01 

Corn-starch, salts, and color- 
ing matter 72.92 70-87 

A ten-cent package of sample A, weighing about 2 ounces, was alleged 
to be equivalent to 12 eggs. Starch furnished the chief ingredient in 
both samples. 

One of the most flagrant examples of fraud in this connection was a 
product sold under the name "N'egg," advertised to contain the nutritive 
equivalent of the whites and yolks of a dozen eggs, "their composition 
being based on careful scientific analysis of natural eggs." It was put 
up in two small boxes, one containing a white and the other a yellow 
dr>' powder. Both were entirely devoid of nitrogen, and consisted of 
nearly pure tapioca starch with a little common salt, the color of the 
"yolk" being due to Victoria yellow. 

Some egg substitutes are sold under the name of "custard powders," 
and are alleged to take the place of eggs in cooking. These are variously 
made up of mixtures of skim-milk powder, coloring matter, and baking 
powder ingredients as shown from the following analyses:! 

CUSTARD POWDERS. 



Starch 

Albuminous compounds 

Soluble coloring matter 

Baking soda 

Tartaric acid 

Phosphates 

Carbonates of lime and magnesia . 

Chlorides and sulphates , 

Water 

Ash 



86.25 
0-59 



11.83 

0-4S 



84-45 
0.58 
0.08 



13.69 
0.38 



5i-°3 
6.01 



15-33 
13.69 

0.24 
2.70 

11.00 



26.38 
2.96 

50.70 
i°-33 



9-63 



52-32 
6.00 



22.11 
11-37 



8.20 



53-82 
5.06 

26.71 
6. 19 



8.22 



* An. Rep. Mass. State Board of Health, 1895, p. 675. 
t Food and Sanitation, Nov. 25, 1893. 



EGGS. 211 



REFERENCES ON EGGS. 

Langworthy, C. F. Eggs and their Uses as Food. Farmer's Bui. 128. 
Osborne, T. B., and Campbell, G. F. Proteids of the Egg Yolk. Jour. Am. Chem. 
Soc, XXII, page 413. 

Protein Constituents of Egg White. Jour. Am. Chem. Soc, XXII, page 422. 

Snyder, H. Digestibility of Potatoes and Eggs. E.xp. Sta. Bui. 43, page 20. 



Farmer's Bui. 87. Food Value of Eggs, page 24. 
" " 103. Preserving Eggs. 



CHAPTER IX. 

CEREALS AND THEIR PRODUCTS, LEGUMES, VEGETABLES, 

AND FRUITS. 



The chief points of difference in composition between the animal 
foods already treated of, and those of the vegetable kingdom, are apparent 
in the relative amounts of proteids and carbohydrates. The proteids 
present in the cereals and vegetables differ materially both in character 
and amount from those in the flesh foods, being as a rule present to a 
much greater extent in the meats than in the grains and vegetables. The 
leguminous foods, such as peas, beuns, and lentils, are, however somewhat 
exceptional in this respect, being comparatively high in nitrogenous 
content. 

The carbohydrates, which in the flesh foods are almost entirely lack- 
ing, and in milk and its products are present to a small extent only, form 
the most important and abundant class of constituents in the vegetable 
foods. 

The composition of the principal cereal grains is tabulated as follows 
by VilHer and CoUin: 



Wheat. 


Barley. 


Rye. 


Oats. 


Rice. 


Com. 


Millet. 


13-65 


13-77 


15.06 


12.37 


13. II 


13.12 


11.66 


12-35 


II. 14 


11.52 


10.41 


7-«5 


9-85 


9-25 


1-75 


2.16 


1-79 


■;-32 


0.88 


4.62 


3-5° 


1-45 


1.56 


0-95 


i.gr 




2.46 




2-38 


1.70 


4.86 


1-79 


f 16.52 


3-38 


[65-95 


64.08 


61.67 


62.00 


54-08 




62.57 




2-53 


5-31 


2.01 


II. 19 


0.63 


2.49 


7-29 


1. 81 


2.69 


1.81 


3.02 


1. 01 


I-51 


2-35 



Buck- 
wheat. 



Water 

Nitrogenous substances 

Fat 

Sugar 

Gum and dextrin 

Starch 

Cellulose 

Ash 



12.93 

10.30 

2.81 

55-81 

16.43 
2.72 



The following results of the analyses of cereal grains are summarized 
from the work of the Division of Chemistry, United States Department 
of Agriculture : * 



* Bulletin 13, part 9. 



CEREALS, LEGUMES, yEGETABLES, AND FRUITS. 
CEREAL GRAINS. 



213 



Num- 
ber of 
Analy- 
ses. 



Weight 

Ker- Moist- 
nei.s , 
Grams. 



Pro- 
teids. 


Ether 
Ex- 
tract. 


It. 52 


2.67 


10.86 


2.06 


"■55 
8.^8 
9.88 


5.06 
2.94 
4-17 


15-05 


6.14 


9.10 


0-93 


12.15 


4-33 


7-95 
8.02 
7.18 


1.65 
1.96 
0.26 


18.99 
8.40 


2.30 
1. 16 


12.43 


1-65 


17-15 
8.58 


2.50 
0.28 


12.23 


1-77 


14-52 

8.58 

12.08 


2.26 

°-73 
1.78 



Crude 

Fiber. 



Ash. 






Wet 
Gluten 



Dry 
Gluten. 



Barley: 

Mean 

Buckwheat: 
Mean 

Corn, domestic: 
Maximum . . . . , 
Minimum .... 
Mean , 

Oats, domestic: 

Ma.ximum 

Minimum . 

Mean 

Rice: 

UnhuUed 

Unpolished .. . 
Polished 

Rye, domestic: 

Ma.ximum. 

Minimum . 

Mean 

Wheat, domestic: 

Maximum 

Minimum. 

Mean 

Wheat, foreign: 

Maximum 

Minimum. . . . 
Mean 



14 



533 
069 

312: 
608 

979, 



.038 
.918 

■929 

-466, 
•132' 

.201 
-932 
-493 

.190 
■125 
.866 

-723 
.250 
.076 



6-47 
12.31 

12.32 

9-58 

i°-93 

13.02 

7.87 

10.06 

10.2 
II. 8 
12.34 

11-45 

9-54 

10.62 

14-53 

7. II 

10.62 

12.97 

8.52 

11.47 



3-81 
10-57 

2.00 
1. 00 
1. 71 

16.65 

8-57 
12.07 

10.42 

0-93 
0.40 

2.50 
1-65 
2.09 

3-72 
1.70 

2-36 

2.89 
1.87 
2. 28 



2.87 
1.85 

1-55 
1. 19 
1.36 

4-37 
--47 
3-46 

4-09 

1-15 
0.46 



2.41 
1. 71 
1.92 

2-35 
1.40 
1.82 

2.04 
1.67 
1-73 



72.66 

63-34 

75-07 
68.97 

71-95 

61-44 
53-70 
58-75 

65.60 
76.05 
79-36 

75-36 
63.61 

71-37 

76.05 
66.67 
71- 

76.14 
67.01 
70.66 



39-05 
12-33 
26.46 

32-57 
18.72 

25-36 






14.65 

4-70 

10.31 

12-33 
7.00 
9.82 



Balland * gives the following percentage composition of beans, lentils, 
and peas: 





Beans. 


Lentils. 


Peas. 




Min. 


Max. 


Min. 


Max. 


Min. Max. 


Water 


10. 10 

13.81 

0.98 

52-91 
2.46 
2.38 


20.40 

25-46 

2.46 

60. 98 

4.62 

4.20 


11.70 

20.42 

0.58 

56-07 

2.96 

1.99 


13-50 

24-24 

1-45 

62.45 

3-56 

2.66 


10.60 

18.88 

1.22 

56.21 

2.90 

2.26 


14.20 


Nitrogenous substances 

Fat 


22.48 
1.40 


Sugars and starches. 

Cellulose 


61.10 

5-52 
3-50 


Ash 





■ Jour. Pharm. Chem., 1S97, pp. 196, 197. 



214 FOOD INSPECTION AND ANALYSIS. 

The composition of potatoes, according to Balland,* is as follows: 





Water. 


Nitroge- 
nous 
Sub- 
stances. 


Fat. 


Sugar 

and 

Starches. 


Cellulose. 


Ash. 


Normal state — minimum . . 

maximum. . 

Dried — minimum . . 


66. lo 
80.60 


1-43 
2.81 

5-98 
13-24 


0.04 
0.14 
0.18 
0.56 


15-58 
29.85 
80.28 
89.78 


0-37 
0.68 
1.40 
3.06 


0.44 
1. 18 
1.66 






4-38 







The composition of the common vegetables, fruits, and berries is thus 
given by Atwater and Br}'ant.t 



VEGETABLES. 



Asparagus — 
Beans, dried — 
Beans.fresh Lima 

Beets, fresh — _ 

Cabbage — 

Carrot, fresh — 

Celery — 

Cauliflower — 
Cucumber — 

Lettuce — 

Mushrooms — 
Onion, fresh — 

Parsnip — • 
Pumpkin — 
Radish- 
Rhubarb — 
Squash — 

Tomato, fresh — 
Turnip — 



as purchased 

as purchased. . . 
-edible portion . . 
as purchased. . . 
edible portion. . 
as purchased. . . 
edible |)ortion . . 

as purchased 

edible portion . . 
as purchased. . . 
edible portion . . 
as purchased. . . 
as purchased. . . 
edible portion. . 
as purchased. . . 
edible portion . . 

as purchased 

as purchased . . . 
edible portion . . 
as purchased . . . 
eciible portion. . 

as purchased 

edible portion. . 
as purchased. . . 
edible portion. . 
as purchased. . . 
edible portion. . 
as purchased. . . 
edible portion. . 
as purchased. . . 
as purchased. . . 
edible portion. . 
as purchased. . . 






3 
II 



24 
'16 



IS 
3 
3 

4 



27 
19 



S5-0 



20.0 
i5-° 



20.0 
20.0 



15-° 
15-° 



10. o 
20.0 



50.0 
30.0 



40.0 
50.0 



30.0 























^ 


^ 


94.0 


1.8 


12.6 


22.5 


68.5 


7-1 


30.8 


3-2 


«7-S 


1.6 


70.0 


1-3 


91-5 


1.6 


77-7 


1-4 


88.2 


I.I 


70.6 


-9 


94-5 


I.I 


75-b 


-9 


92.3 


1.8 


95-4 


.8 


81. 1 


-7 


94-7 


I.2- 


80. s 


I.O 


88.1 


3-5 


87.6 


1.6 


78-9 


1-4 


83-0 


1.6 


66.4 


1-3 


93-1 


1.0 


46.5 


-5 


91.8 


1-3 


64-3 


-9 


94-4 


.6 


56.6 


-4 


88.3 


1-4 


44-2 


-7 


94-3 


■9 


89.6 


1-3 


62.7 


•9 



fa 



2 3-3 
8 159-6 

7 J22.0 

9 



4-4 
1-7 



2-5 



•7 

•7 

I.I 



.8 



.6 
1-3 



{fl o * 

V ^ 03 
s 00 



105 
1605 

570 
255 
215 
170 

145 
125 
210 
160 

85 
70 
140 
80 
70 
90 

75 
210 

225 
205 
300 
240 
120 

60 
135 

95 
i°5 

65 
215 
i°5 
105 
185 
125 



* Jour. Pharm. Chem., 1897, pp. 298-300. 

t Bui. 28, Office of E.tp. Station U. S. Dept. of Agriculture. 



CEREALS, LEGUMES, VEGETABLES, AND FRUITS. 



215 



FRUITS. 









Oi 



^1 

— ^ 






■a is 



290 
220 
270 

255 
460 
300 
270 

345 

215 

265 
380 
45° 
335 
345 
205 

145 
185 
90 
240 
170 

295 
260 
200 
395 
37° 
370 
335 
255 
180 

17s 

140 

60 



Apples — 

Apricots — 

Bananas^ 

Blackberries — 
Cherries — 

Cranberries — 
Currants — 
Figs, fresh — 
Grapes^ 

Huckleberries- 
Lemons — 

Muskmclons — 

Oranges — 

Pears — 

Pineapple — 

Plums — 

Prunes — 

Raspberries — 
Strawberries — 

Watermelon — 



edible portion 
as purchased . . 
edible portion, 
as purchased. . 
edible portion, 
as purchased. . 
as purchased. . 
edible portion, 
as purchased.. . 
as purchased. . 
as purchased. . 
as purchased. . 
edible portion, 
as purchased. . 
-edible portion, 
edible portion, 
as purchased. . 
edible portion, 
as purchased. . 
edible portion, 
as purchased. . 
edible portion, 
as purchased. . 
edible portion, 
edible portion, 
as purchased. . 
edible portion, 
as purchased., 
as purchased. . 
edible portion, 
as purchased. . 
edible portion, 
as purchased. . 



29 
II- 



9 
16 



3 

I 

28 

5 



25 



23 
2 



22 
2 



•4 

-3 

I.I 

i.o 

1-3 
.8 

1.0 

-9 

-4 

1-5 

1-5 

1-3 

1.0 

.6 

1.0 

-7 
.6 



.6 
.6 

-5 

-4 

1.0 

-9 
-9 
-7 
1.0 
1.0 
•9 
-4 
.2 



1.6 



2-5 

.2 



1-5 



4-3 



-4 



2-9 

1-4 



The following analyses of apples made by Browne * are of interest. 
The first four analyses show the changes that occur in the composition 
of a Baldwin apple at different stages of its growth. Below these is 
given the average of the analysis of 160 samples, representing 2 7 varieties 
of apples. 

COMPOSITION OF A BALDWIN APPLE AT DIFFERENT PERIODS. 



Condition. 


Water. 


Solids. 


Invert 
Sugar. 


Su- 
crose. 


Total 
Sugar. 


Total. 

Sugar 
after In- 
version. 


Starch. 


Free 
Malic 
Acid. 


Ash. 


Sugar 
Co- 
efficient. 


Very green.. 1 81.53 

Green 79 -81 

Ripe 1 80.36 

Over-ripe. .. 80.30 


18.47 
20.19 
19.64 
19.70 


6.40 
6.46 
7.70 
8.81 


1-63 

4.05 
6.81 

5-26 


8-03 
10.51 

14-51 
14.07 


8. II 
10.72 
14.87 
14-35 


4.14 

3-67 
0.17 


1. 14 

0.65 
0.48 


0.27 

0.27 
0.28 


47.16 
53-IO 
75-71 
72.84 



* Penn. Dept. of Agriculture, Bulletin 58. 



2l6 



FOOD INSPECTION /fND ANALYSIS. 



AVERAGE COMPOSITION OF 27 VARIETIES OF APPLES. 

Water 83.57 

Solids 16.43 

Invert sugar 7.92 

Sucrose 3-99 

Total sugar 11. 91 

Total sugar after inversion 12.12 

Free malic acid 0.61 

Ash 0.27 

Sugar coefficient 73-/6 

The composition of the commoner nuts is shown in the following 
table:* 

NUTS. 






OS 



■5 to 



Almonds — 

Beechnuts — 

Brazil-nuts — 

Butternuts — 

Chestnuts, fresh — 

Cocoanuts — 

Filberts— 

Hickory-nuts — 

Peanuts — 

Pecans — 

Pistachios — 
Walnuts, Calif nia- 



edible portion, 
as purchased . . 
edible portion. 
as purchased. . 
edible portion, 
as purchased. . 
edible portion, 
as purchased. . 
edible portion, 
as purchased. . 
edible portion, 
as purchased. . 
edible portion, 
as purchased. . 
edible portion, 
as purchased. . 
edible portion, 
as purchased. . 
edible portion, 
as purchased. . 
edible portion, 
-edible portion, 
as purchased . . 



45-0 
40.8 
49.6 
86.'4 
16.0 
48.8 



24-5 



53-2 



4.0 

2-7 

4.0 

2-3 

5-3 
2.6 

4-4 
.6 

45 -o 

37-8 

14. 1 

7-2 

3-7 

1.8 

3 

I 



73- 



20.0 

"-5 

21.9 

13.0 

17.0 

8.6 

27.9 

3-8 

6.2 

5-^ 
5-7 
2.9 

iS-6 

7-5 
15-4 

5-8 
25.8 

19-5 

II. o 

5-2 
22.3 

18.4 

4-9 



54-9 
30.2 

57-4 
34-0 
66.8 

33-7 
61.2 

8 

5- 

4 
5° 
25 
65 
31 
67 
25 
38 
29 
71.2 

33-3 
54.0 
64.4 
17-3 



17-3 
9-5 

13-2 
7-8 
7.0 

3-5 

3 5 

-5 

42.1 

35-4 
27-9 
14-3 
13-0 

6.2 
II. 4 

4-3 



1.8 



1-4 



2.0 
I.I 

3-5 
2.1 

3-9 
2.0 
2.9 
-4 
1-3 
I.I 

1-7 
■9 

2-4 

I.I 

2.1 

.8 
2.0 
1-5 
1-5 

•7 
3-2 
1-7 

•5 



303° 
1660 

307 ^ 
1820 

3265 
1655 
3165 
430 
1125 

945 
2760 

1413 
329° 
157s 
3345 
1265 
2560 
1935 
3455 
1620 

2995 

3306 

885 



Vegetables and Fruits furnish a large and most important portion 
of our food supply, but are naturally not included in their fresh state 
among the foods examined by the public analyst for adulteration, hence 



* U. S. Dept. of Agric, Off. of Exp. Station, Bui. 28. 



CERE/iLS, LEGUMES, l/EGET/tBLES, AND FRUITS. 217 

but little space need be given them beyond a resume of their composition, 
and an outline of methods of proximate analysis applicable to their exam- 
ination for food values. When, however, these products undergo the 
various processes incidental to their treatment for long keeping, such 
as preserving, canning, drying, pickling, and mixing with other ingredients, 
it is then that many varieties of fraudulent adulteration are practiced. 
Vegetable foods thus prepared form the subject of a separate chapter. 
Besides the proximate components that commonly occur in vegetable 
products, there arc two other substances worthy of mention found in 
unripe vegetables and fruits, viz., inosite and pectose. 

Inosile, CsHi^O^HsO, is not a carbohydrate, but, according to Ham- 
mersten, is an aromatic compound. Besides occurring in unripe fruits, 
it is found in green asparagus and beans. 

Pectose is a substance the e.xact nature of which has not been fully 
determined, though it is thought to be a carbohydrate. It gives to unripe 
fruits and vegetables their peculiar hardness, and furnishes the basis for 
their gelatinous constituents. When the vegetable or fruit ripens, the 
insoluble pectose is transformed by the action of acids and possibly of 
ferments into pectin, a vegetable jelly, which gives to fruit juice the property 
of gelatinizing when boiled. 

Inulin, CeH,„05, is a starch-like substance, occurring in traces in 
chicory^ and in the tubers of the potato and of the artichoke. It is a white, 
starch-like powder, slightly soluble 'n cold, and readily soluble in hot 
water, and converted into levulose by boiling with water, or by the action 
of acids. 

METHODS OF PROXIMATE ANALYSIS. 

Preparation of the Sample. — Cereals and dry leguminous foods are 
prepared for analysis by grinding in a coffee- or spice-mill to such a 
degree of fineness that the powder will pass through a sieve with 60 meshes 
to the inch. Green vegetables, beets, green peas, etc., are best reduced 
to suitable form for analysis by running through a domestic grinding- 
machine of the kind ordinarily employed in the kitchen for grinding 
and shredding meats and vegetables, being by this means reduced to a 
pulp of uniform consistency. 

The following methods are based for the most part on those of the 
Association of Official Agricultural Chemists, employed for the analysis of 
foodstuffs with modifications.* 

* U. S. Dept. of Agric, Div. of Cfiem., Bui. 46, revised. 



2i8 FOOD INSPECTION AND ANALYSIS. 

Moisture. — From 2 to 3 grams of the finely divided substance are 
spread evenly over the bottom of a shallow platinum dish or watch-glass, 
and dried at 100° C. in an air-oven for five hours. 

Ash. — The residue from the moisture determination (if a platinum 
dish has been used) is burned in the original dish to whiteness at the 
lowest possible red heat.* If a white ash cannot be obtained in this manner, 
exhaust the charred mass with water, collect the insoluble residue on a 
filter, bum, add this ash to the residue from the evaporation of the aque- 
ous extract, and heat the whole to a low redness till the ash is white or 
nearly so. 

Ether Extract. — 2 to 3 grams of the sample are dried as for the determin- 
ation of moisture, and extracted for sixteen hours with anhydrous, alcohol- 
free ether in a Soxhlet extractor. Dry the extract to constant weight, 
or the ether extract may be determined indirectly from the difference in 
weight of the dried substance before and after extraction, weighing it for 
convenience in the extraction tube. 

Proteids. — The total nitrogen is determined according to the Gunning 
method in the absence of nitrates, using 0.5 gram of the finely divided 
substance. The total proteids are calculated by multiplying the total 
nitrogen by the appropriate factor, which varies with the different cereals. 
The factors for the common cereals are as follows: wheat, 5.70; rye, 5.62; 
oats, 6.31; corn, 6.39; and barley, 5.82. 

Total Carbohydrates. — These are roughly determined by difference. 

Crude Fiber {Cellulose)^. — The residue from the determination of the 
ether extract is transferred to a 500-cc. flask and 200 cc. of boiling 1.25% 
sulphuric acid are added. Connect the flask with an inverted condenser, 
the tube of which passes only a short distance beyond the rubber stopper 
into the flask. Boil at once, and continue the boiling for thirty minutes. 
A blast of air conducted into the flask may serve to reduce the frothing 
of the liquid. Filter through paper, and wash with boiling water till the 
washings are no longer acid. Rinse the substance back into the same flask 
with 200 cc. of a boiling 1.25% solution of sodium hydroxide, free, or nearly 
so, from sodium carbonate, boil at once, and continue the boiling for thirty 
minutes in the same manner as directed above for the treatment with acid. 
Filter on a tared iilter-paper and wash with boiling water till the wash- 
ings are neutral. Dry at 110° and weigh, after which incinerate com- 
pletely. The loss of weight is crude fiber. A blank experiment should 

* Observe the precautions indicated on page in about igniting cereals in platinum, 
t Modified from U. S. Dept. of Agric, Div. of Chem., Bui. 46. 



CEREALS, LEGUMES, l^EGET/tBLES, AND FRUITS. 219 

be made on a second piece of filter-paper to show the loss occasioned by 
treatment with alkali, and the necessary correction should be made. 

The filter used for the first filtration may be linen, one of the forms of 
glass wool or asbestos filters, or any other form that secures clear and 
reasonably rapid filtration. A gooch was originally prescribed for the 
final filtration, but with many substances is apt fo clog. The solutions 
of sulphuric acid and sodium hydroxide arc to be made up of the 
specified strength determined accurately by titration, and not merely 
from specific gravity. 

CARBOHYDRATES OF CEREALS AND VEGETABLES. 

Classification. — As a rule the same carbohydrates are found in all 
cereals, being present, however, in varj-ing proportions. By far the greater 
part of the carbohydrate content of cereals is starch, the other carbohydrates 
being comparatively small in amount, so that in rough work it is sometimes 
customary, though incorrect, to assume the entire amount of so-called 
"nitrogen-free extract" or carbohydrates (as determined by difference) 
to be starch. 

The carbohydrates occurring in cereals may be classified as follows: 



Principal carbohydrates 
of cereals; 



f Starch 

Insoluble < Cellulose 

[ Pentosans 

f Sucrose 

[Soluble Dextrose 

Dextrin 



. Raffinose (traces) 



Starch (CsHKiOi)^. — Pure starch is a glistening, white, granular 
powder having a peculiar feeling when rubbed between the thumb and 
finger. It is a very hygroscopic, commercial starch containing about 18% 
of moisture. Starch is very widely distributed in the vegetable kingdom, 
occurring in almost every plant at some stage in its growth. 

Starch is insoluble in cold water, alcohol, and ether; it is soluble in 
hot water, though not without change. By boiling with dilute acids, 
starch is first converted by hydrolysis into a mixture of dextrin and 
maltose, and finally by prolonged boiling into dextrose. Malt extract 
also hydrolizes starch in solution. 

Detection. — Starch is best detected, when present to any appreciable 
extent in any mixture, by boiling a portion of the sample in water, cooling, 
and applying a solution of iodine. A characteristic blue color is pro- 
duced if starch is present. Very small amounts of starch are best iden- 



220 FOOD INSPECTION AND ANALYSIS. 

tified in powdered mixtures by applying a drop of a solution of iodine 
to the dry powder on a microscope slide, or, better, to the powder previously 
rubbed out with water on a slide under a cover-glass ; the starch granules, 
if present, will be colored intensely blue by the iodine, and are at once 
rendered apparent when viewed through the microscope. 

Though the cereal and vegetable starches, whatever their origin, are 
identical chemically, the various starch granules have certain character- 
istics, when viewed under the microscope, that render their identifi- 
cation easy in most cases. A knowledge of the microscopical appear- 
ance of the common vegetable starches is of the utmost importance to 
the public analyst, who frequently finds them as adulterants of various 
foods, such as coffee, cocoa, spices, etc. For microscopical examination, 
powdered samples should be ground fine enough to pass through a 60 or 
80 mesh sieve. 

Classification. — The microscopical appearance of the starch granules 
of various grains and vegetables differ in form, size, and often in their 
manner of grouping. Thus, at the outset, the common starches may be 
divided as to the microscopical form of their granules into three classes, 
viz., circular, irregularly oval, and polygonal. To the first class, in which 
the starch granule has in general the circular disk form, belong rye, wheat, 
and barley. Representing the second or irregularly elliptical class are 
the pea, bean, potato, and arrowroot. In the third, or polygonal class, 
should be included corn, oats, buckwheat, and rice. In thus character- 
izing the distinguishing forms as circu'ar, oval, and polygonal, it should 
be borne in mind that while the tendency'of the most typical starch granules 
in each class, when viewed in normal position, is toward the circular, the 
oval, or the polygonal as the case may be, it is not by any means true that 
all or even most of the granules in any one instance perfectly conform 
to one of these shapes throughout. Thus, circular wheat granules, when 
viewed edgewise, will appear elliptical, and are often distorted in shape, 
especially when roasted; and polygonal buckwheat granules may in 
many instances have such obtuse angles as to appear circular. It is the 
general trend of all the starches toward one or another of these shapes 
that suggests the classification. 

The identification of the various starches morphologically is 'ndeed 
the most natural and ready method. Not only the character of the starch, 
but also its approximate amount, when present in mixtures, can in many 
instances be ascertained by a careful examination with the microscope. 
The analyst should be provided with samples of starches of known 



CEREALS, LEGUMES, yEGET/IBLES, AND hRUITS. 221 

purity conveniently at hand, and in all doubtful cases these should be 
referred to for comparison. 

Wheal Slarch (Fig. 152, PI. VIII). — This starch is very commonly used 
as an adulterant of mustard, ginger, cocoa, coffee, and other foods. Its 
granules are circular disks, occurring for the most part in two sizes, of 
which the larger vary from 0.021 mm. to 0.041 mm. in diameter, while the 
smaller average about 0.005 ^^^- The smaller granules are grouped 
irregularly in and around the larger, there being six to ten of the former 
to one of the latter. The larger granules are, however, the most distinctly 
characteristic, and are usually readily recognized in a mixture, not only 
by their shape, but by reason of the concentric rings with which they are 
provided, and which are generally but not always apparent. 

Barley Starch (Fig. 124, PI. I) — This much resembles wheat, in that it 
has two sizes of circular granules, but both sizes are respectively smaller 
than those of wheat, though present in about the same proportion. The 
larger granules vary from 0.013 mm. to 0.035 n^"''- i" diameter, while the 
smaller average 0.003 mm. The concentric rings are less apparent in 
the barley than in the wheat. 

Rye Starch (Fig. 148, PI. VII) has also two sizes of circular disk-like 
granules, but the larger vary from 0.025 mm. to 0.05 mm. in diameter, 
and are considerably larger than the corresponding wheat granules. The 
smaller granules average about 0.004 rnm- in diameter. There is also a 
much larger proportion of small granules present than in the case of wheat. 
The concentric rings are often very distinct in the large rye starch 
grains, and many of these show cross-shaped rifts in the center. 

Corn Slarch (Fig. 133, PI. IV). — This starch is a common adulterant 
of spices, cocoa, and other foods. It is placed in a series of four cereal 
starches whose granules are polygonal, and all of which show more or 
less tendency to arrange themselves in close contact side by side in 
masses suggestive of a tessellated or mosaic floor. Arranged in order 
of the size of their grains, these starches arc: Corn, oats, buckwheat, 
and rice. Corn starch granules tend toward the hexagonal in shape, 
varying from 0.007 rnm. to 0.023 mm. in diameter, and having very 
marked rifted hila. They are most readily recognized in any mixture, 
and from their size are readily distinguishable from the other polygonal 
starches. 

Oat Slarch (Fig. 139, PI. V). — The granules of this starch, averaging 
0.004 mni. in diameter, are less regular in shape than the com, besides 
being smaller. They have no rings or hila, and arrange themselves in 



222 FOOD INSPECTION AND ANALYSIS. 

little groups or masses that at first sight might be mistaken for 'arge 
grains; careful examination, however, shows the divid'ng lines. 

Buckwheat Starch (Fig. 128, PI. II, and Fig. 129, PL III). — This is a 
very common adulterant of many spices, especially pepper, which, as shown 
in Fig. 256, PI. XXXIV, it much resembles in the manner in which its 
aggregate masses of granules group themselves. The individual granules 
are quite uniform in size, averaging about 0.006 mm. in diameter, and 
the masses are usually with difficulty broken up into individual grains, 
requiring considerable rubbing out under the cover-glass. 

Rice Starch (Fig. 143, PI. VI). — The granules of rice starch are con- 
siderably smaller than those of buckwheat, and are readily distinguished 
from the latter also by reason of the fact that they are much more sharply 
pointed (having less obtuse angles), and are grouped in smaller masses. 

Starches of the Pea and Bean. — The starches of these legumes much 
resemble each other, and are with difficulty distinguished one from the 
other (see Fig. 164, PI. XI, and Fig. 154, PL IX). The granules are 
more nearly oval than most other starches, and have both concentric 
rings and ver)' marked hila. The starch of the pea is perhaps more 
regular and uniform in the size and form of its granules than that of the 
bean. Both peas and beans roasted are commonly used as adulterants of 
coffee. 

Arrowroot. — There are many varieties of this starch, including Jamaica, 
Bermuda, East Indian, Australian, and others, all having certain varia- 
tions in form and size, but resembling each other in a general way. 
Fig. 167, PI. XII, shows the Bermuda arrowroot, the granules of which 
are somewhat egg-shaped, being usually smaller at one end than the 
other, and having rifted hila near the small end. 

Potato Starch (Fig. 165, PL XII). — This starch has large, irregularly 
oval granules, with very apparent hila situated eccentrically near one 
end, and with rings around the hilum. Tlic granules are often 0.07 mm. 
in large diameter. Fig. 134, PL IV, and Fig. 166, PL XII, show corn and 
potato starch when viewed with polarized light with crossed Nicol prisms, 
the specimens being mounted in Canada balsam. 

Tapioca Starch. — The granules of this starch, as shown in Fig. 168, PI. 
Xll, are more uniform in size throughout than those already described, 
averaging about 0.018 mm. in diameter, and being quite smoothly circular, 
without concentric rings, but having a distinctly dotted hilum in the center. 
Many of the grains are cup-shaped, as if a segment of the circle had been 
removed. 



CEREALS, LEGUMES, VEGETABLES, AND FRUITS. 223 

Sago Starch (Fig. 172, PI. XIII). — The granules of sago starch vary 
much in size, and might be called irregularly ellipsoidal in shape, being 
provided with numerous protuberances. Some of them have indistinct 
concentric rings, and in some, but not all, a hilum is apparent, usually 
near one end of the granule. 

Microscopical Appearance of Starches with Polarized Light. — Certain 
of the starches show a play of colors with polarized light and a selcnite 
plate, especially those whose granules have some sort of hilum. This 
is particularly striking in such starches as corn, tapioca, potato, and arrow- 
root. Blyth has made the phenomenon a means of classification of the 
starches, but in the writer's experience the microscopical appearance and 
relative size of the starch granules under normal light is the simplest and 
best means of identifying their character. For viewing with polarized 
light, the samples are best mounted in Canada balsam, in which medium 
they appear much less distinctly than with water, for examination with 
ordinary illumination. 

Estimation of Starch. — Direct Acid Conversion. — By this method the 
hemicellulose, if present, or such of the carbohydrates as are capable of 
being converted to sugar, are reckoned in with the starch. Where little 
or none of the insoluble carbohydrates other than starch are present, as 
for instance in the case of commercial starches, this method is sufficiently 
accurate. 

E.xhaust 3 grams of the finely divided substance on a fine but rapidly 
acting filter with ether by washing with 5 successive portions of 10 cc. 
each, and wash the residue first with 150 cc. of 10% alcohol and then 
with a little strong alcohol. Transfer by washing to a flask with 200 cc. 
of water and 20 cc. of hydrochloric acid (specific gravity 1.125), connect 
with a reflux condenser, and heat the flask in boihng water for 2\ hours. 
Cool, and carefully neutrahze with sodium hydroxide, clarifying if neces- 
sary with alumina cream. Mix well, make up the volume to 500 cc, 
filter, and determine the dextrose in an aliquot part of the filtrate by 
any of the methods for dextrose. Convert dextrose to starch by the 
factor o.g. 

Diastase Method. — By this method the hemicellulose is not con- 
verted, only the starch being acted upon. Hence for exact work in the 
presence of other insoluble carbohydrates this method is to be recom- 
mended. Under the action of diastase, starch is first converted into 
maltose and dextrin, and finally into dextrose, in somewhat the following 
manner: 



224 FOOD INSPECTION AND ANALYSIS. 

i2CeH,A+4H20 = 4Ci2H,,0„+2Ci,H2„0,„ 

Starch Maltose Dextrin 

Ci2H,,0„ + H,0 = 2C„H„0, Ci2H2„0,„+ 2H,0 = 2CeH,20, 

Maltose Dextrose Dextrin Dextrose 

Exhaust 3 grams of the finely divided substance with ether and alcohol 
as in the acid-conversion method, wash the residue into a 250-cc. flask 
with 50 cc. of water and immerse the flask in a boiling-water bath, stirring 
the contents constantly until the starch gelatinizes. Cool to 55° C, add 
20 to 40 cc. of malt extract (prepared as below), and maintain at this 
temperature until the solution no longer gives the starch reaction with 
iodine as shown by microscopic examination.* This treatment with malt 
converts the starch into dextrin and maltose. After cooling, make up to 
250 cc, filter, transfer 200 cc. of the filtrate to a 500-cc. flask, and add 
20 cc. of hydrochloric acid (specific gravity 1.125), connect with a reflux 
condenser and heat in a boiling-water bath for two and one-half hours, 
by which process the dextrin and maltose are converted into dextrose. 
Cool, neutralize carefully with sodium hydroxide (avoiding an excess), 
clarify if necessary with 10 to 20 cc. of alumina cream (p. 482), and 
make up to 500 cc. Mix well, pour through a dr}' filter, and determine 
the dextrose in an aliquot part of the filtrate, using the factor 0.9 for 
converting dextrose to starch. Correct for the copper reducing power 
of the malt extract, as below. 

Preparation oj Malt Extract. — Dry malted barley can be readily ob- 
tained from any brewery. Treat 15 to 20 grams of freshly pulverized 
malt for several hours with 100 cc. of water, shaking occasionally. Filter 
the solution, and add two or three drops of chloroform to prevent the 
growth of fungi. Determine the amount of dextrose in a given quantity 
of the malt extract, after boihng with acid, etc., as in the starch determina- 
tion, and make the proper correction. 

Cellulose forms the framework, or skeleton, of all vegetable organisms, 
being, next to water, the most abundant substance in the vegetable 
kingdom. 

Pure cellulose is white, translucent, and of fibrous or silky texture. 
It is insoluble in water, alcohol, and ether, but dissolves readily in an 
ammoniacal solution of cupric hydroxid known as Schweitzer's Reagent f 
or "cuprammonia." 

* If after an hour's digestion the microscope indicates the presence of unconverted 
starch, heat in a boiling-water bath a second time, cool to 55° and again treat with a fresh 
portion of malt extract as before. 

"f Prepared as directed on p. Si. 



CEREALS, LEGUMES, yEGETABLES, AND FRUITS. i^S 

Cellulose turns violet when treated with chloriodide of zinc, and blue 
when treated with sulphuric acid and iodine in potassium iodide (p. 79). 

The "crude fiber" as determined in foods, being the portion that 
resists the action of hot dilute acid and alkali, is composed largely of 
cellulose. 

The Pentosans are of comparatively small importance, and have been 
little studied. They are amorphous in character, insoluble in water, 
but soluble in dilute alkali, and are capable of conversion by boiling with 
dilute acids into so-called pentose sugars, the best known of which are 
xylose and arabinose, corresponding to the pentoses xylan and araban 
respectively. Strictly speaking the term " hemicellulose " is the more 
appropriate generic term to apply to the insoluble carbohydrate bodies 
which are capable of hydrolysis by acids to sugars, inasmuch as there 
are insoluble bodies besides the pentosans that may thus be converted 
into sugar, such as the hexosans, hydrolyzed by acid to hexose sugars, 
mannose, galactose, etc. The term "wood gum" is also used synony- 
mously with hemicellulose. Since the greater portion of these insoluble 
hydrolizable carbohydrates are pentosans, it is simpler to calculate them 
all as such. 

Determination of Pentosans. — Pentosans are determined either by 
hydrolyzing to reducing sugar, and estimating the latter as described on 
page 228 (Stone's method) or by calculation from the furfurol * yielded 
by them on distillation of the sample with hydrochloric acid, as carried 
out in the provisional method of the A. O. A. C.f as follows: 

Three grams of the material are placed in a flask, together with 100 cc. 
of 12% hydrochloric acid (specific gravity 1.06) and several pieces of 
recently heated pumice stone. The flask, placed upon wire gauze, is 
connected with a condenser, and heat applied, rather gently at first, using 
a gauze top to distribute the flame, and so regulated as to distill over 30 cc. 
in about ten minutes. The 30 cc. driven over are replaced by a like 
quantity of the dilute acid, and the process continued so long as the distillate 
gives a red color when applied to a filter-paper soaked in anilin acetate. 
To the completed distillate is gradually added a quantity of phloroglucin 
(free from diresorcin) dissolved in 12% hydrochloric acid, and the re- 

* Furfurol or furfuraldehyde (C^H^O.^) is the aldehyde of pyromucic acid. It is a color- 
less liquid, having an odor suggestive of cassia. Its boiling-point is 162° and its specific 
gravity 1.164. It is sparingly soluble in water and readily soluble in alcohol. Nearly 
half the tissue of ordinary bran, exclusive of proteids and starch, yields furfurol on distilla- 
tion with acid. 

f U. S. Dept. of .''igric., Div. of Chem., Bui. 46, p. 25. 



2 26 FOOD INSPECTION /IND ANALYSIS. 

suiting mixture is thoroughly stirred. The amount of phloroglucin used 
should be about double that of the furfurol expected. The solution 
first turns yellow, then greeny and very soon an amorphous greenish 
precipitate appears, which grows rapidly darker, till it finally becomes 
almost black. The solution is made up to 500 cc. with 12% hydrochloric 
acid and allowed to stand over night. 

The amorphous, black precipitate, a condensation product the exact 
composition of which is unknown, is filtered into a tared gooch through 
an asbestos felt, washed with 100 cc. of water, dried to constant weight 
by heating from three to four hours at 100°, cooled and weighed, the 
increase in weight being reckoned as phloroglucide. To calculate the 
furfurol from the phloroglucide, use the following formulae : 

Phloroglucide (less than and up to 0.2 gram) -h 1.82 = furfurol. 
Phloroglucide (from 0.2 to 0.3 gram) -^ 1.895 = furfurol. 
Phloroglucide (from 0.3 to 0.4 gram) -M.92 = furfurol. 
Phloroglucide (above 0.4 gram) -h 1.93 = furfurol. 

To calculate the furfurol to pentosan or pentose use the following 
formulae : 

I. (furfurol 0.0104) X 1.68 = xylan. 
II. (furfurol 0.0104) X 2.07 = araban. 

III. (furfurol 0.0104) X 1.88 = pentosan. 

IV. (furfurol 0.0104) Xi. 91 = xylose. 

V. (furfurol 0.0104) X 2.35 =arabinose. 
VI. (furfurol 0.0 1 04) X 2 . 1 3 = pentose. 

The reactions that take place are thought to be somewhat as follows : 
C,H,0,+ H,0 = QH,„0,. 

Pentosan Pentose 

C,H,„0, = C,HA+3H,0. 

Pentose Furfurol 

2C,H,0,+ C^HeO, = C,eH,20„+ H,0. 

Furfurol Phloroglucin Phloroglucide 

The theoretical yield of phloroglucide should be 2.22 parts to one of 
furfurol, but in practice this is never obtained. The varying factors for 
calculation as above given are based on experiment. 

The phloroglucin used should be free from diresorcin. To test for 
the latter, dissolve the reagent in acetic anhydride, heat nearly to boiling. 



CERE/tLS, LEGUMES, yEGETABLES, AND FRUITS. 



237 



and add a few drops of concentrated sulphuric acid. If more than a 
faint violet color is produced, the phloroglucin is unfit for use. 

SEPARATION AND DETERMINATION OF THE VARIOUS CARBOHYDRATES 
OF CEREALS, ETC. STONE'S METHOD. 

Stone has thus tabulated the results, of a series of analyses of various 
samples of wheat, llour, corn, and bread, in which he has separated the 
principal carbohydrates.* 

PERCENTAGES OF VARIOUS CARBOHYDRATES IN CERTAIN FOODSTUFFS. 



Whole wheat, I... 
Whole wheat, II. . 

Wheat flour, I 

Wheat flour, II. .. 

Corn 

Sugar-beet 

Bread (wheat, I). . 
Bread (wheat, II). 
Bread (flour, I). .. 
Bread (flour, II). . 
Com cake (maize) 



Sucrose. 


Invert 




Soluble 


Normal 


Pento- 




Sugar 




Starch. 


Starch. 


sans. 


0.52 


0.08 


0.27 


0.00 


30-94 


4-54 


0.72 


O-OO 


0.41 


0.00 


30-36 


4-37 


0.18 


0.00 


0.90 


0.00 


46.19 


0.00 


0.20 


0.00 


1.06 


0.00 


34-04 


0.00 


9.27 


0.00 


0.32 


0.00 


42-50 


5-14 


8.38 


0.07 


°:35 


0.00 


0.00 


4.89 


0.05 


0.32 


0.68 


I -.^7 


27-93 


4.16 


0.06 


°-il 


0.23 


2.36 


27.08 


4-34 


O.OI 


O.IO 


0.27 


1. 99 


34-70 


0.00 


°-i5 


0.38 


0.91 


1-74 


31-99 


0.00 


0.16 


0.19 


0.00 


2.80 


40-37 


3-54 



Crude 
Fiber. 



2.68 

2-51 
0.25 
0.25 

1-99 
1. 00 

2.70 
2.02 

0-34 
0.17 
2.22 



Determination of Cane Sugar. — 100 grams of the finely ground ma- 
terial are extracted by boiling under a reflux condenser with 500 cc. of 
95% alcohol for three hours, the alcoholic extract is filtered, evaporated 
nearly to dryness, and then taken up with a small amount of water, to 
separate the sugar from the oils and waxes dissolved by the alcohol. This 
aqueous solution is invariably dextro-rotary, and seldom contains any 
reducing sugar. If the latter is present, it is determined in an aliquot 
part of the aqueous solution with Fehling's solution, the result being 
calculated to dextrose. The remainder of the aqueous sugar solution, or 
the whole of it, if, as is almost always the case, dextrose is absent, is 
then inverted by heating with hydrochloric acid in the usual manner 
(page 483) and the sugar is estimated with Fehling's solution, calcu- 
lating the result to sucrose (page 497). 

Determination of Dextrin. — Digest the residue from the above alco- 
hoKc extraction from eighteen to twenty-four hours with 500 cc. of cold 
distilled water, shaking frequently. On filtering, a clear solution is ob- 



* Jour. Am. Chem. See., XIX, 1897, p. 183, and U. S. Dept. of Agric, Off. of Exp. Sta., 
Bui. 34. 



2 28 FOOD INSPECTION AND ANALYSIS. 

tained, which should be tested with iodine for soluble starch. If the 
latter is not found (which is nearly always the case), the solution is con- 
centrated to a small volume, avoiding a temperature higher than 80° to 
90°, and this is boiled under a reflux condenser for two hours with one- 
tenth its volume of hydrochloric acid (specific gravity 1.125). Deter- 
mine the dextrose by FehHng's solution and calculate to dextrin by the 
factor 0.9. Or, instead of submitting the concentrated aqueous extract to 
hydrolysis as above, the dextrin may be roughly determined gravimetrically 
therein by treating with several volume's of strong alcohol until no further 
precipitation is produced. The flocculent precipitate thus obtained is 
collected, dried, and weighed. 

Determination of Starch. — Dry in an oven the residue from the pre- 
ceding treatment and determine its quantitative relation to the original 
sample ; 2 grams are then accurately weighed and subjected to the dias- 
tase method of starch determination (page 223). 

Determination of Pentosans and Hemicelluloses. — The washed resi- 
due, left after filtering off the starch-containing solution from the process 
of heating with malt extract in the preceding starch determination, is 
boiled for an hour with 100 cc. of 1% hydrochloric acid, which converts 
all the pentosans into sugar. Filtet, and wash tlie residue thoroughly, 
make up the solution to 200 cc, and determine the sugar with Fehling's 
solution, calculating the results for xylan, assuming that the chief sugar 
formed is xylose. The reducing power of xylose is assumed to be 4.61 
milhgrams for each cubic centimeter of Fehling's solution. If the volu- 
metric Fehling method is used, 10 cc. of Fehling's solution are thus 
equivalent to 0.046 gram xylose. Xylose X 0.88 = xylan. 

Crude Fiber {Cellulose). — The residue from the last dilute acid 
hydrolysis is boiled with 200 cc. of 1.25% solution of sodium hydroxide 
for half an hour, fiUered, dried, and weighed. It is then ignited, and 
the weight of the ash deducted from the first weight. 

PROTEIDS OF CEREALS AND VEGETABLES. 

Different cereal and vegetable foods present considerable variations 
in the character and extent of their proteid constituents, and by no means 
all of the common vegetable foods have been studied in detail. 

Osborne, in connection with Voorhees and Chittenden, has made 
a careful study of the proteids of many of the cereals, of potatoes, and 
of peas. A brief outline only will be given in what follows of methods 



CEREALS, LEGUMES, I^EGETABLES, AND FRUITS. 229 

for separation of the vegetable proteids. For fuller details the reader 
is referred to the work of Osborne et al. in the American Chemical Journal, 
Vols. 13, 14, and 15, and to the Journal of the American Chemical Society, 
Vols. 17, 18, 19, and 20. 

Proteids Soluble in Water and Dilute Salt Solution. — By the action 
of various solvents it is possible to separate the different classes of pro- 
teids for examination or analysis. Thus water at first applied extracts 
certain of the soluble proteids, as does a weak salt solution. Osborne 
and Voorhees recommend the use of a 10% solution of sodium chloride 
as the first solvent to apply for separating vegetable proteids, shaking 
the finely ground material with twice its weight of the salt solution. The 
salt solution, after liltering, is then subjected to dialysis, the protcid matter 
thus separated out being a globulin, while that not precipitated on dialysis 
is assumed as the proteid matter of the substance soluble in water. Two 
albumins and a proteose are found in wheat to be thus soluble in water. 

If the proteids soluble in salt solution are to have their total nitrogen 
determined, they are completely precipitated from the solution by satu- 
rating with zinc or ammonium sulphate. 

There are thus two classes of proteids soluble in 10% salt solution: 
(a) globulins, insoluble in water alone, and {b) albumins and proteoses, 
which are soluble in water. 

Separation of Albumins, Proteoses, and Globulins. — Starting with the 
aqueous solution containing the albumins and proteoses, if present, the 
former are best separated according to Osborne and Vorhees by fractional 
coagulation, effected by heating at different temperatures, those that 
precipitate out at a temperature under 65° being first filtered out, and 
the filtrate submitted to a higher temperature not exceeding 85°. The 
two portions thus separated may be collected in filters, and their nitrogen 
separately determined. 

The proteose may be precipitated from the filtrate by saturating with 
ground salt, or by adding, first salt to the extent of 20%, and finally acetic 
acid. 

The globulins, precipitated in the original 10% salt solution by the 
process of dialysis as described, may themselves be separated by employing 
salt solution of varying strength as solvents.* 

Proteids Soluble in Dilute Alcohol, but Insoluble in Water. — The 
residue from the treatment with 10% sodium chloride is digested with 75% 
alcohol at about 46° C. for some time and filtered. The residue is further 
* Am. Chem. Jour., 13, p. 464. 



2 3© FOOD INSPECTION AND ANALYSIS. 

digested at about 60° vsith 759c alcohol three separate times. The evapo- 
rated filtrates contain the alcohol-soluble proteids. In this class are the 
hordein of barley, the gliadin of wheat and r}-e, and the zein of com. 

Proteids Insoluble in Water, Salt Solution, and Dilute Alcohol. — It is 
customar}' to determine the nitrogen in the final residue -nithout further 
attempt to separate the remaining proteid matter. It is, however, possi- 
ble to further extract with alkaline and acid solvents, if desired, which 
process, however, changes the nature of the proteids from that in 
which they originally exist in the substance. 

Character and Amount of Proteids in Wheat.* — The proteids of 
wheat, according to Osborne, are five in number as follows: 

Amount Present, 
Per Cent. 

_ , . , . ( Albumin (leucosin) 0.3100.4 

Soluble in water. j Proteose. 0.3 

Soluble i'.i 10 per cent XaCl: Globulin (edestin) 0.6 to 0.7 

Soluble in dilute alcohol: Gliadin 4. 25 

Insoluble in above: Glutenin 4.00 to 4.5 

Gluten. — This term is applied to the entire proteid content of wheat 
flour insoluble in water, and the value of flour for baking bread depends 
on the amount of gluten present. Gluten contains the two definite pro- 
teids gliadin and glutenin. Crude gluten is a complex mixture of many 
bodies, containing, besides the two proteids above named, small quan- 
tities of cellulose, mineral matter, lecithin, and starch. 

Wiley t recommends the following method for separating crude gluten 
from flour. Ten grams of the fine-ground flour are placed in a porcelain 
dish, well wet with nearly an equal weight of water at a temperature not 
to exceed 15°, and the mass worked into a ball with a spatula, taking 
care that none of it adheres to the walls of the dish. The ball of dough 
is allowed to stand for an hour, at the end of which time it is held in the 
hand and kneaded in a stream of cold water until the starch and soluble 
matter are removed. The ball of gluten thus obtained is placed in cold 
water, and allowed to remain for an hour, when it is removed, pressed as 
dr}- as possible between the hands, rolled into a ball, placed in a flat- 
bottomed dish, and weighed. The weight obtained is entered as moist 
gluten. The dish containing the ball of gluten is dried for twentj'-four 
hours on a water-bath, again weighed, and the weight of material obtained 
entered as dr}- gluten. 

* Am. Chem. Jour., XV, 392-471; XVI, 524. 
t .\gnc. .\nalysis. Vol. 3, p. 435. 



QERE/ILS, LEGUMES, yEGET/IBLES, AND FRUITS. 231 

Separation and Determination of Wheat Proteids. — Teller's Method.* — 
Non-gluten Nitrogen. — Two grams of the finely divided sample are mixed 
with about 15 cc. of 1% sa t solut on in a 250-cc. flask. The flask is shaken 
at intervals of ten minutes diring one hour, after which it is filled to the 
mark with the salt solution and al owed to- stand two hours. The super- 
natant liquid is then filtered through a dr)- filter into a dn,- flask, leaving 
most of the solid material in the flask, passing the first part through twice, 
if necessary, for a clear filtrate. With a pipette, exactly 50 cc. of clear 
filtrate are run into a 500-cc. Kjeldahl digestion-flask, 20 cc. of the usual 
reagent sulphuric acid for the Gunning process (p. 61) are added, and 
the contents of the flask brought to a gentle boil. After the water has 
been driven off and the acid has stopped foaming, the potassium sul- 
phate is added and the digestion completed. From the per cent of 
nitrogen thus obtained 0.2790 is deducted, this figure corresponding to 
the amount of gliadin soluble in 1% salt solution under the above con- 
ditions. The remainder is the percentage of non-gluten nitrogen. 

Gluten Nitrogen. — This is obtained by difference between the total 
nitrogen and the non-gluten nitrogen as above obtained, or by deducting 
the combined nitrogen of the edcstin, leucosin, and the amido-nitrogen 
from the total nitrogen. 

Edestin and Leucosin. — Edestin is a globulin belonging to the vegetable 
vitellins, and is precipitated from salt solutions by dilution, or by satu- 
ration with magnesium or ammonium sulphate, but not by saturating 
with sodium chloride. It is not coagulated below 100° C, but is partly 
precipitated by boiling. Leucosin is an albumin, coagulating at 52°, 
but precipitates from salt solution by saturating with sodium chloride 
or magnesium sulphate. 

To 50 cc. of the clear salt extract, obtained as described under non- 
gluten nitrogen, 250 cc. of pure 94% alcohol are added in a Kjeldahl 500-cc. 
digestion-flask, the contents thoroughly mixed, and allowed to stand 
over night. The precipitate is collected in a lo-cm. filter, which is 
returned to the flask and the nitrogen determined. This represents 
the nitrogen of the combined edestin and leucosin. These proteids 
may, however, be separated by coagulating the leucosin at 60°, and pre- 
cipitating the edestin by adding alcohol to 50 cc. of the clear filtrate, 
determining the nitrogen separately in each precipitate. 

Amido-nitrogen. — AUantoin, asparagin, choUn, and betaine are nitrog- 
enous bases present in wheat. 

* Ark. Exp. Sta. Bui. 42, p. 96. 



232 FOOD INSPECTION AND ANALYSIS. 

Ten cc. of a io% solution of pure phosphotungstic acid are added 
to loo cc. of the clear salt extract as above obtained, thus precipitating 
all the proteids, which are allowed to settle preferably over night. Fil- 
ter, and determine the nitrogen in the clear iiltrate. The filtrate 
should be tested with a little of the phosphotungstic acid reagent to 
make sure that all the proteids have been separated. In some 
cases, as in bran for instance, more than lo cc. of the reagent are 
necessary. 

Glladin is dissolved most readily from flour by hot dilute alcohol, 
but is entirely insoluble in absolute alcohol. One gram of the mate- 
rial is extracted with loo cc. of hot 75% alcohol, by shaking the mixture 
thoroughly in a flask, and heating for an hour at a temperature just below 
the boiling-point of alcohol, with occasional shaking. After standing 
for an hour, the hot liquid is decanted upon a lo-cm. filter, and 25 cc. 
of the hot alcohol are added to the residue and shaken, after which the 
residue is again allowed to settle, and the liquid decanted. This is 
repeated six times. The remainder of the alcohol is then driven off 
by evaporation, and the nitrogen determined in the residue. The 
difference between the total nitrogen and the nitrogen thus obtained, 
gives the nitrogen of the alcoholic extract, which includes the amides. 
Subtracting the latter, or amido-nitrogen, the remainder is the gliadin 
nitrogen. 

Glutenin Nitrogen. — This is the difference between the gluten nitro- 
gen and the gliadin nitrogen. 

The factor by which the nitrogen should be multiplied in determin- 
ing the various proteids, according to Osborne and Voorhees, is 5.7 for 
wheat. 

Proteids of the Common Cereals and Vegetables. — Osborne and his 
coworkers have made a detailed study of the proteid constituents not 
only of wheat as above outhned, but of other common grains and vegeta- 
bles, and the results of these investigations may be thus briefly sum- 
marized: 

Proteids of rye : * 

Per Cent. 

Insoluble in salt solution 2 .44 

Soluble in alcohol, gUadin 4.00 

Soluble in water, leucosin 0.43 

Soluble in salt solution: I p^^jg'^g | 1.76 

8^ 

• Jour. Am. Chem. Soc, 17, page 429. 



CEREALS, LEGUMES, I^EGETABLES, AND FRUITS. 233 

Protcids of barley:* Per Cent. 

„ , , , . . ( Lcucosin ) „ , 

Soluble m water: -I p^^^^^^^ f °-3 

Soluble in salt solution, edestin i .95 

Soluble in dilute alcohol, hordein 4.00 

Insoluble in water, salt solution, and alcohol 4 . 50 

Proteids of com : f 

Soluble in water: Proteose 0.06 

i Very soluble globulin 0.04 

Soluble in salt solution : < Maysin o . 25 

( Edestin i . 10 

Soluble in dilute alcohol : Zein 5 • 00 

Insoluble in above, but soluble in two-tenths per cent potash solution 3-i5 

Proteids of pea: % 

Soluble in salt solution: Globulins - , ,. ^.,. ' ■ 

/ Vicilin 3.00 

Soluble in water: Albumin, legumelin, proteose 2.03 



Proteids of Potato. § — Almost the whole proteid content of the potato 
consists of a globulin to which Osborne has applied the name "tuberin." 
Proteose is also present in very small amount. 

Composition of the Ash of Cereals and Vegetables. — A complete 
analysis showing the definite composition of the ash of cereals and 
vegetable products is not often necessary. When, however, this is to 
be done, it is of importance to obtain as large an amount of the ash as 
possible for examination, and to this end the dried, finely divided mate- 
rial is burnt in a mufifle at a low red heat in platinum dishes || of at least 
50 grams capacity, adding from time to time 25 grams of the material, 
whenever the bulk of the burnt residue is sufficiently reduced to admit 
of it. This is continued until enough ash is obtained for the work in 
hand, and the heat is applied till the product is light gray in color. 

The detection and estimation of the various common ash ingredients 
are carried out by the qualitative and quantitative processes commonly 
employed in mineral analysis, and will not be given here. 

The following table 1[ shows the composition of the pure ash of com- 
mon cereals: 



* Jour. Am. Chem. Soc, 17, p. 539. 

7 Ibid., 19, p. 525. 

t Ibid., 18, p. 583; 20, pp. 348 and 410. 

§ Ibid., 18, p. 575. 

II On account of the high content of phosphoric acid in cereals it is unsafe to ignite in 
platinum over a free flame. It may safely be done with caution at a moderate heat in a 
muffle. See p. 56. 

% V. S. Dept. of Agric, Bur. of Chem., Bui. 13, part 9, p. 1212. 



234 



FOOD INSPECTION AND ANALYSIS. 
COMPOSITION OF ASH OF CEREALS. 



KjO. NajO. CaO. 



MgO. 



FeaOa. 



P.Oj. 



SOa. 


CI. 


O.OI 


0.00 


0.52 


0.58 


0.22 


0.56 


0.48 


1.02 


0.44 


0.00 


0.24 


0.80 


3-59 


0.67 



SiOz. 



Wheat (Canada) 

Rve (Minnesota) 

Birley (U. S.) 

Oats (U. S.) 

Com (TJ. S.) 

Rice, polished (Guatemala). 
Buckwheat (U. S.) 



24-03 
27.60I 

24-15 
15-91 
33-92 
20.84 

35-15 



9-55 
4.64 
6.42 

4-38 

7.72 

13.98 

2.26 



3-5° 

S-56 
2.44 
4.09 
3.18 

4- 
6.62 



13-24 

11-73 

8.23 

7-1 

17-99 

9.60 

20-55 



0.52 
5-23 
0-33 
0.20 
0.50 
0.89 
1.68 



46.87 
41.81 
35-47 
24.34 
35-25 
43-21 
24.09 



2.28 

2.45 
22.30 
42.64 
1. 00 
6.14 
5-54 



Teller * obtained the following results of ash analyses of flour, bran, 
and wheat: 

ASH OF WHEAT PRODUCTS. 



Patent 
Flour. 



Straight 
Flour. 



Low 
Grade. 



Bran. 



Wheat. 



Silica 

Alumina 

Ferric oxide 

Potash 

Soda 

Lime 

Magnesia 

Phosphoric acid. 

Sulphur trioxide. . .. 

Chlorine 

Zinc oxide 

Sum 

Per cent of total ash 



2-33 

.41 

•47 

3S-50 

0.00 

5-59 

4-39 

48-05 

.16 



99-90 
-31 



1.28 

-15 
.26 

36-31 
0.00 

5-65 

6.44 

49-32 

-52 

.04 



-50 
.12 

-25 

32-27 
0.00 

4-51 

9-33 

53-10 

.00 



99-97 
.40 



100.08 
.70 



-97 

.07 

.27 

28.19 

0.00 

2.50 

14.76 

52.18 

.10 

.01 

-27 



99-95 



1.04 

.11 

.27 

29.70 

0.00 

3.10 

13-23 

52-14 

.22 

.01 

.24 



100.06 



1.62 



Konig gives the following analyses of the ash of various leguminous 
and other vegetables : 



^ 












, s 


Pis 




•?■« 


.HS 


J2 


i^ 


•s5 


1 


2 


< 


0, 



en 








•a 


•c 


X 









Ik 


f- < 


CU 


0-57 


.^8.74 


0.86 


36-43 


1. 18 


17-33 


0.82 


8.45 


1-03 


12.46 


0.81 


12.71 



M 




2-53 


0.73 


3-49 


0.86 


6.49 


2.13 


3-17 


2.38 


b.72 


2.47 


11.19 


1.87 



Beans . . 

Peas 

Potatoes, 
Beets. . . 
Carrots . 
Turnips. 



15 
29 

53 
15 
II 

32 



3-57 
2-73, 
3-77 
6-44' 
5-58 
8.01 



42.49 
41.79 
60.37 
54-02 
35-21 
45-40 



1-34 

0.96 

2.62 

15-90 

22.07 

9- 



4-73 7-°8 
4-99 7-96 
" — 4.69 

4-54 
4-73 



2-57 

4.12 

11.42 

10.60 



3-69 



1-57 
1-54 
3-11 
8.40 

5-13 
5.01 



* Ark. Exp. Sta. Bui. 42. 



CEREALS, LEGUMES, (VEGETABLES, AND FRUITS. 



235 



FLOUR. 

Flour is the term applied lo the finely ground and bolted substance 
of wheat and other grains, though, unless otherwise qualified, by the 
term "flour" is generally understood that of wheat. In the process 
of manufacture, the dried wheat or grain is first crushed between mill- 
stones, forming the comparatively coarse product known as whole meal. 
This, by bolting, may be separated simply into flour and bran, but in the 
crude milling of years ago at least three products were usually obtained 
from wheat, viz., fine flour, coarser shorts, or middlings, and bran. 

In the improved modern processes of milling, which meet the de- 
mands for the very finest flour, as well as other grades, the material is 
subjected to repeated sifting and grinding between grooved rollers, with 
the result that it is possible to turn out as many as ten separate grades 
of flour, as is shown by the following record of a mill near Trieste: 

Groats,* A and B 2 per cent 

Flour, No. o 5 " 



Bran 
Loss. 



12 

6 

6 

5 " 

5 " 
14 " 

9 " 

5 " 
10 
18 
_3 " 

100 percent 



41 per cent extra flour 



y 38 per cent medium and common 
j 21 per cent waste 



Analyses of these separated products made by C. A. Pillsbur}' are 
as follows: 



Water. 



Ash. 



Phosphoric 
Acid. 



Nitrogen. 



Proteids 
Calculated. 



Groats *. 
No. o.. 



9, coarse bran. 
10, fine bran 



10-57 

10-37 

10.23 

10.47 

10.07 

-J. 24 

9.66 

11.12 

10.99 

9.86 

9.71 

II. 01 



0.42 

0.43 
0.41 

1.03 
1.02 
1. 19 
0.69 
1.04 
0.81 
1. 01 

7-32 
4.21 



0.20 
0.14 
0.21 
0.22 
0.17 
0.25 



■35 
-24 
.21 
•36 
.14 
■70 



2.24 
1.68 
1.68 
1.72 
1.72 
1.74 
1.80 
1.84 
1.80 
1.90 



20 



-65 
.76 
.76 
.02 
.02 
■15 
•54 
•79 
•54 
.18 
.69 
.16 



* Masses of the interior of the berry. 



236 



FOOD INSPECTION AND ANALYSIS. 



In this country the common practice of most mills is to produce about 
three grades of flour, somewhat as follows: 



100 lbs. wheat. 



Patent or middlings flour, 55 lbs. 
Bakers' or family " 15 " 

Low-grade or bran " 6 " 
Bran, shorts, and waste 

(used principally for 

cattle food), 24 " 



Graliam Flour, or whole-wheat flour, is made from the unbolted meal 
of wheat, ground as finely as possible. It is actually a mixture of flour 
and bran. 

Composition of Common Flours. — The following analyses are col- 
lated and summarized from Bulletin 13, part 9 of the Bureau of Chem- 
istry: 



No. of 
Analy- 
ses. 


Moisture. 


Proteids, 
NX 6.25. 


Proteids, 
NXS.70. 


Moist 
Gluten. 


40 
19 


12.77 
12.28 


IO-S5 
10.18 


9.62 
9.28 


25-97 
24-55 


14 


11.69 


12.28 


11.20 


34-7° 


3 

I 


12-57 
II. 41 


7-13 
13-56 






I 
I 


10. q2 
11.89 


7-5° 
8-75 







Dry 
Gluten. 



Patent wheat flour 

Common market wheat flour. 

Bakers' and family flour 

Indian-corn flour 

Rye flour 

Barley flour 

Buckwheat flour 



9.99 

9.21 

i3-°7 



Ether 


Ash. 


Carbohy- 


Crude 


Extract. 




NX6.2S- 


Fiber. 


1.02 


0.44 


74.76 


0.21 


1-3° 


0.61 


75-63 


0.28 


1.30 


°-57 


73-87 


0.22 


1-33 


0.61 


78-36 


0.87 


1-97 


I-5S 


73-37 


1.86 


0.89 


0.86 


80.50 


0.67 


1.58 


1.85 


75-41 


0.52 



Calculated 
Calories of 
Combus- 
tion. 



Patent wheat flour 

Common market wheat flour 
Bakers' and family flour. . . . 

Indian-corn flour 

Rye flour 

Barley flour 

Buckwheat flour 



3858 
3882 
3929 

3837 



3854 



Inspection of Flour. — In some of the larger cities authorized flour 
inspectors are appointed, whose business it is to examine the product and 
pass upon its quality. To such inspectors the local dealers submit sam- 
ples, which the inspectors gauge as to color, soundness, weight, etc., com- 
paring them usually with a series of graded samples, and stamping ox 



CEREALS, LEGUMES, (VEGETABLES, AND FRUITS. 237 

branding them officially with the date as well as the grade. Marked 
quotations also are based on the standard terms adopted. The names 
of the various grades differ with the locality. In St. Louis the following 
names are adopted in order of their quality, viz., Patent, Extra Fancy, 
Fancy, Choice, and Family. 

Such systems of inspection are under the auspices of local dealers, 
being organized and maintained for their own protection, and have not 
as yet been the subject of state or even municipal supervision, as in the 
case of meat inspection. The grade or quality of flour is determined 
largely by its appearance and color, by its fineness as indicated by rub- 
bing between the fingers, by its odor, and by the so-called ' ' doughing 
test," which consists in kneading the flour with water under fixed con- 
ditions, and noting its tenacity and elasticity. 

Adulteration of Flour. — Besides the substitution of cheaper or in- 
ferior grades for those of higher quality, the fraudulent admixture of 
cereals other than wheat is not uncommon in flour. Corn meal is some- 
times found as an adulterant of wheat flour. Its presence is best detected 
by the microscope, the difference between the wheat and corn starch 
being readily apparent. 

Finely ground mineral adulterants are said to have been used in flours, 
but no authentic instance of this kind has come to the writer's knowledge. 
Any considerable admixture of such a nature would be manifest in the 
increased ash. 

Alum in Flour. — The addition of alum to flour was formerly a common 
practice in Europe, both by miller and baker, for the purpose of improv- 
ing the appearance of inferior or slightly damaged flour. Hence it was 
frequently found in the cheaper grades of flour and bread. Now, how- 
ever, it is rarely if ever used for this purpose, and the presence of notable 
quantities of alum or its compounds in flour or bread is usually due to 
its use as an ingredient of leavening powders. 

Detection. — To detect alum in flour, mix about 10 grams of the sample 
in 10 cc. of water and add about i cc. of an alcoholic tincture of logwood 
(5 grams logwood digested in 100 cc. alcohol) and about i cc. of a sat- 
urated solution of ammonium carbonate. Stir the whole well together. 
If the sample is pure, the color will be a faint brown or pink, but if alum 
is present, a distinct lavender-blue color is produced, which should remain 
after heating for two hours in the water-oven. 

Alum may also be tested by the ammonium chloride method, described 
on page 263. 



238 



FOOD INSPECTION /IND ANALYSIS. 



The Cold-water Extract of Flour. — The amount of cold-water extract 
shows to some extent whether or not a flour has been damaged, because 
in cases of damaged flour the starch grains have usually suffered injury, 
rendering them to some extent soluble. Wanklyn specified the following 
method of determining the cold-water extract. 

One hundred grams of the flour are thoroughly mixed with distilled 
water in a graduated liter-flask, which is finally filled with water to the 
mark; the contents are thoroughly mingled by frequent shaking during 
six or eight hours, and allowed to stand over night. The supernatant 
liquid is then poured upon a filter. After rejecting the first few cubic 
centimeters of the filtrate, exactly 50 cc. are collected and evaporated to 
dryness in a tared platinum dish on the water-bath. The weight of 
the dried residue, multiplied by 20, gives the quantity of cold-water extract, 
which in a sound flour, according to Wanklyn, should not exceed 5%. 

Gluten Flour. — This preparation is primarily intended for the use 
of diabetics, from whose dietary carbohydrates must be excluded; hence 
its value for their purpose is determined by its low content in starch. 

The following analyses of commercial gluten preparations were made 
by Woods and Merrill.* 



Protein. 


.Fat. 


Carbohy- 
drates. 


16.88 


3-86 


76.80 


17.89 


5.20 


73-85 


15-31 


0.99 


82.52 


43-70 


1.60 


44.40 


53-60 


1.20 


34-50 


31-50 


1.40 


53-2° 



Ash. 



"Cooked gluten" 

Whole-wheat gluten . . 

"Glutine" 

Breakfast cereal gluten 
Plain gluten flour .... 
Self-raising flour 



2.46 
3.06 
1. 17 

0.70 
0.60 
3 -80 



Many brands of gluten flour are put on the market by dealers in so- 
called "health foods," and in many cases are represented to be practically 
free from starch. Thirteen samples of gluten flour were analyzed by 
the author in 1899, varying in price from 11 to 50 cents per pound. Of 
these, 3, the product of one manufacturer, contained less than 1% of 
starch, 3 contained from 10 to 20 per cent, while 7 contained from 56 to 
70 per cent of starch, the substance which, of all others, the diabetic patient 
tries to avoid. Some of these preparations were little better than whole- 
wheat flour. One of them, known as "Pure Vegetable Gluten," and sold 
for 50 cents per pound, was found on analysis to be made up as follows: 



* Maine Exp. Sta. Buls. 55 and 75. 



CEREALS, LEGUMES, yEGET/tBLES, AND FRUITS. 239 



Moisture 10 

Ash 2 

Fat 3 

Proteids 14 

Sugars I 

Dextrin 2 

Starch 56 

Undcrtcrmined 8 



78 
20 

25 
25 
70 

55 
55 



Ergot. — Ergot is a fungus growth that occasionally develops within 
the grain of rye and other cereals, and, unless care is taken, becomes 
ground with them in the preparation of meal and flour. Ergot contains 
alkaloids of a poisonous nature, and instances are on record of its acci- 
dental presence in cereal preparations causing serious injur}- to health. 
While most commonly found in rye, ergot occasionally grows in wheat. 
If flour or meal containing ergot be treated with a very dilute solution 
of anilin violet, the stain v.'ill be practically absorbed by the damaged 
particles of the grain, and resisted by the normal granules. If shaken 
with dilute alkali, a meal or flour contaminated with ergot is colored 
violet, which by treatment with acid turns red. A hot, alcoholic extract of 
flour containing ergot is colored red when treated with dilute sulphuric 
acid. 

Ergot in ground cereal preparations is best recognized under the 
microscope, appearing as a fine network of mostly colorless parenchyma 
cells, containing globules of fat (Fig. 56). Some of the cells are circular, 
others considerably elongated, and some contain a deep-brown coloring 
matter, which, when treated with ammonia, takes a violet-red color. 
Occasionally the cell walls appear of a dark color. If the suspected 
sample be treated with dilute anilin violet, as above described, the 
stained ergot fragments will be especially apparent under the micro- 
scope. 

Microscopical Examination of Flour and Meal. — A studv of the 
histology of the various cereal grains is beyond the scope of the present 
work, and the reader who wishes to pursue this branch of the subject 
is referred to the treatises of Vogl and Tsirsch and Osterlc. The charac- 
teristics of the tissues of the various ground cereal grains are quite dis- 
tinctive when carefully studied, sufiiciently so, at least, 'o serve to identify 
a particular grain, when its flour is submitted in its purity to examination. 



240 



FOOD INSPECTION /tND ANALYSIS. 



In a mixture of two or more flours, however the corresponding tissues 
of the different grains resemble each other so closely that it is by no means 
an easy task to distinguish them by the appearance of these tissues. In 
such a mixture the microscopical appearance of the starch furnishes 
the chief reliance on which to base a judgment as to the character of 
the grains. We have already seen that the various cereal starches differ 
considerably in morphology and mode of grouping from each other, 
and this is true to such an extent that the expert can readily identify them. 
Since starch furnishes much more than half the content of all ground 





A B 

Fig. 56.— .4, Transverse Section of the Ergot of Wheat under the Microscope ; B Powdered 
Wheat Ergot. (After Villiers and CoUin.'N 



cereals, any considerable admixture of one flour with another is nearly 
always rendered apparent by a careful study of the magnified starch 
grains, which form a large part of the field when viewed under the micro- 
scope. 

The character of the tissues differs with the fineness of the meal or 
flour. In the highest grade of fine flour there is but little of the seed 
skn, and the masses of cells forming the different layers of the grain 
are present usually in fragmentary form. The coarser the meal, the 
larger and better defined are the cefl walls, especially those of the pro- 
tein or aleurone layer, and the more abundant are the fragments oi the 
seed skin. 



CERB^LS, LEGUMES, yEGET.4BLES, ANU FRUITS. 



*4l 



"Wheat Flour or Meal. — Fig. 57 shows the elements typical of wheat 
meal. 

e are the long six-sided cells of the epicarp, with bead-like walls; 
next to these are the elongated cells, ct, "with similar bead-like walls, 
these cells usually running transversely to those of the epicarp; p are 
the single-celled hairs attached normally to a portion of the epicarp. 



i^xsl fin,-} : 




Fig. 57. — WTieat Flour under the Microscope, e, epicarp; p, hairs; ct, c't', transverse 
cells; t, tubular cells; b, brown seed coat; pi, masses of pigment; ec, sheath 
around the embrj'o; es, outer envelope of the sheath; co, cotyledon; jfv, fibro- 
vascular ducts; sc, thickened cells; a, starch; al, aleurone; ap, proteid layer. (After 
Villiers and Collin.) 

These hairs arc somewhat distinctive, being conical or slightly ■ tapering, 
often bent and enlarging into a bulb at the base. The thickness of the 
wall of the wheat hair is usually equal to the thickness of the lumen; 
sc are hardened or lignified cells of the mesocarp, often with inter- 
cellular spaces. The tubular cells, /, of the endocarp are rarely 
isolated, but more often attached to the transverse cells and running 
perpendicular thereto, h is the seed coat, of a yellowish or orange- 
brown color, having two layers, composed of ver)' thin-walled cells, 
crossing each other at right angles. Fragments of the hyaline layer 
h are often found un'ted with b^ts of the seed skin. A piece of 
the sheath or layer immediately surrounding the embn'o or germ 



242 



FOOD INSPECTION AND ANALYSIS. 



is shown at ec, es being a palisade-like layer lying outside the sheath. 
The aleurone cells, sometimes incorrectly termed gluten cells, are repre- 
sented at ap. These are polygonal, sometimes nearly square in plan 
view, and normally contain the aleurone grains al, but often are broken 
down, and, when seen in the flour, empty. The rounded, angular aleu- 
rone grains appear sometimes isolated and sometimes in masses. If 
there is danger of mistaking them for small starch grains, cochineal should 



9QoWFSo® 




Fig. 58. — Rye Meal under the Microscope, ee', epicarp; m, mesocarp; p, hairs; ct, trans- 
verse cells; ;, tubular cells; 5C, hardened cells of the mesocarp; bb', brown seed-coat 
envelopes; pi, pigment; jjv, fibro-vascular ducts; h, hyaline layer; ap, proteid 
layer; co, cotyledon; es, palisade cells of the outer embryo coating: cc, inner coat- 
ing of the embryo; 0, starch; al, aleurone. (.\fter Villiers and Collin.) 

be applied, which stains the aleurone grains, but not the starch; or iodine 
solution, which acts reversely. The large polyhedral endosperm cells, 
which inclose the starch in the whole grain, are almost always entirely 
broken up in the flour. 

Fibro-vascular ducts and pigment masses, pi, appear in the coarser 
meal, but not in the fine flour. 

Meal of Rye, Barley, and Oats. — Figs. 58, 59, and 60 show elements 
of rye, barley, and oats according to Villiers and Collin. 

While, by careful study, there are points of difference observable 



CEREALS, LEGUMES, (VEGETABLES, AND HR'JITS. 



243 



in the tissues of these various ground grains, their close resemblance is 
confusing. The size and characteristic grouping of the starch granules 
furnish by far the most ready means of distinguishing them. 

Barley, even when ground fine, contains more of the seed-coat frag- 
ments and bits of bran than does wheat or rye, and the tissue elements 
are generally larger and better defined. 

Wheat flour, according to Vogl, is readily distinguished from the 
flour of other grains by rubbing the cover-glass back and forth over the 




Fig. 59. — Barley Meal under the Microscope, es, exterior epidermis of the fruit; pa, 
parenchyma of the fruit; h, fibrous hypodermis; ei, interior epidermis of the fruit; 
e', epicarp; d, transverse cells; t, tubular cells; ap, proteid layer; /;, hyaline 
envelope; al, aleurone; pi, masses of pigment; a, starch; jjv, fibro-vascular ducts. 
(After Villiers and Collin.) 

water- mounted sample and observing the thread-like formations of gluten 
characteristic of the wheat. These are stained red with cochineal, are 
not at all apparent in the flour of rye, and hardly at all in that of other 
grains. 

In order to bring out in a striking manner the elements of the various 
flours, Vogl* recommends the following mode of procedure. About 2 
grams of the meal are placed in a dish and stained with an alcoholic 
solution of naphthylene blue. A pinch is removed to a microscope slide 



■ Die wichtigstcn vegetabilischen, Nahrungs u. Genussmitteln, p. 17. 



244 



FOOD INSPECTION AND ANALYSIS. 



and examined in a drop of sassafras oil, or other analogous ethereal oil, or 
guiacol. The elements of the various layers and of the bran fragments 
are clearly distinguished by their bright-blue or blue-violet color, the 




Fig. 6o. — Oatmeal under the Microscope, e, epicarp; p, hairs; b, tegument of the 
grain; ap, proteid layer; t, tubular cells; es, envelope around embryo sheath; 
CO, cotyledons; pi, masses of pigment; a, starch. (After ViUiers and Collin.) 

aleurone and germ tissues are stained pale blue, while the starch cells 
and starch grains remain colorless. 

Corn Meal. — Elements of corn meal are shown in Fig. 6i. 

The transverse cells d and the scutellum, or layer surrounding the 
germ, with its palisade-like envelope, are usually apparent in corn meal. 



BREAD. 

Bread is a term broadly applied to any baked mixture of finely divided 
grain and water, whether or not other ingredients are used. Pilot, or 
ship bread, crackers, and unleavened bread consist almost entirely of 
flour and water with a slight addition of salt. 

Similarly, corn bread or corn cake is frequently made exchisively from 
corn meal and water. In a narrower sense, however, bread is generally 



CEREALS, LEGUMES, VEGETABLES, AND FRUITS. 



245 



understood to mean the raised or leavened product, rendered light and 
porous by the aid of gas, which is generated cither before or during baking. 
Commonly the gas employed is carbon dioxide, generated either by the 
fermentative action of yeast on the sugar of the dough, yielding both 
alcohol and gas, or by the agency of baking chemicals mixed with the 
dough, whereby an alkaline bicarbonate is decomposed by the action 
of an acid to produce the gas. Again, the gas may consist wholly or in 




Fig. 61. — Com Meal under the Microscope, e, epicarp; mc, outer portion of mesocarp; 
mi, inner portion of mesocarp; p, lacunal parenchyma; cl, transverse cells; /, tubu- 
lar cells; sc, scutellum with surrounding envelope; ofi, proteid layer; a, starch, 
both in granules and masses; co, cotyledons. (After \'illicrs and Collin.) 



part of ammonia, yielded by the vaporization during baking of ammo- 
nium carbonate mixed with the dough; and finally, the expansion dur- 
ing baking of the air itself confined in the dough may be the leavening 
agent, as in the case of cake and pastry. 

Wheat flour is of chief value for bread on account of its high content 
of gluten, in which other cereals are lacking. In the preparation of 
ordinary' white bread, the flour is mixed with water or milk, salt, and yeast, 
the materials are mingled thoroughly by kneading and allowed to remain 
for some time in a warm place, during which, by the vinous fermentation 
induced by the yeast, the mass "rises" or forms a light sponge, due to 
the action of the gas on the glutinous dough. 

During the subsequent process of baking, which should take place at 



246 



FOOD INSPECTION AND ANALYSIS. 



a temperature between 230° and 260° C, further expansion ensues, much 
of the water is driven off, and the porous mass sets to form the loaf, the 
outside of which is converted into a brown crust, due to the caramelizing 
of the dextrin and sugar into wh ch the starch of the outer layers is con- 
verted. Among other changes that take place in the interior or "crumb" 
during baking are (i) the partial breaking up of the starch grains, which, 
however, largely retain their identity, though in some degree distorted in 
shape; (2) somewhat obscure changes in the character of the protcids; 
and (3) partial oxidation of the oil or fat. 

The standard for judging the quality of commercial bread may well 
be based on that of the best home -baked family loaf. The well-made 
loaf should possess an agreeable odor, and a sweet, nutty flavor, entirely 
free from mustiness. It should be well "raised," with a good crumbhng 
fracture; it should not be tough or soggy on the one hand (due to under- 
raising), nor extremely dry and spongy on the other (indicative of over- 
raising). Over-raising, moreover, produces sourness, due to advanced 
lactic fermentation. 

Composition of Bread. — The following analyses made in the U. S. 
Bureau of Chemistry of common varieties of bread were summarized 
from Bulletin 13, part 9, averages of a number of analyses being given in 
each case: 



No. of 
Analyses. 



Moisture. 



Proteids, 
NX6.25. 



Proteids, 
NXS-70. 



Ether 
Extract. 



Vienna bread 

Home-made bread . 

Graham bread 

Rye bread 

Miscellaneous bread 
Biscuits or crackers. 
Rolls 



9 

7 

9 

48 



38-71 
33-02 
34.80 

33-42 

34-41 

7-13 

27.98 



8.87 

7-94 
8.03 
8.63 
7.fio 
10.34 
8.20 



8.09 

7.24 



1.06 

1-95 
2.03 
0.66 

T.48 
8.67 
3-41 





Crude 
Fiber. 


Salt. 


Ash. 


Carbohy- 
drates, 

Excluding 
Fiber. 


Calculated 
Calories o£ 
Combus- 
tion. 




0.62 
0.24 

I-I3 
0.62 
0.30 

0-47 
0.60 


°-57 
0.56 
0.69 
1. 00 

0.49 
0.99 
0.69 


1. 19 

1-05' 
1.59 
1.84 
1. 00 
1-57 
1-31 


53-72 
56-75 
53-40 
56.21 
56.18 

73-17 
59.82 


4435 
4467 

4473 
4338 
4429 

4755 
4538 




Graham bread 




Miscellaneous bread 




Rolls 





In the examination of bread for its general quality, without regard to its 
food value, much information may be gained by carefully observing the 



CERE/ILS, LEGUMES, yEGET/IBLES, AND FRUITS. 



247 



physical characteristics of the loaf, its color, taste, odor, porosity, etc. 
In addition to such data, determination of moisture, ash, and acidity 
will usually suffice to enable the analyst to pass judgment on its whole- 
somcness. The following summary gives such analytical data on 
upwards of fifty samples of bread, purchased from cheaper bakeries 
and stores, and examined in the author's laboratory. 

BREAD. 



Kind of Bread. 


No. of 
Analyses. 


Weight of 
Loaf in 
Grams. 


Water, 
Per Cent. 


Per Cent 
Ash in 

Terms of 
SoUds. 


Acidity.* 


White 


44 


653 
126 

430 

500 

367 
420 

' 507 
445 
194 
1291 
55° 
417 
500 

no 


45 • -° 
33 -oo 
40.72 

45.20 
40.10 
41.50 

45 ■ 10 
47.00 
48.20 

47-15 
47.00 

42-30 

48.10 

8.00 


1.83 
0.60 
0.85 

1-55 
0.96 
1.26 
1.20 
2.20 
I -15 
2-13 
2.20 

0-95 
3-5° 
1.94 




Maximum. 


6 2 


Minimum 


1-3 
2.6 


Mean 


Graham 




Maximum 


4-2 




Mean . . - 


3-5 








Muffins .... 


1-7 


Rye 


"Black" 




German with seeds 








*' Knackerbrod*' . 









* Cubic centimeters of tenth-normal soda required to neutralize 10 grams of the fresh bread. 



Water in Bread. — The amount of water is of considerable importance, 
and, in the best bread, varies from ^;^ to 40 per cent. A larger content of 
water than 40% should be considered objectionable in a white bread, 
both on the ground of acting as a make weight, and because a large excess 
of moisture tends to cause the growth of mold. 

Acidity of Bread. — The degree of sourness of a sample of bread is one 
of the most important indications as to its quahty, and is most readily 
obtained by rubbing up in water, by means of a pestle, 10 grams of the 
"crumb," and titrating with tenth-normal alkaU, using phenolphthalcin 
as an indicator. To neutralize the acidity of 10 grams of the normally 
sweet loaf, an average of 2 cc. of the standard alkali solution is required, 
corresponding to 0.72 gram of lactic acid per loaf of an average weight 
of 400 grams. The loaf e.xhibiting the maximum sourness or acidity 
in the above table required 10 cc. of standard alkah per 10 grams of 
bread, corresponding to 11. 61 grams lactic acid in the loaf of 1,291 grams. 



248 FOOD INSPECTION AND ANALYSIS. 

Fat in Bread. — It is well known that the resuhs of fat or ether extract 
as obtained by the ordinary method and expressed in most bread analyses 
are too low, being considerably less than the combined fat of the materials 
entering into its composition. This is probably due to the fact that 
during baking the fat particles are incrusted with insoluble matter, 
which protects them from the subsequent action of the ether. It is further 
claimed by some that the partial oxidation of the fat during baking 
has something to do with the low results. No perfectly satisfactory 
improvement over the regular Soxhlet method for fat extraction in bread 
has been discovered, and therefore this method, as described elsewhere, 
is recommended. 

Adulteration of Bread. — The fraudulent addition of inert foreign 
ingredients to bread is almost never practiced, and is mainly of historic 
interest. Gypsum, chalk, bone ash, and various other minerals have been 
mentioned as possible adulterants, but the amount of any of these 
materials necessar>' to add for purposes of profit could scarcely be present 
without very apparent injury to the quahty of the bread. Their presence 
in any considerable degree would be apparent in the abnormally high 
ash content of the bread. 

The employment of alum to "improve" inferior or unsound flour 
has already been referred to, and, for the same purpose, sulphate of copper 
in small quantities is also said to have been used, enabling the making 
of bread of fairly good appearance from flour that was distinctly damaged. 

Alum in Bread * is tested for by a modification of the logwood process 
described on page 237 as follows: 5 cc. of the logwood tincture and 5 cc. 
of the saturated ammonium carbonate solution are diluted to 100 cc, 
and the freshly prepared mixture poured over about 10 grams of the 
bread crumbs in a porcelain evaporating-dish. After standing a few 
minutes, as much as possible of the liquid is drained off, the bread is 
shghtly washed by one treatment with water, and dried in the water- 
oven. In presence of alum, a dark-blue color is given to the bread, which 
becomes deeper on drying. The color is proportional to the amount 
of alum present. If the sample is free from alum, the color varies from 
red to hght brown. The reagent solution must be freshly prepared. This 
test is not perfectly reliable in the case of very old or sour breads, v/hich 
have been known to give the color test with logwood in the absence of 
alum. 



* Jago on Bread, p. 634. 



CERE/tLS, LEGUMES, yEGETABLES, AND FRUITS. 



249 



Copper Salts in Bread are detected in the ash by the same method 
as that used for canned goods (p. 704). 

Cake and Similar Preparations. — These (h'fTer from bread chiefly by 
the addition of considerable sugar, butter, spices, and other flavoring 
materials. In gingerbread, molasses is used as an important ingredient 
besides ginger. The adulterants of molasses, such as glucose, saLs of 
tin, etc., would thus sometimes occur in gingerbread. In fact stannous 
chlorid has been found in ginger cakes.* 

The following analyses of a few typical varieties of cakes are selected 
from Bulletin 13 of the Bureau of Chemistry: 



Moisture. 



Proteids, 
NX6.25. 



Proteids, 
NX S-70. 



Ether 
Extract. 



Crude 
Fiber. 



Doughnuts . . 
Ginger snaps. 
Fruit cake. . . 
Gingerbread. 
Cup cakes. . . 
Macaroons . . 
Jumbles 



21.61 
4.86 
24.47 
21.49 
14.81 
8.06 
13-34 



6-73 
6.06 

4-56 
6.25 

5-24 
6.67 
7.62 



6.14 

5-53 
4.16 

S-70 
4.78 
6.08 

6-95 



19-33 

15-44 

12-35 

8.42 

15-56 
12.97 

14-79 



0.60 
0.79 

0.90 
0.27 
1. 41 
1.04 



Ash. 



Salt. 



Sugar. 



Carbohy- 
drates 
other than 

Fiber and 
Sugar. 



Calculated 
Calories. 



Doughnuts . . 
Ginger snaps 
Fruit cake. . . 
Gingerbread. 
Cup cakes. . . 
Macaroons . . 
Jumbles 



0.40 
1.82 

1-55 

I-2I 
0.82 
0.97 



0.03 

°-47 

0.28 

0-34 
0.07 

0-39 



1.28 
28.66 

9-48 
32-48 

58-77 
16.60 



50.64 
24.90 

52-46 
30.89 
10. 8g 
46.31 



5529 
4971 

4757 
5073 
4835 
5133 



LEAVENING M.\TERIALS. 

Yeast. — The yeast plant is a fungus of the genus Saccharomyces, 
widely distributed through the vegetable kingdom and in the air. It is 
capable of rapid growth by the muUiplication of its cells when present 
in a favorable medium, such as malt wort, and with propitious condi- 
tions of temperature, moisture, etc. Under such conditions, it forms a 
yellowish, viscous, frothy substance, the chief value of which, in the liquor 
industry, is the production of alcohol, while for bread-making, as a result 
of the same kind of fermentation, the end desired is the leavening of the 
doughy mass by the carbon dioxide liberated. 

* See U. S Dept. of Agric, Bur. of Chem , Bui. 13, p. 1369. 



250 FOOD INSPECTION AND ANALYSIS. 

A vigorous, pure yeast which will "raise" quickly is a great preventive 
against sour bread, for not only is it comparatively free from the germs and 
products of lactic acid fermentation, but by doing its work quickly it 
enables the baker to check the fermentation or raising process before the 
lactic acid or sour decomposition is far advanced. 

Yeast most commonly used in bread-making is of the so-called " com- 
pressed" variety. The use of compressed yeast is almost universal for 
domestic purposes, and is more or less common in bakeries. A small 
amount of brewers' yeast in liquid form from beer wort is used, especially 
in the immediate neighborhood of breweries, and dry yeasts are used to 
some extent in localities so remote that fresh compressed yeast cannot 
readily be obtained. 

Compressed Yeast is a product of distilleries where malt and raw 
grain are fermented for spirits. Most of it comes from whisky wort, and 
some from the worts used in the manufacture of gin and other distilled 
liquors. Little if any of the commercial compressed yeast is made from 
beer wort yeast. 

In the manufacture of compressed yeast, the yeast floating on the top 
of the wort is separated by skimming, while that settling to the bottom 
is removed by running the wort into shallow settling trays. Top yeast 
is considered more desirable than bottom yeast for bread-making. The 
separated yeast is washed in cold water, and impurities are removed, 
either by sieving through silk or wire sieves, or by fractional precipitation 
while washing. The yeast, with or without the addition of starch, is 
finally pressed in bags in hydraulic presses, after which it is cut into cakes, 
packed in tin-foil, and kept in cold storage till distributed for use. 

Such yeast should be used when fresh, as it readily decomposes and 
soon becomes stale. When fresh, it shou'd have a creamy, white color, 
uniform throughout, and should possess a fine, even texture; it should 
be moist without being slimy. It should quickly melt in the mouth 
without an acid taste. Its odor is characteristic, and should be some- 
what suggestive of the apple. It should never be "cheesy," such an 
odor indicating incipient decomposition, as does a dark or streaked color. 

Dry Yeast is prepared by mixing fresh yeast with starch or meal, 
molding into a stiff dough, and drying, either in the sun or at a moderate 
temperature under reduced pressure. Such yeast, when dry, is cut into 
cakes and put in packages. It will keep almost indefinitely. During 
the drying process, many of the yeast cells are rendered torpid and tem- 
porarily inert, and for this reason the dried yeast does not act so promptly 



CEREALS, LEGUMES, VEGETABLES, AND FRUITS. 251 

in leavening as does compressed or brewers' yeast, but when once it begins 
to act it is quite as etlScacious. 

Composition of Yeast. — The following is the result of the analysis 
of under-fermentation yeast, after drying, by Nagele and Loew: 

Cellulose and mucilage 37 

Albuminoids (mycroprotein, etc.) 36 

" soluble in alcohol 9 

Peptones (precipitable by subacetate of lead) ... 2 

Fat S 

Extractive matters (leucin, glycerin, etc.) 4 

Ash 7 



* 



100 



Lintner gives the following average analyses of the ash of three samples 
of yeast, analyzed by him: 

Silica 1.34 

Iron (FejOj) o . 50 

Lime (CaO) 5.47 

Sulphuric anhydride (SO3) 0.56 

Magnesin (MgO) 6.12 

Phosphoric anhydride(P205) 50 .60 

Potash (KjO) and a little soda 33-49 

98.08 

Matthews and Scott give the following as the ash composition of yeast: 

Potassium phosphate 78. 5 

Magnesium phosphate 13.3 

Calcium phosphate 6.8 

Silica, alumina, etc 1.4 

100. o 

Microscopical Examination of Yeast. — Mix a bit of the yeast in water 
on the glass slip till a milky fluid is formed, and stir in a drop of a 
very weak anilin dye solution, such as methyl violet, eosin, or fuch- 



252 FOOD INSPECTION AND ANALYSIS. 

sin.* Put on the cover-glass, and examine under the microscope. 
Living, active cells resist the stain, if the latter is dilute enough, and 
appear colorless or nearly so, while the decayed and lifeless cells are 
stained, and can easily be distinguished by their color. Yeast cells are 
circular or oval in shape, and vary from 0.007 to 0009 mm. in diameter. 
They are sometimes isolated, and sometimes grouped in colonies; each 
cell has an outer, mucilaginous coating or envelope. The interior, granu- 
lar mass or substance of the cell is the protoplasm, and within the 
protoplasm are frequently seen one or more circular empty spaces 
known as vacuoles. 

Yeast cells multiply by the process of budding. The decadence of 
yeast cells is marked by the increased size of vacuole, and by the thicken • 
ing of the cell wall. 




h 

Fio. 62. — Sprouting Yeast-cells [Sacckaromyces cerevisia). [a, after Liirssen; b, after 

Hansen.) 

Yeast-testing. — Available Carbon Dioxide. — The value of yeast in 
bread-making depends on the amount of carbon dioxide which it is capa- 
ble of generating under given circumstances, hence the available carbon 
dioxide is the chief factor in gauging a yeast. There are various methods 
of determination, (i) either by measuring the volume of gas set free by 
the action of a weighed quantity of yeast in a sugar solution of known 
strength, kept for a fixed time at a fixed temperature (say 30°), or (2) 
by conducting the gas from such a fermenting solution through a weighed 
absorption bulb, containing potassium hydroxide and noting the increase 
in weight, or (3) by the more convenient method of Meissl as follows: 

A mixture is made of 400 grams pure, concentrated sugar, 25 grams 
ammonium phosphate, and 25 grams potassium phosphate. A small, 
wide-mouthed flask of about 100 cc. capacity is fitted with a doubly per- 
forated rubber stopper, having two tubes as shown, one of which is bent 
and passes nearly to the bottom of the flask, being fitted at the outer 
end with a rubber tube and glass plug, while the other is connected with 
a small calcium chloride tube. Measure 50 cc. of distilled water into 

* I gram crystallized fuchsin in i6o cc. water having i cc. alcohol. 



CERE/tLS, LEGUMES, VEGETABLES, AND FRUITS. 



253 




this flask, and dissolve 4.5 grams of the above sugar phosj)hate mixture. 
Finally add i gram of the yeast to be tested, stir it well till there are no 
lumps, and cork the flask. Carefully weigh on a 
delicate balance the flask with its contents, and 
immerse in a water-bath at 30° C, keeping it at 
that temperature for six hours. . .\t the end of 
this time, remove the flask from the bath, and 
immediately immerse in cold water to cool the 
contents. Remove the rubber tube with the glass 
plug, and by suction draw out the remaining carbon 
dio.xide. Replace the plug, and having carefully 
wiped olY the flask, again weigh. The loss in 
weight' is due to carbon dioxid set free by the fer- 
mentation of the yeast. ' 

Starch in Compressed Yeast. — The addition of 
potato starch to yeast before pressing has long been 
customary, on the grounds that the starch acted as 
a drier, producing a much cleaner product, and 
one that could be more readily and intimately 
mingled with the materials of the bread, besides 
enhancing the keeping qualities of the yeast, es- 
pecially in warm weather. The best grades of compressed yeast contain 
about 5% of starch, but some are found with 50% and even more. Un- 
doubtedly the larger amounts are added as a make weight. 

The question has frequently been raised whether, with improved 
methods of manufacture, whereby yeast could be produced comparatively 
free from slime, and thus capable of pressure without the admixture of 
starch, the use of the latter should not be considered as an adulterant. 
Some of the compressed yeast on the market is free from starch, and its 
makers claim that this is the only absolutely pure variety, while the presence 
of starch should be distinctly regarded as a violation of the section of the 
food law which forbids the use of a cheaper or inferior ingredient. 

With the marked advantages possessed by a yeast containing starch, it 
is difficult to see why it should be considered as an aduherant, especially 
if present in moderate quantities. Briant claims that the admixture 
of starch up to 5% increases rather than decreases the actual content 
of yeast, in that the starch abstracts moisture from the yeast cells them- 
selves, the proportion of water being much smaller, and that of the yeast 
larger in the starch mi.xed substance. 



Fig. 63. — Apparatus for 
Determining Leaven- 
ing Power of Yeast. 



2 54 FOOD INSPECTION AND ANALYSIS. 

In the absence of a legal standard for starch in yeast, it is difficiJt 
to see how complaints could be maintained under the general food laws 
of most states, without condemning the use of starch altogether. 

Jago suggests 20% as the hmit for starch in yeast, beyond which it 
should be considered as an adulterant. 



CHEMICAL LEAVENING MATERIALS. 

Under this heading are included the various ingredients that enter 
into the mixtures commonly known as "baking powders" which have 
no food value in themselves, but are, strictly speaking, instruments or 
tools that by purely chemical reactions bring about, under certain con- 
ditions, the comparatively quick Hberation of gas and the consequent 
aeration of biscuit, bread, and cake. 

Baking Powders and their Classification. — Formerly the housewife 
was accustomed to measure out in proper proportion a mixture of sour 
milk, or cream of tartar, with saleratus to produce quick aeration of bread. 
The modern baking powder is a natural outgrowth of the former practice, 
and has almost wholly displaced it, producing, as it does, a mixture ready 
for immediate use of an acid and an alkaline constituent in proper pro- 
portion for chemical combination to form the gas. A third ingredient 
is, however, necessary in the commercial powder to check deterioration, 
viz., a dry, inert material, which by absorbing moisture prevents the pre- 
mature chemical action between the reagents. Starch is nearly always 
used for this purpose, though sugar of milk has a Hmited use. The alkaline 
principle of nearly all baking powders is bicarbonate of soda, or saleratus. 
Baking powders are divided naturally into three main classes, with refer- 
ence to the acid principle: 

(i) Tartrate Powders, wherein the acid principle is (a) bitartrate of 
potassium or (6) tartaric acid, typified by the following reactions: • 



188 84 210 44 18 

(a) KHCJi,Oe-}-NaHC03 = KNaC,Hp„-fC02+H20 

Potassium Sodium Potassium Carbon Water 

bitartrate bicarbonate and sodium dioxide 

tartrate 



150 168 230 88 

(J) H2C,HPe+ 2NaHC03 = NaAH,06.2H20+ 2CO2 

Tartaric Sodium Sodium tartrate Carbon 

acid bicarbonate dioxide 



CEREALS, LEGUMES, yEGETABLES, AND FRUITS. 255 

(2) Phosphate Powders, in which calcium acid phosphate is the acid 
principle : 

234 ' 168 136 142 88 36 

CaH,(P0,)2+ 2NaHC03 = CaHPO,+ NaHPO,+ 2CO2+ 2H2O 

Calcium Sodium Calcium Disodium Carbon Water 

acid phos- bicarbonate monohy- phosphate dioxide 

phat^ drogen phos- 

phate 

(3) "Alum Powders," wherein the acidity is due wholly or in part 
to sulphate of aluminum as it occurs in potash or ammonia alum, or in 
the mixed sulphates of aluminum and sodium.* 

Assuming burnt potash alum as the substance used, the reaction 
would be as follows: 

1020 504 156 426 174 264 

KjAl^i 504),+ 6NaHC03 =Alj(OH)e-f 3Na2SO,+ K,SO,+ 600^ 

Burnt pot- Sodium Aluminum Sodium Potassium Carbon 

ash alum bicarbonate hydrate sulphate sulphate dioxide 

Natural y many baking powders of complex composition are met 
with, embodying various mixtures of the above classes. 

Composition of Various Baking Powders. — Following are analyses 
of typical baking powders of the above classes: f 

I. Cre ni of Tartar Baking Powder: 

Total carbon dioxide, COj 13 ■ 21 

Sodium oxide, Na^O 13-58 

Potassium oxide, KjO 14-93 

Calcium oxide, CaO .18 

Tartaric acid, C^HjOj 41 .60 

Sulphuri acid, SO .10 

Starch 7.42 

Water of combination and association by difference. . . 8 . 98 



100.00 



Available carbon dioxide 12.58%. 



* It is probable that very little ammonia or potash alum is actually used at present in 
this class of powders. A product largely used is known in the trade as C. T. S. (cream of 
tartar substitute) and is a calcined double sulphate of aluminum and sodium. 

|Div of Chem.. Bui. 13, part 5, pp. 600, 604. and 606. 



256 FOOD INSPECTION AND ANALYSIS. 

2. Phosphate Baking Powder: 

Total carbon dioxide, CO2 13 -47 

Sodium oxide, Na^O 1 2 . 66 

Potassium oxide, KjO .31 

Calcium oxide, CaO 10 . 27 

Phosphoric acid, P2O5 2 1 . 83 

Starch 26.41 

Water of combination and association by difference. .. 15-05 

100.00 
Available carbon dioxide 12.86%. 

3. Alum Baking Powder: 

Total carbon dioxide, COj 9-45 

Sodium oxide, NajO 9.52 

Aluminum oxide, AI2O3 3-73 

Ammonia, NH3 1.07 

Sulphuric acid, SO3 10.71 

Starch 43-25 

Water of combination and association by difference . . 22.27 



100.00 
Available carbon dioxide 8.10%. 

Mixed Powders: 

Total carbon dioxide, CO2 10.68 



Sodium oxide, Na^O 14 

Calcium oxide, CaO i 

Aluminum oxide, AUOj 4 

Ammonia, NH3 i 

Phosphoric acid, P2O5 3 

Sulphuric acid, SO3 11 

Starch 42 

Water of combination and association by difference . . 10 



04 
29 

59 
13 
38 
57 
93 
39 



100.00 
Available carbon dioxide 10.37%. 

The Adulteration of Baking Powder. — No substance that comes 
within the domain of food inspection is the subject of so much controversy 



CEREALS, LEGUMES, l^EGET/IBLES, AND FRUITS. 257 

as baking powder. Unless a specific law forbids the use of a particular 
ingredient or class of ingredients, or in some manner regulates the 
labelling of the package, no baking powder of any kind can be considered 
adulterated under the general food law, imless it can be proved lo be 
injurious to health, or unless it contain inert and useless mineral matter. 

As a matter of fact, the residue left in the bread by all classes of baking 
powder consists of one or more drugs recognized in the Pharmacopoeia, 
all of which in large quantity exercise well-marked toxic effects on the 
human system. Artificial digestion experiments, and physiological tests 
on the lower animals, using excessive doses of any of the above drugs, do 
not show the effect of the ever}'-day use of baking powder in bread on the 
human system, and only a systematic examination of the effect of such 
use on large numbers of people can prove conclusively whether or not any 
one class of baking powders is harmful, and hence whether or not it 
should be classed as adulterated. Aside from the question of the harm- 
fulness of the acid ingredients employed in baking powder, which is the 
subject of much controversy among rival manufacturers, there can be 
no doubt that such inert make weight substances as calcium sulphate, 
or terra alba, or clay, which are entirely useless, and lower the strength, 
quality, and purity of the powder, are to be considered in the light of adul- 
terants. 

Cream of Tartar — 7/5 Nature and Adulteration. — Cream of tartar, 
or potassium bitartrate (KH5C408), is the purified product obtained by 
the recrystallization of the crude argols or lees deposited in the interior 
of wine casks. 

The lees, or argols, consist chiefly of crude potassium bitartrate, which 
is present in the juice of the grape, but is insoluble in the alcohol formed 
in the fermentation, and is hence deposited. If, for the clarification of 
the wine, such substances as gypsum or plaster of Paris are used, tar- 
trate of calcium will be found mixed with the bitartrate of potassium in 
the lees. Hence it is that calcium tartrate is sometimes found in commer- 
cial cream of tartar. 

Potassium bitartrate is insoluble in alcohol, sparingly soluble in cold, 
and readily soluble in hot water. 

Allen * states that when the calcium tartrate is present in excess of 10%, 
it should undoubtedly be considered as an adulterant. 

Other common adulterants of cream of tartar are calcium acid phos- 
phate, gypsum, or plaster of Paris, starch, and alum. 

* Analyst, V, 114. 



258 FOOD INSPECTION AND ANALYSIS. 

Chemical Analysis of Baking Chemicals. — The degree of purity of 
cream of tartar is best determined by weighing out 0.188 gram of the 
sample, dissolving in hot water, and titrating with tenth-normal sodium 
hydroxide, using phenolphthalein as an indicator. If the article is pure, 
exactly 10 cc. of tlie standard alkali will be required for the titration. All 
the above-named adulterants, with the exception of alum, are either insol- 
uble, or sparingly soluble in hot water, and will indicate the impurity of 
the sample even before titration. If the adulterant be alum, the sample 
would go into solution in the water, but the alum would be precipitated 
by the sodium hydroxide, the precipitate being, however, soluble in an 
excess of the alkali. 

Sodium Bicarbonate on account of its cheapness is rarely adulterated, 
save by the occasional presence of common salt, an impurity incidental 
to its manufacture. The degree of purity of sodium bicarbonate is best 
ascertained by titration with standard acid, each cubic centimeter of tenth- 
normal acid being equivalent to 0.0084 gram of sodium bicarbonate. 

DETERMINATION OF TOTAL CARBON DIOXIDE. 

Reagents. — Calcium Chloride. — ^This can be obtained in granulated 
form in pellets of about the size of peas, specially prepared for moisture 
absorption. 

Soda Lime.* — ^To a kilogram of commercial sodium hydroxide, 500 
to 600 cc. of water are added, and the mixture heated in an iron kettle 
to form a thin paste. While still hot, a kilogram of coarsely powdered quick- 
lime is added, stirring with an iron rod. The lime s slaked, and the whole 
mass heats and steams up. No outside heat is necessary at this stage, 
but the mass is stirred and the lumps broken up. As soon as cool, place 
the product in wide-mouthed bottles, and seal with paraffin wax. The 
product should be slightly moist to give the best results. 

Hydrochloric 4 ci(f.— Specific gravity i.i. 

Sulphuric Acid. — Specific gravity 1.85. 

Potassium Hydroxide Solution. — Specific gravity 1.55. 

Two varieties of apparatus are in use for the determination of carbon 
dioxide. In one form the amount of carbon dioxide is obtained by dif- 
ference in weight of the apparatus, before and after elimination of the 
gas. In the other, the gas driven out of a given weight of the sample is 
absorbed, and its amount calculated from the increase in weight of the 

'* Benedict and Town, Jour. Am. Chem. Soc, Vol. XXI, p. 396. 



CEREALS, LEGUMES, VEGETABLES. AND FRUITS. 



259 



absorbent. Types of these varieties are the Geissler and the Knorr 
apparatus 

The Geissler Apparatus. — This consists of a flask A, having a ground 
neclc a, and a flaring funnel-top A'. B is an elongated bulb, closed at the 
top by the hollow stopper K, and terminating below in the hollow stem 
B' , which is accurately ground at b to fit the neck a. Fused into the 
bulb B is the tube C, and within this is the small tube D, open at the top 
and communicating directly with the hollow stem 
B'. gg are openings between B and C. 

£ is a fine glass tube, passing from the bottom 
of the hollow stem B' and to the height of a small 
protuberance e in the bottom of the funnel A', the 
construction being such that by turning the bulb 
and stem BB' in the neck a of the flask A the 
tube E may be opened or closed at the top. H 
is a side tube in the flask A, closed by the ground 
stopper h. 

■ The bulb B and the tube C are filled with 
strong sulphuric acid nearly to the top of the tube 
D, by passing through the neck at the top, which 
is then closed by the stopper K. 

About 0.5 gram of the dried sodium bicar- 
bonate, or I gram of the baking powder, is in- 
troduced into the flask A through the neck a 
from a weigh ng-tube or otherwise, so that its 
exact weight is known. The stem B' is then 
inserted, and the funnel-top A' is nearly filled 
with the hydrochloric add, the tube e being fig. 64.-Geissler's CO, Ap. 

closed. paratus or Alkalimeter. 

The entire apparatus is then weighed, after which the stem is turned 
to bring the protuberance e nearly opposite the tube E, uncovering it 
enough to allow the acid to pass slowly down the tube into the flask and 
upon the powder in the bottom of the flask. The carbon dioxide evolved 
passes through the opening / into the hollow stem B', thence up through 
the tube D, and down and up (as indicated by the arrows) through the sul- 
phuric acid, which absorbs the moisture. Finally the gas passes out 
through the tube K. 

After the evolution of the gas has continued for two or three minutes, 
gentle heat is applied to the flask from a gas flame, and the solution is 




26o 



FOOD INSPECTION AND ANALYSIS. 



brought to boiling, which is continued for a few minutes, during the latter 
portion of which the stopper h is removed, and the tubulure connected 
by rubber tubing with a system of two U tubes, one containing soda 
iime, and the other calcium chloride. The tube k is then connected with 
the aspirator and a current of dried air is passed through the apparatus at 
the rate of about two bubbles per second, long enough to displace all 
the carbon dioxide. The rubber tubes are then disconnected, the stopper 
K is replaced, and the apparatus cooled to room temperature and weighed. 

The available carbon dioxide in baking powder is determined in the 
same manner as above, by simply substituting freshly boiled, distilled 
water for the hydrochloric acid in the funnel-top A'. 

The Knorr Apparatus [Modified). — The apparatus (Fig. 65) consists 
of (i) a flask, into which is introduced an accurately weighed amount of 




Fig. 65. — Modified Knorr Apparatus for Determining Carbon Dioxide. 



the dry samp'e (0.5 to i gram of sodium bicarbonate or i to 2 grams of 
baking powder); (2) a funnel, the tube of which, provided with a stop- 
cock enters the stopper of the flask; (3) a soda lime tube, entering a 
stopper at the top of the funnel; (4) a Liebig condenser, connecting with 
a tuba passing through the stopper of the flask; (5) a Geissler bulb, filled 
with the sulphuric acid; (6) a potash absorption-bulb, and (7) a calcium 



CEREALS, LEGUMES, yEGET/IBLES, ANL') FRUITS. 261 

chloride tube, which may if desired be replaced by a second sulphuric 
acid bulb. The potash absorption apparatus s accurately weighed 
before being connected up, and the funnel is nearly filled with the hy- 
drochloric acid reagent, after which the soda lime tube is attached. The 
calcium chloride tube is connected by a rubber tube with the aspirator, 
and a current of cold water is allowed to run through the outer Liebig 
condenser-tube. 

The stop-cock in the funnel-tube is first opened to allow the acid 
to slowly run into the flask, the flow being regulated to insure slow evolu- 
tion of the gas. 

The aspirator is then turned on so that about two bubbles of air per 
second pass through the apparatus, and gentle heat is applied to the 
flask by the gas flame, the solution within being brought to boiling, and 
the boiling continued for several minutes after the vapor has begun to 
gather in the condenser. 

Prolonged boiling of the solution should be avoided, and in a series of 
tests the time of boiling should be precisely the same in all cases. 

After removing the flame, the flask is allowed to cool, the aspiration 
being continued. The absorption-tube is then removed and weighed 
at room temperature, the increase in weight being due to the carbon 
dio.xide. 

The Available Carbonic Acid in Baking Powder is determined in the 
same manner as the total carbon dioxide, except that recently boiled, 
distilled water is substituted for the hydrochloric acid. 

TARTARIC ACID. 

Detection.* — It is frequently desirable to test a so-called " compound" 
cream of tartar, or a "cream of tartar substitute," or an adulterated sample 
made up largely of foreign ingredients, to see if any tartaric acid, free or 
combined, be present. The following test is applicable in presence of 
phosphates: 

If the substance to be tested is found to be free from starch, mix a 
little of the dry powder in a test-tube with a bit of dry resorcin, add a 
few drops of concentrated sulphuric acid, and heat slowly. A rose-red color 
indicates tartaric acid or a tartrate, the color being discharged on dilution 
with water. 

In case of baking powder, or a cream of tartar substitute containing 

* Wolff, Rev. Chim. Analyt. et appi. 4 (iSgg), p. 2631. 



262 FOOD INSPECTION AND ANALYSIS. 

starch, shake repeatedly from 3 to 5 grams of the sample with about 250 
cc. of cold water in a large flask, allowing the insoluble portion to subside. 
Decant the solution through a filter, and evaporate the filtrate to dryness, 
after which test the dried residue or a portion thereo with resorcin and 
sulphuric acid as above described. 

Determination of Total Tartaric Acid. — Modified Heidenhain 
Method* — Applicable only in the absence of phosphates and salts of 
aluminum and calcium. 

Into a shallow porcelain dish, 6 inches in diameter, weigh out 2 grams 
of the material and sufficient potassium carbonate to combine with all 
tartaric acid not in the form of potassium bitartrate. Mix thoroughly 
with 15 cc. of cold water, and add 5 cc. of 99% acetic acid. Stir for half 
a minute with a glass rod bent near the end. Add 100 cc. of 05% alcohol, 
stir violently for five minutes, and allow to settle at least thirty minutes. 
Filter on a Gooch crucible with a thin layer of paper pulp, and wash 
with 95% alcohol until 2 cc. of the filtrate do not change the color of 
htmus tincture diluted with water. Place the precipitate in a small cas- 
serole, dissolve in 50 cc. of hot water, and add standard fifth-normal potas- 
sium hydroxide solution, leaving it still strongly acid. Boil for one minute. 
Finish the titration, using phenolphthalein as indicator, and correct the 
reading by adding 0.2 cc. One cc. of fifth-normal potassium hydroxide 
solution is equivalent to 0.026406 gram tartaric anhydride (C^H^OJ, 
0.03001 gram tartaric acid (HsC^H^Oo), and 0.03763 gram potassium 
bitartrate (KHC.HPe)- 

The standard of the potassium hydroxide solution should be fixed by 
pure dry potassium bitartrate. 

The accuracy of this method is indicated by the agreement of the 
percentages of potassium bitartrate in cream of tartar powders containing 
no free tartaric acid, obtained by calculation from the tartaric acid, with 
those obtained by calculation from the potassium oxide. 

In presence of phosphates or of aluminum and calcium salts, the only 
satisfactory method of arriving at the amount of tartaric acid present is 
by difference, having determined or calculated the other ingredients. 

DETERMINATION OF STARCH. — McGill's Method t (Modified). — Digest 
I gram of the sample with 150 cc. of a cold 3% solution of hydrochloric 
acid during iwenty-four hours, with occasional shaking. Filter through 



* Provisional m^jthod of the A. O. A. C, Bur. of Chem., BuL 65, p. 104. 
t Canada Inland Rev. Bui. 68, p. 33. 



CERE/4LS, LEGUMES, yEGET^BLES, AND FRUITS. 263 

a tared Gooch crucible, wash first with water until neutral, then once 
with alcohol, and finally with ether. Dry at 110° C. for four hours, cool, 
and weigh. Burn off the starch, and again weigh. The dilTerence in 
the two weights indicates the weight of the starch. The purity of the 
starch is insured by examination with the microscope. 

Acid Conversion Method.* — If the sample contains lime, mix 5 grams 
in a 500-cc. flask with 200 cc. of 3% hydrochloric acid, and let the mixture 
stand an hour with frequent shaking. Filter through a wetted ii-cm. 
filter, wash with water, and transfer the starch by a wash-bottle from the 
filter-paper back into the original flask, using 200 cc. of water. 

If the sample be free from lime, weigh 5 grams directly into the 500-cc. 
flask with 200 cc. of water. In either case add 20 cc. of hydrochloric 
acid (specific gravity 1.125) and heat the flask in boiling water for 2| 
hours, the fla k being provided with a reflux condenser. Determine the 
dextrose, and from this the starch in the regular manner. 

Aluminum Salts. — Detection.f — (a) In Baking Powder. — Appli- 
cable in presence of phosphates. Burn to an ash about 2 grams of the 
sample in a platinum dish. Extract with boiling water and filter. Add 
to the filtrate sufficient ammonium chloride solution to produce a distinct 
odor of ammonia. A flocculent precipitate indicates aluminum. 

In igniting, as above directed, sodium aluminate results from the 
more or less complete fusion. The reaction which occurs may be repre- 
sented as follows: 

Na^AljO.-f 2NH,Cl-f4H20 = Al2(0H)„+ 2NH,0H-f 2NaCl. 

Sodium Ammonium Aluminiun Ammonia Salt 

aluminate chloride hydroxide 

If any phosphate of lime be present, it will be insoluble in the solution 
of the ash. If phosphate of sodium or potassium be present, it will go 
into solution, but will only precipitate out when an aluminum salt is also 
present on the addition of the ammonium chloride reagent. 

{b) In Cream of Tartar. — Mix about i gram of the sample with an 
equal quantity of sodium carbonate, bum to an ash, and proceed as in 
the case of baking powder (a). 

Determination of Alumina. — The above qualitative method with am- 
monium chloride may be made quantitative in presence of phosphates 
as follows: After carrying out the qualitative method as above directed, 
filter off the final precipitate, dissolve it in nitric acid, and test it for phos- 

* U. S. Dcpt. of Agric, Bur. of Chem., Bui. 65, p. 105. 

t Leach, 31st An. Rep. Mass. State Board of Health, 1899, p. 638. 



:64 FOOD INSPECTION AND ANALYSIS. 

phate with ammonium molybdate. If phosphates are found absent, 
proceed as before with a weighed amount of the sample and wash, ignite, 
and weigh the residue as AljOj. 

If phosphate is found present in the ammonium chloride precipitate, 
proceed as before, igniting and weighing the total residue. Then deter- 
mine the P2O5 in the latter and subtract from the total. The difference 
will be the AUO3. 

Determination of Lime. — 5 grams of the sample are treated in a 500- 
cc. gi'aduated flasli with 50 cc. of water and 25 cc. of concentrated hydro- 
chloric acid. Add water to the mark, shake, and allow the starch to settle. 
Decant through a dry filter, and to 50 cc. of the filtrate add ammonia 
nearly to neutralization, and acidify with acetic acid. Then add ammo- 
nium acetate and boil. Filter, if necessary, and precipitate the lime with 
an excess of ammonium oxalate. Filter, wash, and ignite over a blast- 
lamp. Weigh as CaO. 

Determination of Potash and Soda.* — Weigh out 5 grams into a 
platinum dish, and incinerate in a muffle at a low heat. The charred 
mass is well rubbed up in a mortar, then boiled fifteen minutes with 
about 200 cc. of water to which has been added a little hydrochloric 
q.cid. The whole is transferred to a 500-cc. flask, and, after cooling, 
made up to the mark and filtered. Of the filtered liquid 100 cc, 
representing i gram of the sample, are measured out, heated on the 
water-bath, and a slight excess of barium chloride added; then with- 
out filtering barium hydroxide is added in slight excess, the precipitate 
filtered oil, and washed. To the filtrate is added a httle ammonium 
hydroxide, and then ammonium carbonate until all the barium is pre- 
cipitated. This precipitate is fiUered and washed, the filtrate evapo- 
rated to dryness, and carefully ignited until all volatile matter is driven 
off, when it is weighed. This gives the weight of the mixed chlorides. 
The residue is taken up with hot water, from 5 to 10 cc. of a 10% 
solution of platinic chloride added, and the whole evaporated to a sirupy 
consistency on the water-bath; it is then treated with strong alcohol, the 
precipitate washed with alcohol by decantation, transferred to a Gooch 
crucible, dried at 100° C, and weighed. The weight of the precipitate 
multiplied by 0.19308 gives the weight of K2O, and by 0.3056 the equiv- 
alent amount of KCl. The weight of KCl found is subtracted from the 
weight of the mixed chloride, the remainder being NaCl, which multiplied 
by 0.5300 gives the weight of Na20 in the sample. 

* U. S. Dept. of Agric, Div. of Chem., Bui. 13, part 5, p. 593. 



CEREALS, LEGUMES. yEGETABLES. AND FRUITS 265 

Determination of Phosphoric Acid. — Method oj the A. O. A. C* — 

Mix 5 grams of the material with 10 cc. of magnesium nitrate solution,! 
dr>', ignite, and dissolve in hydrochloric acid. Take an aliquot part of 
the solution prepared above, corresponding to 0.25 gram, 0.50 gram, or 
I gram, neutralize with ammonia, and clear with a few drops of nitric 
acid. In case hydrochloric or sulphuric acid has been used as solvent, 
add about 15 grams of dry ammonium nitrate, or a solution containing that 
amount. To the hot solution add 50 cc. of molybdic solationj for every 
decigram of PoOj that is present. Digest at about 65° for an hour, filter, 
and wash with cold water, or preferably ammonium nitrate solution. § 
Test the filtrate for phosphoric acid by renewed digestion and addition 
of more molybdic solution. Dissolve the precipitate on the filter with 
ammonia and hot water and wash into a beaker to a bulk of not more 
than 100 cc. Nearly neutralize with hydrochloric acid, cool, and add 
magnesia mixture from a burette; add slowly (about i drop per second), 
stirring vigorously. After fifteen minutes add 30 cc. of ammonia solution 
of density 0.96. Let stand for some time; two hours is usually enough. 
Filter, wash with 2.5% NH3 until practically free from chlorides, ignite 
to whiteness or to a grayish white, and weigh. 

Determination of Sulphuric Acid. — Provisional Method A. O. A. C.\\ — 
Boil 5 grams of the powder gently for one and one-half hours with a mix- 
ture of 300 cc. of water and 15 cc. of concentrated hydrochloric ac d. 
Dilute to 500 cc, draw off an aliquot portion of 100 cc, dilute considerably, 
precipitate with barium chloride, fiher through a Gooch crucible, ignite, 
and weigh. Direct solution of the material without burning the organic 
matter was proposed by Crampton.lf The dextrose, formed by the action 
of the acid on the starch of baking-powders, does not interfere with the 
accuracy of the process. 

Determination of Ammonia (present in the form of ammonia alum 
or ammonium carbonate). Mix 5 grams of the sample with 200 cc. of 
water, and add an excess of sodium hydroxide. Distill into standard 
acid, and determine the ammonia by titration. 

* U. S. Dept. of Agric, Div. of Chem., Bui. 46, p. 12. 

t Prepared as follows: Dissolve 80 grams calcined magnesia in nitric acid, avoiding an 
excess of acid, then add a little calcined magnesia in excess, boil, filter from the excess of 
magnesia, ferric oxide, etc., and dilute with water to 500 cc. 

I Reagent No. 53. 

§ Prepared by dissolving 100 grams of ammonium nitrate, Reagent No. 54, in i liter of 
water. 

II U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 107. 

H U. S. Dept. of .^gric, Div. of Chem., Bui. 13, part 5, p. 596. 



266 



FOOD INSPECTION AND ANALYSIS. 



SEMOLINA, MACARONI, AND EDIBLE PASTES. 

Semolina is the coarse meal ground from certain varieties of hard 
or "durum" wheats, grown originally in Italy, Sicily, and Russia, but 
at present in France and certain parts of the United States and Canada. 
This hard wheat is high in gluten, and especially adapted for the prepara- 
tion of macaroni and the various pastes. A peculiar process is employed 
in preparing the wheat, whereby the husk is removed by wetting, heating, 
grinding, and sifting, the resulting meal or semolina, being in the form 
of small, round, glazed granules. 

The semolina thus prepared furnishes the basis of the Italian edible 
pastes, being mixed with warm water, kneaded, and molded into various 
forms and finally dried, either by pressure through holes in an iron plate, 
or otherwise. 

Macaroni is the larger of the slender- tube or pipe-shaped products; 
vermicelli is the worm-shaped variety, produced when the holes in the 
plate are very small; spaghetti and noodles are terms applied to cord- 
like pastes intermediate in size between the others. A variety of Italian 
pastes or pdtes are made by rolling the kneaded semolina into thin sheets , 
and cutting out in shapes of animals, letters of the alphabet, etc. 

The composition of some of these products is as follows: 



No. of TIT . „ 

Samples.! 



Protein. 



Fat. 



Total 
Carbohy- 
drates. 



Crude 
Fiber. 



Ash. 



Fuel 
Value 

per 
Pound. 
Cals. 



Semolina* 1 10-5° 11.96 

Macaroni t ' n io-3 : i3-4 

Noodles t i 2 10.7 1 1. 7 

Spaghettif 3 10-6 12. i 

Vermicellit 15 n-o io-9 



0-60 
0.9 
i.o 
0.4 



75-79 

74-1 

75-6 

76-3 

72.0 



0.50 



0.4 
0.4 



0.65 

1-3 
1.0 
0.6 
4-1 



1665 
1665 
1660 
1625 



■Balland. 



t Atwater and Bryant. 



Nearly all these foods are free from adulteration, though not all are 
made from the most suitable wheat. Eggs are sometimes used in the 
preparation of noodles, being kneaded into the paste before drying. 
Noodles are frequently colored yellow either with turmeric or with coal- 
tar dyes. Rice, corn, and potato flours have been used in the preparation 
of the cheaper varieties of semolina, but rarely in this country. In parts 
of Italy juices of carrots, onions, and other vegetables are said to be 
mingled with the paste, but for local consumption only. 

Shredded Wheat is a whole-wheat preparation, put out in the form 
of light biscuits built up of fine porous threads, not unlike those of vermi- 



CEREALS, LEGUMES, VEGETABLES, AND FRUITS. 



267 



celli. The wheat, softened by boiling, is shredded by passing through 
a peculiar machine, after which the biscuits are made by lightly putting 
together the threads and by final baking. The comparative composition 
of shredded wheat and of typical whole wheat is thus shown by Wiley:* 



Constituents. 


Shredded 
Biscuit. 
Per Cent. 


Typical 
Wheat. 
Per Cent. 




IO-57 
12.06 

1-03 

2.65 

2.58 

71. II 


10.60 
12.25 

•■75 
1-75 
2.40 

71-25 




Ether extract 


Ash 


Crurle fiber. , . . 







PREPARED CEREAL BREAKFAST FOODS. 

The large number and variety of these preparations now on the market 
testify to the fact that the breakfast cereal forms a most important, as well 
as considerable, portion of our food supply. These foods are generally 
prepared from wheat, oats, and corn, and are, as a rule, remarkably pure 
and free from adulteration, though the food value of different varieties 
is often grossly misstated by their manufacturers. Formerly the break- 
fast food consisted entirely of the coarsely ground, generally decorticated, 
raw cereal grain, and required a long period of cooking to prepare it for 
use. At present many of the oat products, and to some extent also those 
of com, rice, and wheat, are subjected to a more or less preliminary cook- 
ing and drying, whereby they are capable of being prepared for use in 
a much shorter time, and their keeping qualities are enhanced. The 
so-called rolled oats are prepared by softening the grains through steam- 
ing, after which they are crushed between rollers and afterwards dried. 
The steaming process is a typical one for various other cereals, though 
in some cases the heating consists in baking or kiln drying. 

The effect of the preliminary cooking on the finished product varies 
somewhat according to whether dr)' or moist heat has been apphed, and 
is chiefly noticeable in the altered character of the carbohydrates. In 
aU cases the starch is rendered more soluble, whether by the conversion of 
a portion into de.xtrin and de.xtrose, or by a simple breaking down 
of the starch grains, as in the case of bread in baking. 

In spite of the seemingly endless variety of the package cereals, they 

* U. S. Dept. of Agfic, Bur. of Chem., Bui. 13, p. 1337. 



268 



FOOD INSPECTION AND ANALYSIS. 



divide themselves as a matter of fact into a very few well-defined classes, 
the members of which differ but httle from each other except in name. 

First there are the raw cereal grains of the oat, wheat, and corn, pre- 
pared by simple crushing to various degrees of fineness, after decorticating; 
next comes the classes of partially cooked preparations of each of these 
grains, appearing in various forms of " flai^es," "granules," "grits," 
etc., and again a class known as malted cereals, in which the moist, ground 
grain is mixed with malted barley, and, by controlling the temperature, 
a portion of the starch is converted to maltose and dextrin, after which 
the mixture is crushed between hot rollers and dried. 

In the preparation of most of the com breakfast products, such as 
samp and hominy, it is customary' to remove the germ, which contains 
the oil and fat, lest the tendency of the latter to become rancid should 
resuh in the deterioration of the food. In wheat foods the germ is less 
often removed, and rarely, if ever, in oat preparations. The amount 
of fat found in the prepared cereal food as compared with that in the 
whole grain is of interest in this connection. 

Composition of Some of the Common Breakfast Cereals. — The follow- 
ing analyses will serve to typify the various classes of these preparations 
as they appear on the market: 



Wheat* 

Wheatena 

Petti] ohn's breakfast food.. . 

Farina 

Cracked wheat 

Ralston's breakfast food. . .. 

Fould's wheat germ 

Oats.* 

Quaker 

Hornby's 

Buckeye 

Corn. 

Cerealine * 

Velvet meal * 

Hecker's hominy t 

Nichols' snow-white sampf. . 
M I SCELLAN FOUS.f 

Brittle bits 

Force 

Grape-nuts 

Ralston's health barley food. 



6.65 

9-51 
10.94 

9.30 

9-V 

10.13 

7.40 
7-63 
7-54 

9-55 
9.80 
II 



Carbohydrates. 



10.8 



2.28 14.17 

1-45 10 56 
1.56 10.90 

2.22|I2.6o 
1.90 15.10 

I.46I13.3O 

6.08 17.20 

7-35 17-82 
8.3016.89 



1.24 
2.32 
0-3 
0-3 

°-S 
1-4 
I.I 
i.o 



9.90 

6.75 
9.4 



14. 1 
II. 6 
12.6 
10.7 



75-62 
76.96 

75-91 
94.42 

71-75 
73-93 

66.65 
65-47 
65-55 

78-75 
80-^3 
78.6 
80.5 

76.0 
76.8 
78.4 
75-8 



•IS 



3-9 
2.8 
3-2 
3-3 
4-6 

3-7 



-2^ 



70.50 

72.15 
72.12 
69.63 
65.60 
69-35 



1.6 64.65 
1.3 62.74 
3.3 60.90 



7-1 



70-93 
77-77 



3-,- 



I. 

2.01 

0-59 

1-49 
1-55 



1.28 
1.52 
0.69 
1 .46 

1-53 
I.I 



113 



I 



1.40 1.67 



1-43 
1-35 

0.72 
0.96 
0.4 
0.4 

1.0 
2.0 
1.9 
0.6 



1-73 
1-72 

0.56 
0.60 
0.2 
0-3 

1-5 
2.8 



363 
231 
°-i53 
0-333 
°-343 
0.326 

-34: 
-443 
0.416 

192 
0.185 



4343 
4174 
4051 
4236 
4158 
4087 

4673 
4756 
4526 

4542 
3660 



* Analy-;es niade by Slosson, WyominR Exp. Sta.. Bui. $3. 

t Analyses made by Merrill and Mansfield, Maine Exp. Sta., Bui. 84. 



CERE/ILS, LEGUMES, yEGETABLES, AND FRUITS. 269 

The methods of analysis employed for these preparations are the 
same as for ordinary cereals (p. 217), the sample being ground hne 
enough to pass tlirough a i-mm. sieve. 

Prepared Foods for Infants and Invalids. — In dealing with the com- 
position and analysis of this class of proprietary foods more than ordinar}' 
care is necessary, in view of the fact that one or another of these prepara- 
tions are frequently prescribed for the exclusive diet of those whose very 
life may depend on the character and suitability of the food to the case 
in hand. Many of these foods do, as a matter of fact, honestly fulfill the 
claims of their manufacturers, but others fall far short of so doing, so 
that it is hardly safe to use them unless some intelligent idea of their 
composition can be gained. It is not, as a rule, within the province of 
the analyst to furnish an opinion regarding the adaptability of a certain 
food to the requirements of an infant or invalid, but rather to provide 
the necessary data whereon such an opinion may be intelligently based. 

A simple statement of moisture, fat, protein, carbohydrates (by dif- 
ference), and ash, which in the case of ordinary foods would often be 
sufficient, would be obviously inadequate in expressing the analysis of 
an infant food, since it is of much more vital importance than in other 
foods to know the solubility of the food itself, and, to as great an extent 
as possible, the character of the carbohydrates. 

The chief ingredients of many of these preparations are wheat, or 
mixed cereals high in starch. Many of the foods are, according to the 
directions, to be used practically without cooking, but by simply mixing 
with milk or water, and, in some cases, bringing to the boiling-point. 
Hence the degree of conversion which the raw starch has undergone in 
the process of manufacture of the food should, if possible, be ascertained 
as a prime factor in judging of its character and adaptability to the needs 
of the young child and of the sick. Incidentally it should be said that 
few if any of the infant foods, even those whose high character has long 
been established by continued trial, conform very closely to the composi- 
tion of woman's milk, which was long accepted as the true standard on 
which to base their efficiency. Hence it is no easy task to pass judgment 
on a particular food from its chemical composition alone without trial, 
nor is it right to unqualifiedly condemn in all cases food high in insoluble 
carbohydrates, since there are undoubtedly many instances in which 
such foods are successfully used. 

Classification and Preparation of Infants' Foods, — These foods may 
for convenience be divided into two main classes, viz., farinaceous foods, 



2 7° FOOD INSPECTION AND ANALYSIS. 

or those which are prepared wholly or chiefly from one or more cereal 
grains, and lactaled joods, or those in which cow's milk forms the basis, 
but which may contain in addition thereto various other substances, such 
as cereals, sugars, etc. 

The farinaceous foods, which are usually directed to be mixed with 
milk before using, may be further subdivided into (a) those that consist 
chiefly of unconverted starch, (h) those whose starch has been nearly 
all hydrolyzed to soluble form in the process of manufacture, and (c) those 
which contain much unconverted starch, but in addition thereto diastase 
or some other ferment, which, when the food is mixed with warm water 
or milk, is supposed to convert all the starch to soluble form. 

The unconverted starch foods are nearly all made up of baked dry 
flour, chiefly that of wheat, but sometimes a mixture of cereals (as oats, 
barley, and wheat) and sometimes oats or barley alone. The baking 
breaks down to some extent the starch grains, as in the case of bread 
or crackers, but does not actually convert much of it to sugar. 

The soluble farinaceous foods are usually prepared somewhat as 
follows: A mixture of ground wheat and barley malt (with sometimes a 
little wheat bran) is mixed with water to form a paste, and a little bicar- 
bonate of potash added. The mixture is heated at 65° C. for sufficient 
time to convert the starch, after which it is exhausted with warm water, 
the extract being strained, and the filtrate evaporated to dryness to form 
the food. The sugars of such foods consist largely of maltose mixed 
with dextrin. 

The farinaceous foods, which depend for the conversion of their starch 
on the method of cooking or heating before serving, arc usually mixtures 
of wheat or other cereal flour with malt or pancreatic extract. 

The milk foods are variously prepared, either by the simple desicca- 
tion of cow's milk (usually previously skimmed) or, when whole milk 
is used, by mingling the desiccated milk with sugars or baked cereal flour. 
Sometimes desiccated milk is used in mixture with a dried extract of 
malted cereals. In fact all sorts of mixtures are found on the market, 
involving, however, in nearly all cases, one modification or another of 
the above general processes of preparation. 

Composition. — Few complete analyses of these classes of foods have 
recently been made. Among the best are those of McGill,* from whose 
work the following figures have been selected, illustrating typical examples 
of foods on the market : 

* Canadian Dept. of Inland Rev. Bui. 59. 



CEREJLS, LEGUMES, VEGETABLES, /IND FRUITS. 



271 







is 










i,a 




e] 


11 

■° 2 


S 

"3 




5-i 





Z: 


S 


(2. 


-] 


hj 


5 


6-O4 


0.72 




3-94 


9 


8-12 


0.48 


0-34 


4.67 


2 


9-99 
9-41 


°-i3 
0.41 






7 




0.65 


2.26 


9 
12 


2-55 
5-77 


1. 41 
0.48 






28.24 


4-27 


8 


4.72 
2.18 


0.30 
4-45 






9 


39-54 


4-3° 


2 


5-69 


2.18 














2« 



^z 
5 



Farinaceous foods: 

Imperial granum 

Ridge's food 

Mother's food 

Robinson's barlev. , . . . . . . . 

Mi.xed foods; 

Horlick's malted milk 

Lactatcrl food 

Mellin's food 

Nestle's milk food 

Reid & Carnrick's baby food 



3-94 
5.02 
8.83 
2.gi 

63-87 

32.90 

82. 

43-84 

38-21 



13-77 

13-83 

8.60 

7-46 

14.00 
10.01 
10. 10 
10.72 
16.60 



0.49 

0-53 
2.08 
0.94 



3-57 
2-57 
3-50 
1.60 
2.78 





Starch, 

Fiber, 

etc.. by 

Differ- 
ence, 


Maltose. 


Lactose, 


Cane 
Sugar, 


Remarks. 


Farinaceous foods: 

Imperial granum 


76.60 
72.01 
69.24 
78.66 

15-68 
47-72 








Wheat starch 












Mother's food 






3.00 


Corn and wheat starch 










Mixed foods: 


49.00 
50 to 60 


30.00 


8.00 
Trace 




Lactated food. . . 


Wheat starrh 








35-34 
34-54 


8.96 
30.00 


36-34 
8 to 9 




Reid & Carnrick's baby food. . . 





Methods of Analysis. — The sample is prepared for analysis by 
grinding it sufficiently fine in a mortar or mill to pass through a i-mm. 
sieve. Moisture, fat, ash, and nitrogen are determined as in the regular 
methods for cereals (pp. 217-219). 

In determining loss of weight due to solubility of the sample in alcohol 
and water, proceed as follows:* The fat-free residue left in the So.xhlet 
apparatus, after extraction with ether or petroleum ether, is subjected 
to further extraction with 95% alcohol, till all soluble matter has been 
extracted. If 5 grams of the sample were originally taken for the fat 
extraction, this operation would require about five hours. Evaporate the 
alcoholic extract to dryness, and weigh the residue as in the case of the 
ether extract. Dry the residue left in the Soxhlct from the alcoholic 
extract, or a portion thereof, in a platinum dish over the water-bath, 
cool, and weigh. Transfer to a Gooch crucible, provided with asbestos 
* McGill, Canada Inland Rev. Dept. Bui. 59. 



2 72 FOOD INSPECTION AND ANALYSIS. 

and previously tared, a portion, the relation of which to the original weight 
taken is calculated from the moisture, ether, and alcohol extracts as pre- 
viously determined. Pass through the contents in the Gooch by suction 
from 200 to 300 cc. of cold water at room temperature, dry the Gooch 
and its contents at 100° to constant weight, cool and weigh, thus deter 
mining the solubility of the sample in water. 

According to McGill, five hours' extraction with alcohol under the 
above conditions removes all cane sugar, but probably not all the lactose, 
maltose, and dextrose, if a considerable quantity of these sugars is pres- 
ent. Water dissolves the dextrin and gum and such of the sugar as 
escapes solution in the alcohol, hence the sum of the alcohol and water 
extract is of value. In the calculation of the starch, fiber, etc., by differ- 
ence, it should be borne in mind that the result is only approximate, by 
reason of the fact that the small amount of soluble albuminoids (which 
McGill states never exceeds 25%) are reckoned in, hence a small error 
is introduced, which could be corrected, if considered worth while, by 
determining the amount of soluble albuminoids. 

Separation of the Carbohydrates can be effected by Stone's method 
(pp. 227, 228), but a very satisfactory idea of the solubility of these 
foods, which is of chief importance, can be gained by the much simpler 
modified method of IMcGill, as described in the preceding paragraphs. 

Cold-water Extract. — The equivalent of 10 grams of the moisture-free 
substance, finely ground, is weighed in a tared flask, and water added in 
several portions with gentle shaking till the contents of the flask weigh 
no grams. The flask is then corked and vigorously shaken at intervals 
during six or eight hours and allowed to stand over night. The super- 
natant liquid is then decanted into the large tubes of a centrifuge, and 
whirled till the sediment settles out. The comparatively clear liquid may 
then be readily filtered. 20 cc. of the filtrate, corresponding to 2 grams 
of the original sample, are then transferred to a tared dish, evaporated to 
dryness, and dried to constant weight, as in the determination of the 
total solids. 

Additional information may be gained from the specific gravity of 
the 10% solution of the cold-water extract, best obtained by means of a 
pycnometer. 

Reducing Sugars are determined in an aliquot part of the above 10% 
solution, diluted to proper strength. 

Effects of Subsequent Heating. — It is hardly fair in the case of those 
farinaceous foods which, according to directions, are to be subsequently 



CEREALS, LEGUMES, /VEGETABLES, AND FRUITS. 273 

subjected to heating, or boiling with water or milk, to condemn them as 
containing much insoluble matter, without comparing the tigures express- 
ing results of the analyses of the raw foods, calculated to the water-free 
basis, with those obtained on analyzing the food after boihng or otherwise 
cooking with pure distilled water, for a length of time specified in the direc- 
tions, and afterwards drying. It is possible that the presence in the food 
of diastase, or other ferment, may be depended on to hydrolyze a whole 
or a portion of the starch, and only by such comparison will this be shown. 
Microscopical Examination of the food is of value in determining 
its general character, showing especially whether or not starch is present 
in its original form, or has been converted in whole or in part. The par- 
ticular varieties of cereal grain employed are generally evident, as well 
as the presence and proportion of the different tissues of the grain. 

REFERENCES ON CEREALS, VEGETABLES, LEGUMES, FRUITS, ETC. 

Atwater, Helen W. Bread and the Principles of Bread Making. Farmer's Bui. 112. 

Beans, Peas and other Legumes as Food. Farmer's Bui. 121. 

Balland. Recherches sur les Bles, les Farines et le Pain. Paris, 1894, 

BiGELOW, MtJNSON, ToLMAN, and Howard. Fruits and Fruit Products. Bur. of 

Chem. Bui. 66. 
Blasdale, W. C. Some Chinese Vegetable Food Materials. E.xp. Sta. Bui. 68. 
Chittenden, R. H., and Osborne, T. B. Proteids of the Com Kernel. Am. Chem. 

Jour., Xni, No. 7, and XIV, No. i. 
CiVLT, H. The Microscopy of the Starches. London, 1900. 
GooDFELLOW, J. The Dietetic Value of Bread. London, 1892. 
Griffiths, W. The Principal Starches Used as Food. Cirencester, 1892. 
Hanausek, T. T. Die Nahrungs- und Genussmittel aus dem Pflanzenreiche. Kassel, 

1884. 
Harz, C. O. Landw. Samenkunde. BerUn, 1885. 
Jago, W. Science and Art of Bread Making, Chemistry and Analyses of Wheat, 

Flour, etc. London, 1895. 
Kornicke, F., u. Werner, H. Handbuch des Getreidebaues. Berlin, 1885. 
Rrug, W. H. Analytical Methods for Carbohydrates as Applied to Foods, etc. Jour. 

Frank. Inst., 1902 (CLIV), 349-401. 
Lawes and Gilbert. Composition of Wheat Grain, its Products in the Mill, and 

Bread. 
McGiLL, A. Infants' and Invalids' Foods. Canada Inl. Rev. Dept. Bui. 59.- 

Cereal Breakfast Foods. Canada Inl. Rev. Dept. Bui. 84. 

Maurizio, a. Getreide, Mehl und Brot. Berlin, 1903. 

Moeller, J. Mikroskopie der Nahrungs- und Genussmittel aus dem Pflanzenreiche. 

Berlin, 1886. 
MoLiscH, H. Grundriss einer Histocheftiie der pflanzlichen Genussmittel, Jena, 1891. 



2 74 FOOD INSPECTION AND ANALYSIS. 

MuNSON, L. S., and Tolman, L. M. Fruits and Fruit Products. Bur. of Chem. Bui. 

65, Part XIII, page 74. 
Osborne, T. B. Crystallized Vegetable Proteids. Am. Chem. Jour., XIV, No. 8. 

Oat Proteids. Conn. Exp. Station, An. Reps., 1890, page 115; 1891, page 124. 

The Proteose of Wheat. Am. Chem. Jour., XIX, No. 3. 

• Proteids of Rye. Jour. Am. Chem. Soc, 17, 429. 

Proteids of Barley. Jour. .Am. Chem. Soc, 17, 539. 

Amounts and Properties of the Proteids of Maize. Jour. Am. Chem. Soc, 19, 525. 

Osborne, T. B., and Campbell, G. F. Proteids of the Potato. Jour. Am. Chem. 

Soc, 18, 575. 

Proteids of the Pea. Jour. Am. Chem. Soc, 18, 583, and 20, 348. 

Osborne, T. B., and Voorhees, C. L. Proteids of Wheat. Jour. Am. Chem. Soc, 16, 

524- 
Osborne, T. B., and Voorhees, C. G. Proteids of the Wheat Kernel Am. Chem. 

Jour., XV, No. 6. 
Schimper, a. F. W. Anleitimg z. mikrosk. Unters. der Nahnings- und Genussmittel. 

Jena, 1886. 
Sherman, H. C. Carbohydrates of Wheat. Jour. Am. Chem. Soc, 19, 1897, page 291. 
Skinner, R. P. Manufacture of Semolina and Macaroni. Bur. of Plant. Ind. Lul. 20. 
Snyder, H. Digestibility and Nutritive Value of Bread. E.xp. Sta. Bui. 126. 
Snyder, Frisby, and Bryant. Losses in Boiling Vegetables. Exp. Sta. Bui. 43. 
Snyder, H., and Voorhees, M. A. Studies on Bread and Bread-Making. Exp. Sta. 

Bui. 67. 
Stone, W. E. Carbohydrates of Wheat, Maize, Flour, and Bread. Action of Enzvmes 

on Starches. Exp. Sta. Bui. 24. 
TscELRCH, A., und Oesterle, O. Anatomischer Atlas der Pharmakognosie und 

Nahrungsmittelkunde. Leipzig, 1893. 
VOGL, A. E. Verfalschungen und Verunreinigungen des Mehles und deren Nach- 

weisung. Wien, 1880. 

Die wichtigsten vegetabilischen Nahrungs- und Genussmittel. Wien u. Leipzig, 

. 1899. 
Wanklyn, J. A., and Cooper, W. J. Bread Analysis. London, 1886. 
Wiley, H. W. Sweet Casava. Div. of Chem. Bui. 44. 
Analysis of Cereals Collected at the World's Columbian Exposition. Div. of 

Chem. Bui. 45. 

Composition of Maize. Div. of Chem. Bui. 50. 

Wiley, H. W., et al. Cereals and Cereal Products. Div. of Chem. Bui. 13, Part IX. 
WiNTON, A. L., and Ogden, A. W. Macaroni, Spaghetti, Vermicelli, and Noodles. 

An. Rep. Conn. Exp. Sta., 1901, page 196. 
Woods and Merrill. Digestibility and Nutritive Value of Bread. Exp. Sta. Bui. 85. 

Arkansas Exp. Station Bui. 42. Wheat and its Mill Products. 
California " " " 93. Oranges and Lemons. 

" " " " loi. Prunes, Apricots, Plums, Nectarines. 

" " " " 102. Figs. 

" " "An. Reports, 1892 et seq. 



CEREALS, LEGUMES, l^EGET/tBLES, AND FRUITS. ^75 

Maine Exp. Station Bui. 54. Nuts as Food. 

" " " " 55. Cereal Breakfast Foods. 

" " " " 75. Analyses of Self-raising Flours, Pea Flours, Gluten 

Foods, Chestnuts, Malted Nuts. 
" " " " 84. Cereal Breakfast Foods. 

Minnesota E.xp. Station Bui. 74. Digestibility and Food Value of Beans. 
Penn. Dept. of Agriculture Bui. 10. Special Report on Prepared Foods for Infants 

and Invalids. 
Wyoming E.xp. Sta. Bui. 33. Composition of Prepared Cereal Foods. 

REFERENCES ON LEAVENING MATERIALS. 

Catlin, Chas. A. Baking Powders, with Special Reference to Phosphate Powders. 

Providence, 1899. 
Crampton, C. a. Baking Powders. Div. of Chem. Bui. 13, Pt. 5. 
Green, J. R. Die Enzyme. Berlin. 

The Soluble Ferments and Fermentation. 1901. 

Hansen, E. C. Practical Studies in Fermentation. London, 1896. 
JoRGENSEN, A. Die Mikro-organismcn der Giirungsindustrie. Berlin. 

Micro-organisms and Fermentation. London, 1900. 

Klocker, A. Fermentation Organisms. 1903. 

Lindner, P. Mikroskopische Betriebskontrolle in den Garungsgewerben. Berlin, 1895. 

McGiLL, A. Baking Powders. Canada Inl. Rev. Dept. Buls. 10, 26, 68. 

• Cream of Tartar. Canada Inl. Rev. Dept. Buls. 12, 26, 71. 

Matthews, Chas. G. Manual of Alcoholic Fermentation. London, 1901. 
Oppenheimer, C. Trans, by Mitchell, C. A. Ferments and their Action. London, 

1901. 
Plumiier, R. H. a. Chemical Changes and Products Resulting from Fermentation. 

London, 1903. 
VViNTON, A. L. Baking Powders. Bur. of Chem. Bui. 65, Part XV. 

Conn. E.xp. Sta. .\n. Rep., 1900, page 15. 

Michigan Dairy and Food Commission, Bui. 2, page 12; Bui. 3, page 7. 

Penn. Board of .\griculture An Report, 1897, page 166. 

North Carolina E.xp. Sta. Bui. 155. 



CHAPTER X. 

TEA, COFFEE, AND COCOA. 



TEA. 



Nature and Classification. — Tea consists of the prepared leaves or 
leaf buds of a plant belonging to the genus Thea, the Thea chinensis being 
the specific variety generally employed. 

The best teas are made from young leaves only, the Chinese teas 
being classified with reference to the age and position of the leaf on the 
young shoot. Thus, the very choicest Chinese tea, rarely found outside 
of China, is prepared from the youngest or end leaves of the shoot, which 
are scarcely more than buds, and form the tea known as pekoe lip, or 
flowery pekoe. The next leaves are the orange pekoe and pekoe, which 
produce a very high grade of tea, while next in order as to age, size, and 
grade of leaf are the souchong ist and 2d, and the congou, producing 
leas called by the same names. 

More than 50% of the tea consumed in the United States comes from 
China, and over 40% from Japan, the remainder being derived largely 
from India, Ceylon, and other East Indian ports. 

In the manufacture of tea the fresh leaves, which are nearly 80% water, 
arc rolled, withered by exposure to light, heat, and air, and finally dried 
or "fired" by treatment with artificial heat over charcoal fires, or in 
properly constructed furnaces. 

Teas are divided into two groups, black and green, which differ from 
each other, not as formerly supposed in being derived from different plants, 
but in their process of manufacture, the same species of plant furnishing 
both varieties. Genuine green tea is prepared by first steaming and 
afterwards drying the leaves while still fresh, thus retaining the bright 
color. Black tea is allowed to undergo o.xidation or fermentation by 
exposure to the sun, which gradually turns the leaves black. Less tannin 
is present in black tea than in green. 

276 



TEA, COFFEE, AND COCOA. 



m 



Composition of Tea. — Konig gives the following composition of fully 
developed tea leaves, being the mean of 50 to 70 analyses: 



Water. 


Nitroge- 
nous Sub- 
stances. 


Theine. 


Essential 
Oil. 


Fat.Chlo- 

rophyl, 

and Wax. 


Gum, 

Dextrin. 

etc. 


Tannin. 


Pectin, 
etc. 


Crude 
Fiber. 


Ash. 


9-Si 


24-5° 


3.58 


0.68 


6-39 6.44 


15-65 


16.02 


11.58 


5-65 



Though the nitrogenous substances of tea predominate in amount 
over any other class of constituents, yet, with the exception of theine or 




Fig. 66. — a, Flowery Pekoe; b, Orange Pekoe; c, Pekoe; d, Souchong, ist; e. Souchong, 2d; 
/, Congou; a, b (when mixed together), Pekoe; a, b, c, d, e (when mbted together), Pekoe 
Souchong. If there be another leaf below /, it is termed Bohea. At base of leaves 
are buds i, 2, 3, 4, from which new shoots spring. (After Money.) 

caffeine, they have been little studied. Theine, tannin, and essential 
oil give to the infusion of tea its chief characteristics. 

ZoUinski * gives the following summarized results of analyses of a 
number of the cheaper grades of Chinese black tea: 



* Zeits. anal. Chem., 1898, 37, 365. 



278 



FOOD INSPECTION /iND AN /i LYSIS. 



Water. 



Total 
Nitrogen 



Albumin- 
oid and 
Amido- 

nitrogen. 



Protein, 
NX6.25. 



Theine. 



Ash. 



Soluble 
Ash. 



Insoluble 
Ash. 



Maximum. . 
Minimum . . 
Average . . . . 



11-57 

9.96 

10.58 



4.12 
3-76 
3-93 



3-78 
3-37 
3-52 



23-83 
21.06 



2.06 
1. 14 
1-55 



6.78 
4-79 
5-94 



31-17 
28.13 
29.67 



61.03 

57-74 
59-75 



A very complete series of analyses of tea was made by Joseph F. Geiss- 
ler in 1884,* from which the following summaries are taken: 







S 
■3 


11 


-2 




3 

u 


c 
"c 
c 


£-1 


3-s 







ii 


Indian: 


Maximum. . 


6 


6.i9'3g.66 


45-64 


53. 07118. 86 


3-3 


5-79 


3-68 


2.22 


.296 




Minimum . . 




5-56,37-8°4i-32 


48.53,13.04 


1.8 


5-42 


3-24 


1-93 


-137 




.'\verage. 




S.81 


38.7742.94 


51-24 


14.87 


2-7 


5.62 


3-52 


2.12 


.178 


Oolong: 


Maximum. . 


13 


6.88 


44.02^48.87 


53-15 


20.07 


3-50 


6. 1 1 


3-71 


3-17 


.838 




Minimum . . 




S.09 


34.1040.6 


44-8 


"-93 


I -15 


5-44 


2.60 


1.84 


.266 




Average 




S.89 


37-88143-32 


5° -7 


16.38 


2.32 


5.81 


3-2 


2.68 


-507 


Congou: 


Ma.ximum. . 




9-15 


32.14j37.06 


63-85 


13-89 


2.87 


6.48 


3-52 


3-86 


I -31 




Minimum . . 




IM 


23-48,27.48 


54-5 


8.44 


1.70 


5-52 


2.28 


1.90 


-32 




Average 




8-37 


28.40134.35 


57-2 


11-54 


2-37 


5-75 


3-ob 


2.68 


.425 



Kenrick f gives the following averages of a series of analyses of tea 
made by him in 1891: 



O 10 

sg 



Substances Extracted 

by 10 Minutes' 

Infusion. 





■s 




< 


3 


!U 








3 




s 


"o 
1/1 


7.60 


3-55 


5-75 


3-69 


-6.31 


3-34 


6-54 


3-53 


4.00 


3-62 


4-72 


3-36 


5-40 


3-83 



■5g 

^ o 
o «, 

.03 

'S'o 



Congou tea. — 

Assam tea 

Ceylon tea . 

Unclassed black 

Japan 

Gunpowder . . . 
Young Hyson.. 



10 

3 
2 

13 
18 

2 
5 



23-37 
38-53 
27-45 
23-76 
30.07 

28.55 
34-22 



5-1 

7-49 
7-85 
5-40' 
9-38, 
8.00' 
10.98, 



2.65 
2.98 
2.68 
2.82 
2.45 
2-39 
2.52 



2.28 


5- 


2.16 


S- 


1.88 


5- 


2-37 


5- 


2-73 


6. 


3-7° 


7- 


2.1C 


5- 



4-51 

3-81 

3-50 
4.40 
3.20 

3-57 
3.12 



The ash of many genuine teas has been examined by Battershal % 
with the following results: 

«» " ' 

* Am. Grocer, Oct. 23, 1884. 

•j- Canada Inland Rev. Dep. BiJ. 24. 

% Food Adulteration and its Detection. 



TE/1. COFFEE, /IND COCOA. 



479 





Oolong. 

Average of 50 

Samples. 


Japan. 


Spent 
Black Tea- 


Total ash . . 


6.04 

3-44 
57.00 


5-55 
3.60 

64-55 


2.52 




Per cent soluble. .- 









Silica 

Chlorine 

Potash 

Soda 

Ferric oxide 

Alumina 

Manganic oxide. 

Lime 

Magnesia 

Phosphoric acid. 
Sulphuric acid . . 
Carbonic acid. . . 



COMPOSITION. 



11.30 

1-53 

37-46 

1.40 

I. So 

5-13 
2.10 

9-43 
8.00 
12.27 
4.18 
5 -40 



9-30 
1.60 

■41.63 
1 .12 
1. 12 
4.26 

1-3° 
8.18 

5-33 
16.62 

3-64 
S-90 



100.00 



27-75 
0.79 



16.00 

19.66 

11.20 

15.80 

1. 10 

6.70 



99.00 



Kozai * gives the following as the results of analyses made by him of 
Japanese teas: 



Unprepared 
Leaves. 



Green 
Tea. 



Black 
Tea. 



Caffeine or theine 

Ethfer extract 

Hot-water extract 

Tannin (as gallotannic acid) 
Other nitrogen-free extract . 

Crude protein 

Crude fiber 

Ash 

Albuminoid nitrogen 

Caffeine nitrogen 

Amido-nitrogen 

Total nitrogen 



3-30 
6.49 

50-97 
12. gi 
27.86 

37-33 
10.44 

4-97 
4. II 
o.g6 
o.gi 
5-97 



3.20 

5-52 

53-74 

10.64 

31-43 
37-43 
10.06 
4.92 
3-94 
0-93 
I-13 
5-99 



3-3° 
5.82 

47-23 
4.89 

35-39 
38.90 
10.07 

4-93 
4. II 
0.96 
1. 16 
6.22 



PROXIMATE COMPONENTS AND ANALYTICAL METHODS. 



Moisture. — From 2 to 5 grams are heated on a watch-glass or platinum 
dish at 100° in the air-oven to a constant weight (usually about three 
hours), calculating the moisture from the loss in weight. 

Total Ash. — A weighed portion of the sample (that used for obtaining 
the moisture may be conveniently employed) is burnt to a white ash in a 
* Bui. 7, Imperial College of Agriculture, Japan. 



2 8o FOOD INSPECTION AND /IN A LYSIS. 

platinum dish at a low red heat, and the residue cooled and weighed. 
The total ash of pure tea should not be less than 4 nor more than 8 per 
cent.* 

Soluble and Insoluble Ash. — The total ash, as obtained above, is 
transferred to a beaker with hot water and boiled for some time, after 
which it is poured upon a filter and the residue washed with hot water 
till all the soluble matter is extracted. The residue is then dried, ignited, 
cooled, and weighed, thus giving the amount of insoluble ash. The 
soluble ash is calculated by difference from the total and insoluble ash. 
At least 50% of the total ash should be soluble in water.* 

Ash Insoluble in Acid. — The portion of the ash insoluble in water 
is washed upon a tared hlter with hot 10% hydrochloric acid and further 
washed with the latter reagent till the acid-soluble matter is dissolved 
out, after which it is washed with water, dried, and weighed. 

Total Nitrogen. — This is determined by the Gunning method on 
I to 2 grams of the sample. 

Essential Oils. — Distill 100 grams of the tea with 800 cc. of water 
and shake out the distillate with several portions of ether. The residue 
from the combined ether extracts contains the volatile oil. 

Ether Extract is determined by the regular method of continuous 
extraction, using dry alcohol-free ether or petroleum ether on 2 to 5 
grams of the dried sample. 

Crude Fiber is determined as on page 218 in the residue from the 
ether extract. 

Theine or Caffeine (CsHj^N^Oa). — This alkaloid when pure exists 
in white silky needles. It is odorless and sparingly soluble in cold water, 
but more so in hot. It is less soluble in alcohol, and almost insoluble in 
ether. It readily dissolves in chloroform. It is present in tea, coffee, 
and kola. Graf f has shown that the amount of caffeine present in tea 
is in most cases proportional to the commercial value and quality. 

Detection. — Caffeine may be detected, if present in a suspected residue, 
by the so-called "murexid test," which is made with the material in a 
solid state, or with the residue from the evaporation of a liquid. A small 
quantity of the solid or powdered material is heated in a white porcelain 
dish and covered with a few drops of strong hydrochloric acid, after which 
a fragment of potassium chlorate is immediately added. The mixture 
is then evaporated to complete dryness on the water-bath, whereupon, 

* Suggested standard of the A. O. A. C. 
t Forsch, Ber., 1897, IV, 88, 89. 



TEyi, COFFEE, y4ND COCO/I. 281 

if caffeine is present, a reddish -yellow or pink color is produced. After 
cooling, the residue is treated with a very little ammonia water applied 
on the point of a stirring- rod. In the presence of caffeine, a purple color 
(that of murexoin) is produced on application of the ammonia. 

Determination of Theine or Caffeine. — Modification oj Stahlschmidl's 
Method. — Six grams of finely powdered tea are boiled in a flask with several 
successive portions of water for ten minutes each, and the combined aqueous 
extracts thus obtained are made up to 600 cc. with water. Four grams 
of powdered lead acetate are added to the decoction, which is then boiled 
for ten minutes, using a reflux condenser, or making up the loss by occa- 
sional addition of water. The solution is then poured upon a dry filter, 
and 500 cc. of the iiltrate, corresponding to 5 grams of the tea, are evapo- 
rated to about 50 cc. and enough sodium phosphate added to precipitate 
the remaining lead. The solution is then filtered, and the precipitate 
thoroughly washed, the filtrate and washings being evaporated to about 
40 cc. Finally, the solution thus concentrated is extracted repeatedly 
with chloroform in a separatory funnel for at least four times, and the 
chloroform extract evaporated to dr\-ness, leaving the caffeine, which 
is dried to constant weight at 75° and weighed. 

Determination of Tannin. — Procter's Modification oj Lowenlhal's 
Method* 

Reagents: (i) Potassium permanganate solution containing about 
1.33 grams per liter. 

(2) Tenth-normal oxalic acid solution (6.3 grams per liter). 

(3) Indigo carmine solution, containing 6 grams indigo 

carmine (free from indigo blue) and 50 cc. concen- 
trated sulphuric acid per liter. 

(4) Gelatin solution, prepared by soaking 25 grams gela- 

tin for an hour in a saturated sodium chloride solu- 
tion, heating till the gelatin is dissolved, and mak- 
ing up to a liter after cooling. 

(5) Mixture of 975 cc. saturated sodium chloride solution 

and 25 cc. concentrated sulphuric acid. 

(6) Powdered kaolin. 



Obtain the value of the potassium permanganate solution in terms 
of the tenth-normal oxalic acid solution, using the indigo carmine indi- 
cator. 

* U. S. Dept. of Agric, Div. of Chem., Bui. 13, part 7, p. S90. 



282 FOOD INSPECTION AND ANALYSIS. 

Boil 5 grams of the powdered tea for half an hour with 400 cc. of water, 
cool, transfer to a graduated 500-cc. flask, and make up to the mark. 
To 10 cc. of the infusion (filtered if not clear) add 25 cc. of the indigo 
carmine solution and about 750 cc. of water. Then add from a burette 
the potassium permanganate solution, a little at a time while stirring, 
till the color becomes light green, then cautiously drop by drop till the 
color changes to bright yellow,* or further to a faint pink at the rim. 
The volume in cubic centimeters of permanganate furnishes value a of 
the formula. 

Mix 100 cc. of the clear infusion of tea with 50 cc. of gelatin solution, 
100 cc. of salt acid solution, and 10 grams of kaolin, and shake several 
minutes in a corked flask. After settling, decant first the clear super- 
natant liquid through a filter, and finally bring the precipitate upon the 
filter. Mix 25 cc. of the filtrate (corresponding to 10 cc. of the original 
infusion) with 25 cc. of the indigo carmine solution, and about 750 cc. 
of water, and titrate with permanganate as before. The volume in cubic 
centimeters of permanganate used gives value h. 

fl = quantity of permanganate solution required to oxidize all oxidiz- 
able substances present. 

ft = quantity of permanganate solution required to oxidize substances 
other than tannin. 

.'. a — h = c, permanganate required for the tannin. Assuming that 
0.04157 gram tannin (gallotannic acid) is equivalent to 0.063 gram oxalic 
acid, the tannin in the tea is readily calculated. 

Method oj Fletcher and Alleti.'\ — This method depends upon the pre- 
cipitation of the tannin and other astringent matters in tea infusion by 
lead acetate, the point of complete precipitation being indicated by an 
ammoniacal solution of potassium ferricyanide. 

Five grams of neutral lead acetate are dissolved in water, made up to 
I liter, and after standing the solution is filtered. 

As an indicator, 0.05 gram of pure potassium ferricyanide is dis- 
solved in 50 cc. of water, and an equal volume of concentrated ammonia- 
water is added. This indicator produces a red coloration with tannin, 
gallic acid, or gallotannic acid in solution, being so sensitive that a drop 
of the indicator will detect i part of tannin in 10,000 parts of water. 

Three separate quantities of 10 cc. each of the standard lead acetate 

* Various shades of color may be produced, but the same shade should obviously be 
adopted as an end-point by the operator as when standardizing, 
t Chem. News, XXIX, 169, 189. 



TE/t, COFFEE, ztND COCOA. 283 

solution, as above prepared, are measured into as many beakers, and each 
diluted to 100 cc. with boiling water. Two grams of powdered tea are 
boiled in 250 cc. of water, and var}'ing quantities of this decoction are 
measured from a burette or pipette into the beakers containing the lead 
solution, the first beaker receiving, say, 12 cc, the second 15 cc, and 
the tliird 18 cc, in the case of black tea, and, with green tea, 8, 10, and 
12 cc, respectively. 

About I cc. of each of these trial quantities is removed from the 
various beakers by means of a pipette, passed through small filters, and 
tested with the ammoniacal ferricyanide indicator, the drops of filtered 
solution being allowed to fall directly on spots of the indicator, previously 
placed on a white slab or plate. 

It is thus easy to ascertain the approximate amount of tea solution 
which it is necessary to add to produce a pink coloration with the indi- 
cator, so that by repeated tests, nearly the right amount may be added 
at once. If no coloration in a given case is produced when a drop of 
the filtrate from the solution in the beaker is allowed to fall on the drop 
of indicator solution, a little more of the tea decoction is added, and this 
process is repeated until the pink color is apparent. 

It should be noted how much of the tea decoction is necessary to add 
to 100 cc. of pure water, that a drop of the solution may produce the pink 
coloration with the ferricyanide, and this amount should be subtracted 
from the amount of decoction found necessary to add to the known lead 
solution in the beaker. It was found by repeated experiment that 10 cc. 
of lead solution would precipitate o.oi gram of pure gallotannic acid; 
hence, carrj'ing out the process exactly as above described, 125 divided 
by the number of cubic centimeters of tea decoction required gives the 
percentage of tannin in the sample.* 

Extract. — By this term is meant the total amount of water-soluble 
matter in tea, including such compounds as tannin, caffeine, albuminous 
matter, dextrin, gum, certain parts of the ash, etc. 

The value of a tea from a food standpoint depends obviously upon 
the character and amount of the extract, rather than on the composition 
of the dry tea. The relative composition of the extract and of the insoluble 
leaves, as found by Eder, is given in the table on page 284. 

Determination. — Extract successively 2 grams of the finely powdered 
tea with seven portions of boiling water, containing 50 cc. each, decant- 
ing the extract each time, and uniting the various portions into one. 
* This process estimates the total astringent matter, all of which is counted in as tannin. 



284 



FOOD INSPECTION AND ANALYSIS. 





Extract. 


Insoluble 
Leaves. 


Dry matter . 


Per Cen 
40. 
12. 

2. 
0.6 

10. 
12. 

1-7 
0.94 

0.04 

°-i3 
0.21 


Per Cent. 
60. 
12.7 

7.2 

10. 

2-3 

0.29 

0.58 

1-03 
0.68 


Nitrogenous substances 


Theine 


Tea oil 






Extractives . . ... 


Ash 


Potash 


Lime 









After boiling the total e.xtract, it is passed through a tared filter, after 
which the insoluble residue is transferred to the filter and washed with 
boiling water. The filtrate and washings are made up to a noted volume, 
and an aliquot part is evaporated to dryness in a tared platinum dish 
to a constant weight. 

Insoluble Leaf. — The tared filter with the washed residue from the 
extract, as above obtained, is dried in an air-oven at 110° and weighed. 
If the amount of insoluble leaf is above 60%, the presence of spent or 
exhausted leaves may be suspected. 



ADULTERATION OF TEA. 

Facing. — The most common form of tea adulteration, if such it may 
be called, is the practice of "facing" the dried leaves, or treating them 
with certain pigments and coloring materials to impart a bright color 
or gloss to the tea, thus causing an inferior grade to appear of better 
quahty than it really is. This practice is more often applied to green 
tea. The materials for facing include such substances as Prussian blue, 
indigo, plumbago, and turmeric, often accompanied by such minerals 
as soapstone, gypsum, etc. Only a small amount of foreign material is 
actually added to the tea, but the adulteration consists in the deceptive 
appearance imparted thereto. 

Battershal has examined various samples of the preparations used 
in Japan for facing tea. He found in one case the following compo- 
sition: Soapstone, 47.5%; gypsum, 47.5%; Prussian blue, 5%. An- 
other sample consisted of soapstone, 75%; indigo, 25%. A third was 
composed of soapstone, 60%, and indigo, 40%. In applying the facing 
to the tea, the latter is first heated in an iron pan over the fire, the facing 



TE/t, COFFEE, AND COCO/i. 285 

mixture is then added while still hot, and the whole is stirred briskly till 
the desired color is imparted. The Chinese and Japanese do not face 
the tea which they themselves consume, but only that intended for export 
trade. 

The microscope furnishes the most ready means of detecting tur- 
meric and plumbago. The latter is detected by the bright glossy parti- 
cles, evident when a thin section of the tea leaf is examined under the 
microscope. 

Prussian blue and indigo are also evident by the microscopical appear- 
ance of the particles, detached by shaking the leaves in water. Prussian 
blue or ferric ferrocyanide is detected by the transparent bright-blue 
particles, while indigo, when viewed under the microscope, is more of 
a greenish blue. The detached particles of coloring matter often rise to 
the surface of the lifiuid, when the leaves are shaken in hot water, and 
for microscopical examination may be floated upon a glass shde. The 
color of Prussian blue is discharged by treatment with sodium hydroxide, 
while that of indigo is not. Prussian blue, if present, may be chemically 
detected in the sediment as above obtained, by dissolving in hot alkah, 
acidifying with hydrochloric acid, and then adding a drop of ferric chloride. 
A blue precipitate is indicative of the ferric ferrocyanide. 

Such minerals as gypsum and soapstone are readily separated as a 
sediment by shaking the leaves in water, and the sediment is examined 
by the appropriate qualitative methods for these substances. 

Spent or Exhausted Leaves. — These consist of leaves of tea that have 
been previously steeped or infused, and afterwards reroUed and dried. 
Such leaves are sometimes mixed with tea as an adulterant. Any con- 
siderable admixture of spent leaves is evident, both by the extremely low 
ash, and the abnormally small proportion of water-soluble ash in the 
sample. It is rare that the total ash of genuine tea is under 5%, while 
the soluble ash is seldom less than t,%. 

The ash of spent tea leaves sometimes runs as low as 2.^%,, of which 
generally not more than 0.3 to 0.8 per cent is soluble. Spent leaves are 
also naturally low in tannin and in e.xtract. 

If the extract is much below 32%, spent leaves may be suspected. 
Allen has suggested the following formula for determining the percent- 
age of spent leaves, E, in a sample of tea, R being the percentage of 
e.xtract: 

^^ (32--^) 100 . 
30 



286 



FOOD INSPECTION AND ANALYSIS. 



The use of spent or exliausted leaves as an adulterant is very rare 
at present, though formerly of common occurrence. 

Foreign Leaves as a Substitute for Tea.— This sophistication is not 
common, but the detection of leaves other than tea is readily accom- 
plished by a careful examination of the shape and character of the leaves. 
For this purpose the dried leaves are opened out by soaking a short time 
in hot water, after which they are spread upon a glass plate, and examined 
by the aid of a magnifying-glass. 

The genuine tea leaf (Fig. 67) is very characteristic, and is readily 
distinguished from other leaves. It is oval or lanceolate, 5 to 8 cm. long 

and 2 to 3 cm. wide. It is short-stemmed, 
somewhat thick and fleshy, attenuated at the 
bottom and usually pointed at the top. At a 
certain height from the base, from a third to 
a quarter up, the smooth or wavy border be- 
comes peculiarly, though not deeply, serrated in 
a regular manner, the serrations, which are 
hook-shaped, continuing to the tip of the leaf. 
Mature leaves always show these serrations, 
but they are somewhat obscure in young leaf 
buds. The latter, however, are rarely found 
in this count r}'. The veins extend outward 
from the central rib nearly parallel to each 
other, but before reaching the border, each 
bends upward to form a loop with the one 
above. 

Foreign leaves, said to be used as adulter- 
ants, are those of the willow, poplar, elder, 
birch, elm, and rose, but the writer has never 
found any of these in tea. All of them differ 
materially from the genuine tea leaf, and if 
foreign leaves are apparent in a sample under 
examination, they should be compared with various leaves collected by 
the analyst for the purpose. 

Stems and Fragments. — These, as well as "tea dust," are apparent 
by an examination of the leaves, opened out in hot water as explained 
above. The ash of tea stems and dust is abnormally high. Tht 
term "lie tea" is appUed to an imitation of tea, consisting of fragments, 
stems, and tea dust, mixed with foreign leaves, mineral matter, gum, etc. 




Fig. 67.— The Leaf of 
Genuine Tea. 



TE/t, COFFEE, AND COCOA. 287 

The ash of such "tea" has been found as high as 50%. Such imita- 
tions are now almost unknown. Make-weight substances, such as brick- 
dust, iron salts, metallic iron, sand, etc., have been found in tea. If 
present, they are to be found in the sediment, obtained on shaking out 
the tea in water. 

Added Astringents. — Catechu is sometimes said to be added to tea 
to give it increased astringency, especially to such tea as has been adulter- 
ated by the addition of exhausted tea. Hagar's method for detecting 
catechu is as follows: 

A hot-water extract of the tea (i to 100) is boiled with an excess of 
litharge and filtered. To a part of the fihrate, which should be perfectly 
clear, nitrate of silver is added. If catechu be present, a yellow floc- 
culcnt precipitate, rapidly becoming dark-colored, is formed. Pure tea 
treated in hl^e manner gives a gray precipitate. 

Spencer* adds, instead of silver nitrate, a drop of ferric chloride to 
the clear filtrate. With catechu a green precipitate is formed. 

As a matter of fact the worst forms of tea adulteration, such as the 
actual substitution of foreign leaves, once so commonly practiced, are 
now extremely rare in this country and have been for some years, by reason 
of the careful system of government inspection in force at the various 
ports of entry. The greater portion of the tea on our market to-day is 
genuine, but fraud is practiced to a considerable extent by the substitu- 
tion of inferior grades for those of good quality. This form of deception 
is in many cases beyond the power of the analyst to- detect, and properly 
comes within the realm of the professional tea-taster. 

Tea Tablets. — Finely ground tea of varj'ing quality is sometimes 
pressed into tablets, to be used by travelers and campers for preparing 
a beverage, by simply dissolving in hot water. 

The composition of one of these preparations sold under the name 
of Samovar Tea Tablets, analyzed by the Alass. State Board of Health, 
is as follows: 

Water 8 

Theine 2 

Extract 54-4 

Ash 5.4 

Soluble ash 2 

Insoluble ash 2 

* U. S. Dept. of Agric, Div. of Chem., Bui. 13, p. 885. 



288 FOOD INSPECTION AND ANALYSIS. 

Microscopical Structure of Tea. — The powdered tea may be examined 
directly in water-mount. Scliimper recommends treating the powdered 
tea with chloral hydrate or potash lye, to render it more transparent. 

By far the most characteristic element is the peculiarly shaped 
sclerenchyma, or stone cell, st, Fig. 68, entirely unlike anything to be found 
in other leaves. These cells are very irregular in form, being sometimes 
star-shaped, sometimes branched, almost always with deeply wrinkled sides, 




Fig. 68. — Powdered Tea under the Microscope. Xi6o. g, end of leaf nerve; p, chloro- 
phyll parenchyma; st, stone cells; h, hairs. The tissues were warmed in potash to 
render transparent. (After Moeller.) 

and often with sharp points. In most foreign leaves such sclerenchyma 
cells are lacking, but they are abundant in all genuine tea leaves, excepting 
rarely in the very young leaves, where they are sometimes not fully devel- 
oped. They are especially numerous in the main vein and in the stem. 
They may be seen to best advantage in a section of the stem, or midrib, 
made parallel to the surface of the leaf. To make such a section, soak 
the leaf iirst in water, and afterwards dry in alcohol. The interior of 
the leaf is composed of fibro-vascular tissue, having rounded cells full 
of chlorophyll grains. 

Other important characteristics are the peculiar hair growth on the 
under epidermis, B, which is apparent in nearly all teas, also crystals 
of calcium oxalate, which are nearly always present, even in fragments 
of tea leaves, but not often in foreign leaves.* The peculiar structure 
of the lower epidermis, B, with its numerous stomata is also to be noted. 
See Figs. 189 and 190, PI. XVIII. 

* Other leaves have crystals, but not of calcium oxalate. 



TE/t, COFFEE, AND COCOA. 289 



COFFEE. 

Nature of Coffee. — Coffee is the seed of the Coj^ca arahica, a tree 
which, when under cultivation, is not allowed to exceed twelve feet in 
height, but when wild sometimes reaches a height of twenty feet. It is 
indigenous in Southern Abyssinia, and was cultivated in Arabia in the 
sixteenth century, and in the East Indies in the seventeenth, afterward 
being introduced into the West Indies and South America. The cotYee- 
beans are usually inclosed in pairs in the bcrr\', being plano-convex with 
their flat sides together. 

When the ripe fruit is gathered, it is first dried and then freed from 
the hulls, usually by machinery-, or, in the West Indies, the green berries 
are "pulped" or "hulled" under water by a peculiar macerating machine. 
The raw beans are roasted, and afterwards ground for preparing the 
infusion. 

Brazil furnishes more than half the world's supply of cotfee, and 
nearly 75% of that consumed in the United States. 

Composition of Coffee. — Most of the coffee in the retail market is 
roasted, being sold either in the whole bean or ground. Comparatively 
little raw coffee is sold at retail. 

The constituents of raw coffee, besides water, are, in the order of their 
comparative amounts, cellulose or crude fiber, fat, protein, caffetannic 
acid, sugar, catTein, gum, dextrin, and ash. The effect of roasting coffee, 
besides driving off most of the water, is to caramelize a large part of the 
sugar, to make the bean less tough and more brittle, and, most important 
of all, to develop an empyreumatic, oily substance, known as cafjeol 
(CsHioOj), to which the characteristic flavor and aroma of coffee are 
largely due. Caffeol may be obtained by distilling an infusion of roasted 
coffee, and extracting the distillate with ether. It is a brown oil, almost 
insoluble in water. 

According to Genin, there are in raw coffee small amounts of two 
essential oils, one soluble in water, the other insoluble. During the 
roasting, these are partially transformed into the substance caffeol. 

The fat in coffee forms a considerable constituent, amounting in 
some cases to 15%. 

Caffetannic Acid (CisHigOg) is, when pure, a colorless, cr}'stalline 
compound. It exists in coffee either as a salt of calcium or magnesium, 
or, according to Payen, as a caffetannate of potassium and caffeine. 



290 



FOOD INSPECTION AND ANALYSIS. 



The following summary of analyses of coffee of various kinds made by 
Konig show in general its composition: 



Raw Coffee. 



Minimum. 



Maximum. 



Roasted Coffee. 



Minimum. 



Maximum. 



Water 

Caffeine 

Fat 

Reducing sugar. 

Cellulose 

Total nitrogen. 
Ash 



II. 4 

5-8 

16.6 

I.I 

3-5 



12.0 
1.8 

14.2 
7-8 

42-3 
2.2 
4.0 



0.4 
0.8 

10. s 
0.0 

26.3 

1-3 
4.0 



o 
2.7 
S-o 



The change in composition that takes place in roasting coffee is well 
shown by the following figures, which give the mean of analyses by Konig 
of four samples of coffee before and after roasting: 





Raw Coffee. 


Roasted Coffee. 




11.23 

I. 21 
12.27 

8-55 
18.17 
12.07 
32-58 

3-92 


I-I5 
1.24 

14-48 
0.66 
10. 89 
13-98 
45-09 

4-75 


Caffeine 


Fat 




Cellulose 




Other non-nitrogenous matter 

Ash 





'COMPOSITION OF THE ASH OF COFFEE.* 



Constituents. 



Mocha. 



Maracaibo. 



Java. 



Rio. 



Sand 

Silica (SiO,) 

Ferric o.xide (Fe,0,). . 

Lime (CaO) 

Magnesia (MgO) 

Potash (K,0) 

Soda (Na„b) 

Phosphoric acid (P.Oj) 
Sulphuric acid (SO3). . 
Chlorine (CI) 



1-44 
0.88 
0.89 
7.18 
10.68 

59-84 
0.48 

12-93 
4-43 
1-25 



0.72 
0.88 
0.89 
5.06 
11.30 
61.82 



-44 
.20 
.10 
-59 



0.74 
o.gi 
1. 16 
4-84 

11-35 
62.08 



14.09 
4. 10 
0-73 



100.00 



1-34 
0.69 

1-77 

4-94 

10.60 

63.60' 

0.17 

11-53 
.4-88 
0.48 



100.00 



The following are analyses of Mocha and East India coffees, made by 
Bell : t 

* U. S. Dept. of Agric, Div. of Chem., Bui. 13, p. 904. 

t Analysis and Adulteration of Foods. 



TE^, COFFEE, AND COCOA. 



291 



Mocha Coffee. 



Raw. 


8.98 


I 


08 


P 


SS 


8 


4b 


6 


00 


12 


60 


P 


87 




«7 


37 


95 


3 


74 



Roasted. 



East Indian Coffee. 



Raw. 



Roasted. 



Moisture 

Caffeine 

Saccharine matter 

Caffeic acid 

Alcoholic extract 

Fat and oil 

Legumin and albumin 

De.xtrin 

Cellulose and insoluble coloring matter 
Ash 



0.63 
.82 
-43 

4-74 
14.14 

13-59 
11.23 

1.24 
48.62 

4.56 



9.64 

1 .11 

8.90 

0-58 

4-31 

ir.81 

11.23 

.84 

38.60 

3-98 



I-13 

i-°5 

• 41 

4-52 

12.67 

13-41 
13- '3 

1.38 
47.42 

4.88 



Methods of Analysis. — Moisture and ash, both soluble and insoluble, 
as well as cafjcine and total nitrogen, are estimated as in the case of 
tea (q.v.). 

Fat. — Two grams of the finely powdered, dried sample are extracted 
in a Soxhlct apparatus with dry, alcohol-free ether or petroleum ether, 
till the soluble portion is removed, after which the ether is distilled off 
from the residue, and the latter is weighed. This residue consists of 
both fat and caffeine. The latter is estimated in the residue and deducted 
from the total weight. 

Crude Fiber. — This is determined by subjecting the residue from the 
ether extract to the regular process for crude fiber (p. 218). 

Caffetannic Acid. — Krug's Method* — 2 grams of the coffee are di- 
gested for thirty-si.x hours with 10 cc. of water, after which 25 cc. of 
90% alcohol are added, and the digestion continued for twenty-four 
hours more. The liquid is then filtered, and the residue washed with 
90% alcohol on the filter. 

The filtrate, which contains tannin, caffeine, fat, etc., is heated to boil- 
ing, and a boiling concentrated solution of acetate of lead is added, 
which precipitates out a caffetannate of lead, Pb3(Ci5Hj50g,), containing 
49% of lead. When this has become flocculent, it is separated by filtra- 
tion, and washed on the filter with 90% alcohol, till the washings show 
no lead with ammonium sulphide, and afterwards with ether, till free 
from fat. It is dried at 100° and weighed. 

Wt. of precipitate X 65 2 



Weight of caffetannic acid = ■ 



1263.63 



' U. S. Dept. of Agric, Div. of Chem., Bui. 13, p. 908. 



292 FOOD INSPECTION AND ANALYSIS. 



ADULTERATION OF COFFEE. 



The Standard for pure coffee proposed by the A. O. A. C. is as follows: 
Standard roasted coffee should contain not less than 10% of fat, nor more 
than 15% of carbohydrates; ash should not be less than 3%, of which 
at least 75% is soluble in water. 

Whole coffee is, as a rule, rarely adulterated at the present day, 
(hough the substitution of cheaper or inferior brands for the choicer varie- 
ties is a common practice. Formerly, artificial coffee-beans containing 
no coffee whatever, but cleverly molded to imitate the original, were 
occasionally to be found, mixed with genuine, whole coffee.* 

"Coffee pellets" are occasionally sold in bulk to dealers as an adulter- 
ant of whole coffee. These do not closely resemble the real berries in 
appearance, but are appro.ximately of the same size, and are not apparent 
to the purchaser when the whole coffee is ground at the time of purchase. 
A sample of these "pellets" examined recently was found to consist of 
roasted wheat mash, colored with red ocher. 

Adulterants to be met with in ground coffee are legion. In Massa- 
chusetts the following have been found: Roasted peas, beans, wheat, 
r3e, oats, chicor)', brown bread, pilot bread, charcoal, red slate, bark, 
and dried pellets, the latter consisting of ground peas, pea hulls, and 
cereals, held together with molasses. 

Methods of Detecting Adulterants. — These methods are, as a rule, 
physical rather than chemical. A rough test of the genuineness of ground 
coffee consists in shaking some of the sample in cold water. Pure coffee, 
under these conditions, usually floats on the surface, while the ordinary 
adulterants, such as cereals, chicory, mineral ingredients, etc., sink, 
the grains of chicory coloring the water a brownish-red as they subside. 

Macfarlane recommends the use of a saturated solution of common 
salt, in which a portion of the suspected sample, divided in small grains, 
is shaken in a test-tube. If the liquid is colored pale amber, while all 
or nearly all the material floats, the coffee is pure. Any considerable 
sediment at the bottom of the tube, accompanied by a dark-yellow to 
brown color imparted to the liquid, indicates adulteration by roasted 
cereals, or chicory, or both. 

* A sample of such imitation whole coffee consisting almost entirely of roasted wheat 
is in the possession of the writer, molded into beans with difficulty to be detected in 
appearance from those of genuine coffee, so closely do they resemble the original, even to 
the de[:)ression in the sides. 



TE/1, COFFEE, AND COCOA. 293 

A careful examination of the coarsely crushed grains of a ground 
sample with the naked eye will often serve to detect, and in some cases 
identify, certain adulterants, such as chicory and ground peas or beans. 
A magnifying-glass will aid in such an examination, and the observer 
can often separate the various ingredients of a coffee mixture, first spread- 
ing a small portion of the sample on a sheet of white pa])er. The chicory 
grains are apparent from their dark and somewhat gummy appearance, 
and can usually be recognized by crushing them between the teeth. Their 
soft consistency and bitter taste are very distinctive. The dull surface 
of the outside of the crushed coffee grains is in marked contrast to the 
polished appearance of the surface of the broken peas or beans, often to 
be found as adulterants, while fragments of broken cereal grains arc 
readily distinguished from coflfee with a low-power magnifier, though 
perhaps not easily identified by the eye alone. 

Determination of Added Starch. — Starch is determined in the finely 
powdered sample as directed on page 223. 

Microscopical Examination of Coffee. — By far the best and most 
trustworthy means for the analyst to employ in the examination of coffee 
for its adulterants is furnished by the microscope. For the purposes 
of microscopical examination, a small portion of the sample is pulverized 
in a mortar to a degree fine enough to allow the cover-glass to lie flat on 
the wetted sample, yet not so tine that it ceases to feel granular when 
rubbed between the fingers. If powdered too fine, some of the elements 
are too fragmentary to be readily recognizable. The writer linds it 
suiTicient to examine this powder in water-mount without further treat- 
ment. 

Schimper recommends maceration for twenty-four hours with ammonia, 
in order to render the tissues more transparent, using this reagent also 
as a mountant. In general the interior of the coffee tissue or endosperm 
consists of irregular polygonal parenchyma cells, (i). Fig. 69, sometimes 
with 4 and sometimes with 5 sides. 

To a large extent the cells are in fragments, but are eksily recognizable. 
They contain brilliant, colorless, spherical oil drops, and also albumin. 
The cell walls are frequently sinuous with irregular projections. 

The seed coat is also very characteristic, showing in the powder as 
occasional delicate silver-hke patches, with peculiar, spindle-shaped, 
thick-sided cells, some of which are loosened from the tissue. 

Plates XIV and XV illustrate photomicrographs of pure and aduUer- 
ated coffee. Fig. 174 shows genuine coffee, with its loose mesh of irreg- 



294 



FOOD INSPECTION AND ANALYSIS. 



ularly pentagonal cells, thick- walled, and inclosing oil drops with amorphous 
material. It is not to be expected that every pulverized sample of genuine 
coffee, mounted as above, will show in every microscopic field the even, 
continuous structure that Fig. 174 illustrates, but careful examination will 




Fig. 69. — Powdered Coffee under the Microscope. X125. (After Moeller.) i, seed 
coat (surface). 2, endosperm parenchyma. 



show in nearly every field fragments, and more or less disjointed portions 
of the polygonal cells, grouped in the form so characteristic of coffee. 
See Fig. 176. 

Chicory Under the Microscope. — Fig. 70, after Moeller, shows struc- 
tural features of chicory. The most striking elements are the fine, thick- 
walled, long-celled, parenchyma of the bark rp and bp with its delicate 
tracery, and the dotted sieve ducts g of the wood fibers. These ducts 
are tubular, resembling jointed cylinders, often with overlapping joints. 
Less common, but ver)- characteristic of chicor)', are the narrower branch- 
ing milk ducts, scli, which do not exist in roots other than chicor}', and 



TE/I, COFFEE, AND COCOA. 



29s 



by means of wliich the latter may be sometimes distinguished from allied 
roots, as the dandelion, etc. 

Fig. 178, PI. XV, is a photomicrograph of an adulterated sample of 
coffee, showing in this particular field chicory alone. It is a mass of con- 




qu fp 




Fig. 70. — Chicory Root in Tangential and Radial Sections. X 160. g, reticulated ducts 
with perforations qu; hp, wood parenchyma; /, wood fibers; rp, bark parenchyma; 
sch, milk ducts; bp, bast parenchyma; m, medullary rays. (After Moeller.) 

fused cellular tissue, traversed by two broad bands of the sieve ducts, with 
their striking, transverse, dotted markings. 

Fig. 177, PI. XV, shows a sample of coffee adulterated with roasted 
peas and pea hulls. No genuine coffee appears in this field. The chief 
masses in the center are characteristic aggregations of the round starch 
granules of the roasted pea. The rectangular billets, like bunches of 
matches, are pea hulls, or the cells composing the skin of the pea. 

Fig. 164, PI. XI, and Fig. 154, PI. IX, show the close resemblance 
between the starches of the pea and bean, both of which are commonly 
used in coffee. 

The "billets," or palisade structure of the hulls of these legumes also 
bear a close resemblance. Moeller has shown that the average length 
of the pea "billets" is 100 micromillimeters, while those of the bean 
hulls average 45. 

The effect of roasting on starches used as adulterants of coffee is to 
twist and distort the granules, in some cases destroying largely the even 



296 



FOOD INSPECTION /tND /1N/1LYSIS. 



Structure of the raw starch. Starch granules of wheat, barley, and rye, 
for example, are almost perfect circular disks in the case of the raw starch, 
while in the roasted product, the granules are twisted and distorted, 
sometimes almost forming the letter "S." 

Ground pilot crackers and stale breads show this distorted structure- 
Use of Chicory in Coffee.— Chicory is a perennial herb {Clcorium 
intybus) of the same family {Composila:) as the dandelion. The roasted 
and pulverized chicory root is so much used in ground coffee to impart 
a peculiar flavor thereto, that by many it is considered as not strictly 
an adulterant. The taste imparted to coffee by a small admixture of 
pure chicory is to some desirable, but if its unrestricted use is sanctioned 
in this manner, the door would soon be opened to a more unlimited form 
of adulteration, wherein the chicory might predominate. It is, therefore, 
best to regard chicory as an adulterant, and to require the package con- 
taining a mixture of coffee and chicor}', if sold legally, to have plainly 
printed thereon the percentage of chicory in the mixture. 

Cliicory, when roasted, consists of gum, partly caramelized sugar, 
and insoluble vegetable tissue. 

Villiers and Collin * give the following analyses of two samples of 
chicory : 



In Large 
Granules. 



In Powder. 



Soluble in water: 



Insoluble in water: 



Water (loss at 100° to 103°) 

Weight of total matter soluble in water 

Reducing sugar 

Dextrin, gum, inulin 

Albuminoids 

Mineral matter 

Coloring matter 

Albuminoids 

Weight of the total insoluble matter. . . 

Mineral matter 

Fat 

Cellulose 



16.28 
57-96 
26.12 

9-63 
3-23 
2.58 

16.40 
3-15 

25-76 
4.58 
5-71 

12.32 



16.96 

56.90 

23-79 

9-31 

3.66 

2-55 
17-59 

2.98 
26.14 

S-87 

3-92 
13-37 



Detection and Estimation of Chicory. — Various chemical tests for 
detection of chicor)' in coffee infusions have been suggested, depending on 
color reactions,! but these are, as a rule, unreliable. By far the best 
means for detecting chicory in coffee is furnished by the microscope. 

In mixtures containing coffee and chicory only, the approximate amount 



* Falsifications et .^Iterations des Substances Alimentaries, p. 234. 
t See Allen's Commercial Org. Analysis, Vol. Ill, pt. II, p. 540. 



TE/I, COFFEE, AND COCOA. 



297 



of the latter can be calculated from the specific gravity of a 10% decoc- 
tion, using conveniently the method of McGill.* A cjuantity of the pul- 
verized sample, corresponding to 10 grams of the dry substance, is weighed 
in a counterbalanced tlask, and water added till the weight of the contents 
is no grams. Fit the flask with a reflux condenser, and after so regulat- 
ing the heat that boiling begins in ten to fifteen minutes, continue the 
bofling for an hour. Remove the flame, and after fifteen minutes pass 
through a dry filter, cool, and determine the specific gravity at 15°. 
McGill found the average specific gravity of a 10% decoction as above 
carried out to be, in the case of pure coffee, 1.009S6 and in the case of 
chicory i. 02821, the difference being 0.01835. 

The specific gravity of the 10% decoction of the suspected sample 
at 15° being d, the per cent of chicory, c, can be calculated roughly by 
the formula 

(i. 02821 — (/)lOO 



c= 100 — - 



0.01835 



This method is of course inapplicable when other substances than 
chicory are present. 

Date Stones, roasted and ground, have been used to some extent as a 
cotTee adulterant. Fig. 71 shows the structural features of date stones 




Fig. 71. — ^Powdered Date Stones under the Microscope, end, endocarp; e, episperm; 
a, albumen in cross-section; a', albumen in longitudinal section. (After Villiers and 
Collin.) 

under the microscope. End represents a fragment of endocarp with its 
elongated, thick-walled cells, peculiarly arranged as shown, adjacent cells 



* Trans. Royal See. of Canada, 1887. 



298 FOOD INSPECTION AND ANALYSIS. 

often lying with axes at right angles to each other. The more evenly 
formed episperm cells, f, are thin-wallcd and of a brown color. The 
albumen, a, is made up of ver}' thick-walled, somewhat regularly arranged 
cells, indented from within with deep channels. Date stones are readily 
distinguished from coffee by these features. 

Coloring Coffee Beans. — The practice of treating raw coffee beans 
in a manner somewhat analogous to the facing of tea leaves has been 
sometimes practiced, with a view to giving to cheaper or inferior grades 
the appearance of high-priced coffee. For this purpose various pigments 
have been employed, such as yellow ocher, chrome yellow, burnt umber 
Venetian red, Scheele's green, iron oxide, turmeric, indigo, Prussian 
blue, etc., the coffee beans being first moistened with water containing 
a little gum, and shaken with the pigment. As a rule such pigments, 
especially when inorganic, are best sought for either in the ash, or in the 
sediment obtained by shaking the coffee beans in cold water, using the 
ordinary qualitative chemical methods. Organic coloring matters can 
be best extracted with alcohol. Prussian blue and indigo are tested 
for as in the case of tea leaves (p. 285). 

Glazing. — This is a more recent form of treatment of the whole bean, 
which consists in coating the beans by dipping in egg or sugar, or a mix- 
ture of the two, sometimes using various gums. Such glazing is alleged 
to improve the keeping qualities of the coffee, as well as to aid in clarify- 
ing the infusion, and if this is the sole purpose, the practice cannot be 
condemned as a form of aduUeration. If, however, it is done to give 
inferior varieties of coffee a better appearance, in order to deceive the 
consumer, it clearly constitutes adulteration within the meaning of the 
law. 

Coffee Substitutes. — A large number of preparations sold as "coffee 
substitutes" or "cereal coffee" are now on the market, most of which 
are composed, as alleged on the labels, of cereals, ground peas, etc. 
Some contain roasted wheat alone, others are mixtures of wheat and 
peas, and a few contain chicory. Some of these preparations have labels 
calling attention to the evil effects of coffee, and one of the latter class, 
extensively advertised, and purporting to contain nothing but the entire 
wheat kernel roasted and ground, was found to contain peas, and about 
30% of that "most harmful ingredient" coffee itself. 

The same ingredients are to be looked for in this class of goods as have 
been enumerated in the Hst of coffee aduUerants (p. 292), the microscope, 
as in the case of coffee, constituting the analyst's chief rehance in examin- 



TE/1, COFFEE, /tND COCOA. ^99 

ing ihem. In coffee substitutes, coffee itself should properly be con- 
sidered in the light of an aduherant. 

COCOA AND COCOA PRODUCTS. 

Nature of Cocoa. — Cocoa and the various chocolate and cocoa prepa- 
rations are made from the bean of the tree Theobroma cacao, of the family 
of Byttneriacece. This tree averages 13 feet in height, and its main trunk 
is from 5 to 8 inches in diameter. It is a native of the American tropics, 
being especially abundant and growing under best conditions in Mexico, 
Central America, Brazil, and the West Indies. 

The cocoa beans of commerce are derived chiefly from Ariba, Bahia, 
Caracas, Cayenne, Ceylon, Guatemala, Haiti, Java, Machala, Mara- 
caibo, St. Domingo, Surinam, and Trinidad. Besides these, the Sey- 
chelles and Martinique furnish a small amount. 

The plant seeds, or beans, grow in pods, varying in length from 23 to 
30 cm., and are from 10 to 15 cm. in diameter. The beans, which are 
about the size of almonds, are closely packed together in the pod. 
Their color when fresh is white, but they turn brown on drying. 

The gathered pods are first cut open, and the seeds removed to undergo 
the process of "sweating" or fermenting, which is carried out either 
in boxes or in holes made in the ground. This process requires great 
care and attention, as upon it depends largely the flavor of the seed. 
The sweating operation usually takes two days, after which the seeds 
are dried in the sun till they assume their characteristic warm red color, 
and in this form are shipped into our markets. 

For the production of the various preparations of chocolates and 
cocoa, the beans are cleaned and carefully roasted, during which process 
the flavor is more carefully developed, and the thin, paper-Hke shell 
which surrounds the seed is loosened, and is very readily removed. The 
roasted seeds arc crushed, and the shells, which are separated by winnow- 
ing, form a low-priced product, from which an infusion may be made, 
having a taste and flavor much resembling chocolate. 

The crushed fragments of the kernel or seed proper are called cocoa 
nibs, and for the preparation of chocolate they are finely ground into 
a paste and run into molds, either directly, or after being mixed with 
flavoring extract, and, in some cases, sugar and spices, according to 
whether plain or sweet chocolate is the end product. 

For making cocoa, however, a portion of the oil or fat known as the 



300 



FOOD INSPECTION AND /1NALYS1S. 



cocoa butter is first removed, by subjecting the ground seed fragments 
to hydraulic pressure, usually between heated plates, after which the 
pressed mass is reduced to a very fine powder, cither directly, or by treat 
ment with ammonia or alkalies, to render the product more soluble. Ii 
is held that the large amount of fat contained in the cocoa seeds (vary- 
ing from 40 to 54 per cent) is difficult of digestion to many, such as invalids 
and children, and hence the desirability of removing part of the fat. 

Composition of Cocoa. — The chief constituents of raw cocoa, named 
in the order of their relative amount, are fat,- proteids, starch, water, crude 
fiber, ash, theobromine, gum, and tannin. During the; roasting there 
is reason to believe a volatile substance is developed much in the nature 
of an essential oil, which gives to the product its peculiar flavor, and is 
somewhat analogous to the caffeol of coffee. 

Tannin, the astringent principle of cocoa, exists as such in the raw 
bean, but rapidly becomes oxidized to form cocoa red, to which the color 
of cocoa is due. 

Weigmann gives the following results of analyses of cocoa nibs and 
shells : 

COMPOSITION OF COCOA NIBS. 



Commercial Varieties. 



MSao 
g«.EH 






«2 



•o 



m 



Caracas 

Trinidad 

Surinam 

Port au Prince. 

Machata 

Puerto Cabello 
Ariba 



7-77 
7.87 

7-531 
7-77 
8.17 
8.08 
8.27 



-13 
.06 
.69 
-56 
.06 

■50 
•37 



1.48 

1-31 
1.66 



I-5I 



19.40 

25-30 
26.45 

5-97 
5-69 
22.9 

S-83 



15-53 

17-5° 



16.96 



6.19 
4-55 
4.30 
5-19 
4-36 
4-43 
4.48 



4.91 
3-48 
3.16 

4-15 
4-og 
4.28 
3.88 



2.06 
o. 10 

°-i3 
1.48 
0.22 
0.18 
0.14 



COMPOSITION OF COCOA SHELLS. 



Commercial Varieties. 


1 
■5 


fi 


3> 

c 

e 
e 

S 




0) 

t 

II 

g« 


U 


•s 

< 


•6 
1 


S 

is 

li 




12.49 
14.64 

13-93 
14.89 


13.18! 0.58 

14.62! 0.7d 


2.38 
3-45 
2-54 
2.01 


40.30 
44.89 
42.47 
43-32 


16.33 
15-79 
17.04 

15-25 


9.06 
6.19 
6.63 
8.08 


6.26 

0.42 
0.85 
0.27 


2. II 


Trinidad . . 


2.34 


Surinam 


16.25 
16.18 


0.78 

0-75 


2.60 


Puerto Cabello 


2.59 







TE/1, COFFEE, AhID COCOA. 



301 



The following are the summarized results of the analyses of seventeen 
varieties of cocoa seed-; and shells, made by Winton, Silverman, and 
Bailey.* 





Roasted Cocoa Nibs. 




Air-dry Material. 


Water- and Fat-free 
Material. 




Maxi- 
mum. 


Mini- 
mum. 


Mean. 


Maxi- 
mum. 


Mini- 
mum- 


Mean. 


Water 


3-i8 

4-15 
1.86 
0.07 
3-35 
1-32 
0-73 

13.06 
3.20 

12.37 
8.99 

21.07 

52-25 
2-54 

35-0 
48.00 

1-4579 
37-89 
92.90 
13.88 


2.29 
2.61 

0-73 
0.00 

1-5° 

0.82 

0.14 

11.00 

2.21 

9-3° 

6-49 

17.69 

48.11 

2.20 

32-3 
46.00 

1-4565 

33-74 

86.12 

8-83 


2.72 

3-32 
1. 16 

0.02 

2-51 
1.04 
0.40 

12. 12 
2.64 

II. 16 
8.07 

19-57 

50.12 

2.38 

33-3 
47-23 
^-4573 
34-97 
88.46 

11-54 


8.81 

3-96 
0.14 

7.12 

2.92 

1-55 
28.05 

6.56 
25.68 
18.61 
44.08 

5-41 


.'.76 
1. 60 
0.00 

3-29 
1.66 

°-3i 
23-37 

4.70 
19.80 
13.82 
38.78 

4-74 




Total ash 


7-°4 
2.46 
0.05 

5-32 
2.21 


Water-soluble ash 


Ash insoluble in acid 




Theobromine 


CatTeine 


0.86 




25.69 
5-61 
23.66 
17.10 
41-49 


Crude fiber 


Crude starch (acid conversion) 


Pure starch (diastase conversion) 

Other nitrogen-free substances 

Fat 


Total nitrogen 

Constants of fat (ether extract) : 

Melting-point, degrees C 

Zeiss refractometer reading at 40° C. . . 
Refractive index at 40° C . .... 


5-°5 






Per cent of nibs in whole bean 

" " "shells " " " 





Water 

Total ash 

Water-soluble ash 

Ash insoluble in acid 

Alkalinity of ash 

Theobromine 

Caffeine 

Other nitrogenous substances . . 

Crude fiber 

Crude starch (acid conversion). 
Pure starch (diastase conversion 
Other nitrogen-free substances. . 

Fat 

Total nitrogen 



Roasted Cocoa Shells. 



Air-dry Material. 



Maxi- 
mum. 



Mini- 
mum. 



71 
14 
.02 

•°5 

.02 

0.20 

0.04 

10.69 

12.93 

9.87 

3-36 

43-71 

1.66 

1-74 



Mean. 



4.87 

10.48 

3-67 

2-SI 

5-52 

0.49 

0.16 

14-54 

15-63 

11.62 

4.14 

46.40 

2-77 
2-34 



Water- and Fat-free 
Material. 



Maxi- 
mum. 



21.97 
6. II 

11.86 
6.47 
0.97 

0-31 
19.40 
20.72 
15-42 

5-59 
55-84 

3-41 



Mini- 


Mean. 


mum. 




5-63 


•^•^■ii 


2.16 


3-97 


0.05 


2.70 


5-32 


5-97 


0.22 


0.52 


0.04 


0.17 


11.34 


15-70 


13-71 


18.01 


10.47 


12.59 


3-65 


4-47 


47.04 


50.08 


1.87 


2-54 



'An. Rep. Conn. Agric. Ex]i. Sla., 1902, p. 



302 



FOOD INSPECTION AND ANALYSIS. 



According to Bell* the ash of cocoa nibs has the following composi- 



tion: 



Per Cent. 

Sodium chloride 0.57 

Soda 0.57 

Potash 27.64 

Magnesia 19.81 

Lime 4-53 

Alumina 0.08 

Ferric oxide 0.15 

Carbonic acid 2.92 

Sulphuric acid 4-53 

Phosphoric acid 39-20 



100.00 



Theobromine (C^HgN^O,), the chief alkaloid of cocoa, when pure, 
forms a white, crystalline powder, having a bitter taste. It is slightly 
soluble in water and alcohol, very slightly soluble in ether, insoluble 
in petroleum ether, but readily soluble in chloroform. It sublimes at 
290° to 295° C. It is a weak base, and much resembles caffeine. A small 
amount of caffeine has also been found in cocoa, but in most analyses 
is reckoned in with the theobromine. 

The Nitrogenous Substances of Cocoa, aside from the alkaloids, have 
been little studied. Stutzer has, however, separated them roughly as 
in the following analyses of four samples, of which A was manufactured 
without chemicals, B with potash, and C and D with ammonia: 



Total nitrogen 

Theobromine 

Ammonia 

Amido compounds 

Digestible albumin 

Indigestible nitrogenous substances . . . . 

Containing nitrogen 

Proportion of total nitrogen indigestible. 



3.68 
1.92 
0.06 

1-43 

10.25 

7.18 

i-iS 

31-2 



1-73 
0.03 

1-25 
7.68 
9.19 
1-47 

44-5 



3-95 
1.98 
0.46 

0-31 

10.50 

7.68 

1-23 

31-2 



D. 



3-57 
1.80 

0-33 
1-31 
7.81 
8.00 
1.28 
35-8 



METHODS OF ANALYSES. 



Moisture. — Two grams of the finely divided substance, spread evenly 
over the bottom of a flat platinum dish, are dried at 100° C. to a constant 
weight, and loss in weight counted as moisture. 

* Analysis and Adulteration of Foods. 



rf/f, COFFEE, MND COCOA. 303 

Ash. — The dish containing the above residue is brought to u dull-red 
heat over a low Bunsen flame, and kept at this temperature till a white 
ash is obtained, after which it is cooled in a desiccator and weighed. The 
ash is then boiled with water, brought upon a filter, washed, reignited, 
and the insoluble portion weighed. 

If the ash is to be examined for mineral adulterants, such as red ocher, 
etc., a much larger amount of the original substance should be taken. 

Fat. — Five grams of the sample, after drj'ing, are extracted with 
petroleum ether in a Soxhlet apparatus, and the residue, separated by 
evaporation from the solvent, is dried at 100° C. Dr}-, alcohol-free ether 
is sometimes used as a solvent, but does not give accurate results, since 
theobromine is slightly soluble in boiling ether (about i part in 600). 

Fat thus extracted from chocolate should be examined for purity 
(see p. 304), since from the high price of cocoa butter, the fat is said to 
be sometimes expressed and replaced in part by cottonseed stearin. 

Theobromine. — Total alkaloid, reckoned as theobromine, may be 
determined approximately by the same method as given for caffeine 
(p. 281). The separation of the small amount of caffeine present from 
the theobromine, and its determination, are rarely considered necessary, 
so similar are the two alkaloids in their nature and effects. 

Schmidt and Pressler * employ the following method : Ten grams 
of the sample are freed from fat by extracting with petroleum ether in a 
Soxhlet apparatus. The residue is mixed with an equal quantity of 
slaked lime, and the mixture repeatedly boiled with 80% alcohol. The 
residue left on evaporating off the alcohol is best recrj'stallized from the 
same solvent, and should be in the form of a white, crystalline powder. It 
is dried at 100° and weighed. Caffeine, if present, is included with the 
theobromine. 

Methods jor the Separation oj Caffeine and Theobromine. — The mixed 
alkaloids are best extracted with cold benzol, which dissolves the caf- 
feine, but in which theobromine is practically insoluble. 

Maupy's Method jor Estimation of Theobromine. ■\ — Extract the fat 
from 5 grams of cocoa, or from 10 grams of the chocolate with petroleum 
ether. Triturate the residue in the case of the cocoa with 2 cc. of water, 
or, in the case of the chocolate, with 4 grams 70% alcohol. Boil for an 
hour with a mixture of 15 grams phenol and 85 grams chloroform under 
a reflux condenser. Cool, filter off the extract, and shake the residue 

* Ann. der Chem., 217, 28S. 

t Jour. Pharm. Chem., 1897, V, 329-332; Abs. Analyst, XXII, 191. 



304 FOOD INSPECTION /IND ANALYSIS. 

twice with 15 grams of chloroform, allowing it to macerate half an hour 
each time, and adding the filtered chloroform to the original phenol- 
chloroform extract. Evaporate ofJ the chloroforra, add 40 grams of 
ether to the residue, and let stand for six hours. This precipitates the 
theobromine, while the caffeine, coloring substances, and an}' traces of 
fat, remain in solution. Collect the precipitate on a tared filter, wash 
with a little ether, dr}-, and weigh. 

Albuminoids. — The total nitrogen is determined by the Gunning 
method (p. 61), but if the nitrogen be multiplied by 6.25, the result, counted 
as albuminoids, is too high by reason of the theobromine. Best results 
arc obtained by first removing the alkaloids by treatment with chloroform, 
and determining the nitrogen in the residue by the regular Gunning 
method. 

Starch. — Wash 4 grams of the sample on a filter-paper wdth ether till 
free from fat. Then wash with cold water on the same filter till free from 
sugar. Subject the residue to the diastase treatment for starch, p. 223. 

Crude Fiber. — Two grams of the sample are freed from fat and the 
regular method of the A. O. A. C. (p. 218) employed. 

Cocoa Butter. — The fat of the cocoa, known as cocoa or cacao butter, 
is much used in pharmacy as a basis for ointments and to some extent 
in soap-making, so that there is a temptation to remove the fat on the 
grounds of its commercial value, as well as for the alleged reason of render- 
ing the cocoa more digestible. Cocoa butter is sometimes adulterated 
with paraffin wax and cheaper fats, such as cocoanut oil, cottonseed, 
stearin, and tallow. Tests for its purity consist in determining the melt- 
ing-point, that of pure cocoa butter being 28° to 33° C, the iodine absorp- 
tion value (which should he between 32 and 41), the saponification value 
(about 193.5), the specific gravity, which at 15° is 0.9500-0.976, and the 
butyro-refractometer reading, which at 40° is 46 to 47.8. 

ADULTERATION OF COCOA AND STANDARDS OF PURITY. 

The following are the U, S. standards:* Standard chocolate should 
contain not more than 3% of ash insoluble in water, 3.5% of crude fiber, 
and 9% of starch, nor less than 45% of cocoa fat. 

Standard sweet chocolate and standard chocolate coating are plain 
chocolate mixed wath sugar (sucrose), with or without the addition of 
cocoa butter, spices, or other flavoring material, containing in the sugar- 
* U. S. Dept. of Agric, Off. of Sec, Circ. 10. 



TE/I, COFFEE, AND COCOA. 305 

and fat -free residue no higher percentage of cither ash, fiber, or starch 
than is found in the sugar- and fat-free residue of plain chocolate. 

Standard cocoa should contain percentages of ash, crude fiber, and 
starch corresponding to those of plain chocolate, after correcting for fat 
removed. 

Standard sweet cocoa is cocoa mixed with sugar (sucrose) containing 
not more than 60% of sugar, and in the sugar- and fat-free residue no 
higher percentage of either ash, crude fiber, or starch than is found in 
the sugar- and fat-free residue of plain chocolate. 

The removal of fat, or the addition of sugar beyond the above pre- 
scribed limits, or the addition of foreign fats, foreign starches, or other 
foreign substances, constitutes adulteration, unless plainly stated on the 
label. 

The most common adulterants of cocoa are sugar and various starches, 
especially those of wheat, com, and arrowroot. Starch is sometimes 
added for the alleged purpose of diluting the cocoa fat, instead of remov- 
ing the latter by pressure, thus, it is claimed, rendering the cocoa more 
digestible and more nutritious. Unless its presence is announced on 
the label of the package, starch should be considered as an adulterant. 
Cocoa shells are also commonly employed as a substitute for, or an 
adulterant of, cocoa. Other foreign substances found in cocoa are sand 
and ground wood fiber of various kinds. Iron oxide is occasionally 
used as a coloring matter, especially in cheap varieties. 

Such adulterants as the starches and cocoa shells are best detected by 
the microscope. The presence of any considerable admixture of sugar 
is made apparent by the taste. Mineral adulterants are sought for in 
the ash. 

Addition of Alkali. — The amount of water-soluble matter in cocoa 
is very small (about 20 to 25 per cent), and in preparing the beverage, 
the desideratum aimed at is to produce as perfect an emulsion as possible. 
The legitimate means of accomphshing this is by pulverizing the cocoa 
very fine, so that particles remain in even suspension and form a smooth 
paste. Another means sometimes resorted to for producing a so-called 
"soluble cocoa" is to add alkah in its manufacture, the effect being to 
act upon a part of the fat, and produce a more perfect emulsion with less 
separation of oil particles. Such treatment with alkali is regarded with 
disfavor, even if not considered as a form of adulteration. Cocoa thus 
treated is generally darker in color than the pure article. 

The use of alkah is usually rendered apparent by the abnormally high 



3o6 



FOOD INSPECTION AND ANALYSIS. 



ash, and by the increased alkalinity of the ash, the latter constant being 
expressed in terms of the number of cubic centimeters of decinormal 
acid necessar}' to neutrahze the ash of i gram of the sample. In pure, 
untreated cocoa, the ash rarely exceeds 5.5%, and the alkahnity of the 
ash is generally not more than 3.75. In cocoa treated with alkah, the 
ash sometimes reaches 8.5%, with the alkalinity running as high as 6 
or even 8. 

Microscopical Structure of Cocoa. — Fig. 72 shows elements of the 
powdered cocoa bean, both of the shell and of the kernel. The powder 
of the latter should constitute pure cocoa, with occasional fragments 

only of the shell. The irregular lobes con- 
stituting the kernel are each inclosed in a 
membrane made up of angular cells, filled 
with granular matter. (4), (5), and (6) 
show elements of the powdered cotyledons, 
or seed kernels. The polygonal tissue of 
the cotyledon is shown in cross-section at 
(4). In the powder one finds also dark 
granular matter, bits of debris, and frag- 
ments, with masses of yellow, reddish- 
brown, and sometimes violet coloring matter, 
together with numerous starch granules and 
aleurone grains. 

The starch granules are nearly circular, 
with rather indistinct central nuclei, and 
range in size from 0.0024 to 0.0127 nim., 
averaging about 0.007 rnni. They are more 
often found in single detached grains, but 
sometimes in groups of two or three. Oc- 
casional spiral ducts, sp, are seen, but these 
are not abundant in the pure cocoa. 
The masses of color pigment are shown up with striking clearness, 
according to Schimper, by applying a drop of sulphuric acid to the edge 
of the cover-glass and allowing it to penetrate the tissue. The bits of 
coloring matter are for a short time colored a brilliant red, which, how- 
ever, soon fades. Ferric chloride colors them indigo blue. 

Schimper recommends mounting the powder in a drop of chloral 
hydrate, which soon renders most of the tissues transparent. It is some- 
times necessary to allow the chloral to act on the powder in a closed 




^S^V' 



Fig. 72. — Powdered Cocoa under 
the Microscope. X125. (After 
Moeller.) i, cross - section 
through shell parenchyma; 2, 
thick-walled cells; 3, epidermis 
of shell (surface section); 4, 
cross-section of cotyledon tissue ; 
5, 6, cotyledon parenchyma; 
7; starch. 



TEA, COFFEE, AND COCOA. 



307 



vessel for twenty-four hours, before all the elements, of pure cocoa are 
rendered transparent. If after that time opaque masses are still found, 
these are due to foreign material. 

Ammonia may be used instead of chloral with even better results, 
but this reagent requires longer treatment, soaking for several days or 
a week being sometimes necessary. 

Fig. 185, PI. XVII, shows the microscopical appearance of genuine 
powdered cocoa with its variously sized starch grains and the debris of 
the ground cotyledons. Fig. 186 shows cocoa adulterated with arrowroot. 

Cocoa Shells. — The shell parenchyma with side view of the stone- 
cell layer a and frequent spiral ducts, all characteristic of the ground 
shell, are shown at i, Fig. 72. 

In plan view the thick-walled stone-cell layer is shown at 2, and the 
spongy, outer seed-skin tissue, composed of two layers, with elongated 
cells running crosswise to each other in striated fashion, and with the 




Fig. 73. — Cocoa Shell in Surface Section. X160. ep, epicarp; p, parenchyma of the 
fruit; qu, layer of transverse cells. (After Moeller.) 



underlying hairs or so-called " Alitscherhch bodies," is shown at 3. 
The presence of an abnormally large number of yellow and brown frag- 
ments in the water-mounted cocoa specimen, even under small magnifi- 
cation, arouses suspicion of the presence of shells, the most distinctive 
elements of which are the spongy tissue, the stone cells, and the abundant 
spiral ducts, the latter being scarce in pure cocoa powder. 



3oS FOOD INSPECTION AND AN /I LYSIS. 

Cocoa shells are indicated on chemical analysis by the abnormally 
high ash and crude fiber. 

Added Starch. — This can only be approximately determined by a 
careful examination with the microscope. Long experience will enable the 
analyst to famiUarize himself with the appearance and abundance of 
starch grains of various kinds in a series of fields, so that he can roughly 
estimate the amount of each starch present in the mixture, by careful 
comparison with mixtures of known percentage composition. 

Added Sugar. — Any appreciable amount of added cane sugar is shown 
by the sweet taste. The amount of cane sugar may be determined by 
means of the polariscope, using preferably the double-dilution method of 
Wiley and Ewell, on account of the volume of the residue. For this 
purpose, extract separately with petroleum ether on filters quarter- and 
half-normal weights of the sample (6.512 and 13.024 grams), and make 
up to 50 and 100 cc. respectively, after clarification with subacetate of 
lead and alumina cream. Polarize in both cases in the loo-mm. tube, 
and multiply the readings by 4 for correction. 

Subject each solution to inversion, and from the true direct and invert 
readings, obtained by Wiley and Ewell's formula, calculate the sucrose by 
Clerget's formula. 

If a polariscope is not at hand, the sugar may be determined 
by extracting a weighed amount of the sample with cold water, and 
determining the reducing sugar, both before and after inversion, by either 
of the usual methods, the difference being the equivalent of the cane 
sugar. 

An abnormally low ash is indicative of the addition of starch or sugar 
or both. 

REFERENCES ON TEA, COFFEE, AND COCOA. 

Baker, W., & Co. The Chocolate Plant and Its Products. Boston, 1891. 
Crole, D. Tea: a Textbook of Tea Planting and Manufacture. London, 1897. 
Ewell, E. E. The Carbohydrates of the Coffee Bean. Am. Chem. Jour., 1892, 14, 373. 
Genin, V. Cafe, Chicoree, Th^, Mat^, Coca et Cacao. Analyse des Matieres Ali- 

mentaires. Girard et Dupre. Paris, 1894. 
Kenrick, a. Tea. Canada Inland Rev. Dept. Bui. 24. 
KUNZE, W. E. Quantitative Separation and Estimation of the Alkaloids of Pure 

Coffee. -Analyst, XIX, page 194. 
Lehmann, K. Die Fabrikation des Surrogatkaffees und des Tafelsenfes. Vienna, 1893. 
Lodge, J. L. Coffee: History, Growth, and Cultivation; its Preparation and Effect 

on the System. London, 1894. 



TEA, COFFEE, AND COCOA. 309 

Macfarlane, T. Coffee. Canada Inl. Rev. Dept. Buls. 3, 29, 31. 

McGiLL, A. Cocoa and Chocolate. Canada Inl. Rev. Dept. Bui. 72. 

MlCHAELis, A. Der KatTce als Genuss- und Heilmittcl nach seinen botanischen, 

chemischen, dietetischen und medicinischen Eigenschaften. 
Pearmain, T. H., and Moor, C. G. On the .\dulleration of Coffee. Analyst, 1895, 20, 

176. 
Smethane, A. Composition of Some Samples of Pure Coffee. Analyst, VII, 1882, 

page 73- 
Spencer, G. L. Tea, Coffee, and Cocoa Preparations. Div. of Chem. Bui. 13, Part VII, 

1892. 
Trillich, H. Die Kaffeesurrogate, ihre Zusammensetzung und Untersuchung. 

Munich, 1889. 
Wanklyn, J. A. Tea, Coffee, and Cocoa. London, 1883. 

WiGXER, G. W. Nitrogenous Constituents of Cocoa. Analyst, IV, 1879, page 8. 
WiNTON, A. L., Silverman, M., and Bailey, E. M. Cocoa. An. Rep. Conn. Exp. 

Sta., 1902, page 248. 

Conn. E.xp. Sta. Annual Reports, 1896 et seq. 

Maine Exp. Sta. Bui. 65. Analysis of Coffee Substitutes. 

Massachusetts State Board of Health Reports, 1882 et seq. 

North Carolina E,xp. Sta. Bui. 154. Adulteration of Coffee and Tea. 

Penn. Dept. of Agric. An. Rep., 1897, page 178. Substitutes for Coffee. 

" " " " " " 1898, pages 75 and 548. Coffee and its Adulterations. 

" " " " " " " pages 90 and 652. Chocolate and Cocoa. 



CHAPTER XI. 
SPICES. 

These aromatic vegetable substances are classed as condiments, and 
depend for their use on the pungency which they possess in giving flavor 
or relish to food. As such seasoning or zest-giving substances, they are 
of considerable importance dietetically, but from the fact that they are 
used in comparatively insignificant amount, tlie determination of their 
chemical composition or actual value as nutrients per se is of httle im- 
portance to the food economist. 

Spices are, however, of chief interest to the public analyst, because 
of all food materials they constitute from their nature a class more sus- 
ceptible than others to fraudulent adulteration of the most skilled variety. 

In many cases not only the megascopic appearance and taste of the 
skillfully adulterated article are made to counterfeit the genuine spice, 
but even the microscopical appearance is intended to deceive, since it 
is the microscope that is most useful in the detection of adulteration, and 
in many cases in the determination of the approximate amount of the 
adulterants. 

Indeed it is very rare that the microscope will fail to detect the presence 
of any foreign substance in spice, and hence its use is indispensable in 
the study of this class of foods by the analyst. Chemical methods, as 
a rule, while of secondary importance, are, however, very helpful, both 
as confirmator}' of the microscopical research, and in some cases show- 
ing instances of adulteration not readily apparent with the microscope, 
such, for example, as in the case of exhausted spices, or those deprived of 
a whole or a part of their volatile oil. Sophistication of this kind is best 
shown by the ether extract. 

General Methods of Proximate Analysis. — The following methods 
common to all the spices are for the most part those adopted provisionally 
by the A. O. A. C* Methods peculiar to special spices will be treated 

* U. S. Dept. of Agric, Bur. of Chem., Bui. 65. 

310 



SPICES. 311 

under the discussion of ihe spice in question. For these determinations 
the spices should be powdered fine enough to pass through a 60-mesh 
sieve. 

Determination of Moisture. — Richardson's Method.* — Two grams of the 
sample are weighed in a tared platinum dish and dried in an air-oven 
at 110° to a constant weight, which generally requires about twelve hours. 
The loss in weight includes the moisture and the volatile oil. The latter 
is determined from the ether extract, as described on page 312, and 
deducted from the total loss to obtain the moisture. 

McGill t determines the moisture by exposure of a weighed portion 
of the sample in vacuo over perfectly colorless sulphuric acid. The spice 
gives up its moisture before the volatile oil comes off, and any appreciable 
amount of the volatile oil, when absorbed by the acid, causes the latter 
to be discolored, so that by carefully observing the beginning of the dis- 
coloration, and removing the sample, the loss due to moisture may be 
obtained by weighing at the proper stage. The abstraction of the mois- 
ture in this manner requires about twenty-four hours. 

Determination of Ash. — The residue from the determination of 
moisture is burnt to a white ash in the original platinum dish, either 
directly over a low flame, or preferably in a muffle. If it is impossible 
to obtain a white ash, the charred mass is exhausted with water, a little 
ammonium carbonate solution is added to the aqueous extract, and the 
latter is evaporated to dryness, the insoluble residue, which has been col- 
lected on a filter and burnt, is added, and the whole is incinerated to as 
near a white ash as possible. 

The Water-soluble Ash J is found by boiling the total ash as above 
obtained with 50 cc. of water, and filtering through asbestos in a tared 
Gooch crucible, the insoluble residue being washed with hot water, dried, 
ignited, and weighed. 

The insoluble ash, subtracted from the total, leaves the water-soluble 
ash. When sand is present, its amount is assumed to be the percentage 
of ash insoluble in hydrochloric acid. The ash from 2 grams of the sub- 
stance, obtained as above described, is boiled with 25 cc. of 10% hydro- 
chloric acid (specific gravity 1.050) for five minutes, the insoluble residue 
is collected on a tared Gooch crucible, thoroughly washed with hot water, 
and finally dried and weighed. 

* U. S. Dept. of Agric, Div. of Chem., Bui. 13, pt. 2, p. 165. 
t Canada Dept. of Inland Rev. Bui. 73, p. 9. 

J Winton, U. S, Dept. of Agric, Bur. of Chem., Bui. 65, p. 55. 



312 FOOD INSPECTION AND ANALYSIS. 

Lime is determined from the ash as directed on page 264, having first 
separated the iron and phosphates. 

The sulphuric acid due to calcium sulphate (added as an adulterant) 
is determined by precipitation with barium chloride of a \tvj weak hydro- 
chloric acid solution of the ash, the separated barium sulphate being 
washed, dried, ignhed, and weighed. 

Ether Extract — Total, Volatile, and Non-volatile* — Two grams of the 
powdered substance are placed in a Schleicher and SchuU cartridge, or 
wrapped in fat-free filter-paper, and are subjected to continuous extrac- 
tion in a Soxhlet apparatus for twenty-four hours with anhydrous, alco- 
hol-free ether. t The ether solution is then transferred to a tared evapo- 
rating-dish, and allowed to evaporate spontaneously at the temperature 
of the room. After the disappearance of the ether, the evaporating- dish 
is placed in a desiccator over concentrated sulphuric acid and left over 
night, or for at least twelve hours, after which it is weighed, the residue 
in the dish being regarded as the total ether extract. 

The dish and its contents are then subjected to a heat of about 100° C. 
for several hours, taking a long time to bring the temperature up to that 
point so as to avoid oxidation of the oil. Finally heat at 110° C. till the 
weight is constant. The final residue is the non- volatile, and the loss 
in weight the volatile ether extract. 

Alcohol Extract. — Method oj Winton, Ogden, and Mitchell.X — Two 
grams of the powdered sample are placed in a loo-cc. graduated flask, 
which is filled to the mark with 95% alcohol. The flask is stoppered and 
shaken at half-hour intervals during eight hours, after which it is allowed 
to stand for sixteen additional hours without shaking, and the contents 
poured upon a dry filter. Of the filtrate, 50 cc. are evaporated to dry- 
ness in a tared platinum dish on the water-bath, and heated at iio°C. 
in an air-oven to constant weight. This method, while only approxi- 
mate, is so much simpler than the tedious operation of continuous extrac- 
tion, considering the long time required, that it is regarded as preferable 
for ordinary work, and, unless great care is taken, is nearly as accurate. 

Determination of Nitrogen. — This, in spices other than pepper, is 
best done by means of the Gunning method (p. 61). 

* Richardson, U. S. Dept. of Agric, Div. of Chem., Bui. 13, p. 165. 

t Petroleum ether may be used, yielding results which differ but slightly from those 
obtained with ethyl ether. As the latter has been used in the analyses of a large number 
o£ samples of spices, if these analyses are to be taken for standards of comparison it is evi- 
dent that the same solvent should be used 

JWintcn, U. S. Dept of Agric, Bur. of Che<n., Bui. 65, p. 56. 



SPICES. 3 ' 3 

Determination of Starch. — In spices like white pepper, ginger, and 
nutmeg that normally contain a high content of starch and very little 
other copper-reducing matter, the direct acid conversion process of starch 
determination is satisfactory. 

In spices normally free from starch, such as cloves, mustard, and 
cayenne, where a starch determination indicates the amount of a foreign 
starch present as an adulterant, it is safer to use the diastase process. 

Four grams of the powdered sample are extracted on a filter-paper 
(fine enough to retain all starch particles) first with five successive por- 
tions of lo cc. of ether, then with 150 cc. of loCJ, alcohol. Owing to 
difficulty of filtering in the case of cassia and cinnamon, Winton recom- 
mends that all washing in the determination of starch in these substances 
be omitted. The residue is washed from the filter-paper by means of 
a stream of water into a 500-cc. flask, if the direct acid conversion method 
is used, using 200 cc. of water; 20 cc. of hydrochloric acid (specific 
gravity 1.125) are added, and the method from this point on followed, 
as detailed on page 223. 

If the starch is to be determined by the diastase method, wash the 
residue from the filter-paper into a beaker with 100 cc. of water, and 
proceed as on page 223. 

Determine the dextrose in either case by the Defren method, or 
volumetrically, and convert dextrose to starch by the factor 0.9. 

Determination of Crude Fiber. — Two grams of the substance are 
extracted with ordinary ether (or the residue left from the determination 
of the ether extract may be taken) and subjected to the regular method 
for determining crude fiber, by boiling successively with acid and alkali 
(page 218). 

McGill recommends the use of the centrifuge in separating the crude 
fiber, after boiling with the alkaline solution. 

Determination of Volatile Oil. — Method of Girard and Dupre* — 
The spice is mixed with water and subjected to distilla'tion, receiving 
the distillate in a graduated cylinder. The volume occupied by the 
essential oil (which is immiscible with water) can be thus rea-d off and 
its content roughly determined. If the volatile oil is slightly soluble 
in water, separate out the water layer, having first read the volume cf 
the oil layer, and extract the aqueous solution with petroleum ether. 
Evaporate the petroleum ether extract to dryness at room temperature 

* Analvse des Malieres Alimentalres, page 655. 



314 FOOD INSPECTION /tND AN/1 LYSIS. 

in a tared dish, and add the volume due to the weight of the residue to 
the volume read off in the graduate. 

Microscopical Examination of Powdered Spices. — As a rule few 
microscopical reagents are necessary in the routine examination of 
powdered spices for adulteration, unless a more careful study of the 
structure than is necessary to prove the presence of adulterants is desir- 
able. The simple water-mounted specimen is usually sufficient to show 
the purity or otherwise of the sample. If in doubt as to the presence of 
starch in small quantities, iodine in potassium iodide should be apphed 
to the specimen, well rubbed out under the cover-glass. 

Very rarely it is helpful to treat the spice powder with ammonia or 
chloral hydrate, to render certain of the hard opaque fragments more 
transparent. When this treatment is resorted to, the material should 
be soaked for a day or more in the clearing reagent, and examined in the 
same medium on the slide. 

The presence of occasional traces of a foreign substance, when viewed 
under the microscope, is hardly sufficient to condemn the sample as 
adulterated. Unless they are evident by being persistently apparent 
in a large number of fields, such traces are apt to be accidental. 

Composition of Miscellaneous Spice Adulterants. — The chemical 
analyses of various spice adulterants commonly met with are given on 
page 315. 

CLOVES. 

Nature and Composition. — Cloves are the dried, undeveloped flowers 
of the clove tree {Caryophyllus aromalicus or Eugenia caryophyllata), 
which belongs to the myrtle family (Myrtacece). The tree is an evergreen, 
from twenty to forty feet in height, cultivated extensively in Brazil, Cey- 
lon, India, Mauritius, the West Indies, and Zanzibar. Its leaves are 
from 7.5 to 13 mm. long, and its flowers, of a purplish color, grow in 
clusters. The green buds in the process of growth change to a reddish 
color, at which stage they are removed from the tree, spread out in the 
sun, and allowed to dry, the color changing to a deep brown. Each 
whole clove consists of a hard, cylindrical calyx tube, having at the top 
four branching sepals, surrounding a ball-shaped casing, which consists 
of the tightly overlapping petals, and vnthin which are the stamens and 
pistil of the flower. In taste the clove possesses a strong and peculiar 
pungency. One of its most valuable ingredients is the volatile clove 
oil. This is composed largely of eugenol (Cj^YL^^On), which forms 70 to 



SPICES. 



315 



English-walnut shells *. 

Brazil-nut shells * 

Almond shells * 

Cocoanut shells * 

Date stones * 

Spruce sawdust * 

Oak sawdust * 

Linseed meal * 

Cocoa shells * 

Red sandalwood * 

Ground olive stones f - 





Ash. 


Ether Extract. 






_c 








51 

'0 


f2 


as 


i 


S 

> 


1 

is 

c.- 


7.69 


1.40 


0.77 


0.00 


0.12 


0-55 


9.08 


1-59 


1.06 


0.17 


0.07 


0-57 


7.80 


2.86 


2-39 


0.05 


0.16 


0.64 


7-36 


0.54 


o.i;o 


0.00 


0.00 


0.25 


8.24 


1.24 


0.76 


0.04 


0.36 


8.38 


8.77 


0.23 


0.16 


0.00 


0.07 


°-77 


5-73 


1.22 


0.32 


0.02 


0.07 


0.84 


8.71 


5-72 


1.74 


0-55 


0.04 


6.58 


10.44 


8.40 


4.66 


0.83 


I. 00 


2.99 


4.42 


0.70 


0.28 


0.07 


I .21 


11.47 


9-5° 


0.88 


0.24 


0.44 


0.06 


0.24 



1.84 
1. 01 

5-16 

I. 12 
16.72 
1.50 
6.25 
g.46 

4-77 
19-37 



>■ 1 

Sf ui O J 






0; K 0) lJ 



I c 



4 



English-walnut shells * 
Brazil-nut shells * . .. . 

Almond shells * 

Cocoanut shells * 

Date stones * 

Spruce sawdust * 

Oak sawdust * 

Linseed meal * 

Cocoa shells * 

Red sandalwood * 

Ground olive stones f 



19.30 
12.96 

22.72 
20.88 
20.88 
15.48 
17.10 
21 .15 
8.68 
6-79 



l.OI 

0-73 
0.84 

°-73 
2.19 

1-13 

1.68 

14.06 

3-iS 
1. 12 

1-73 



56-58 
50.98 
49.89 
56.19 

5-72 
64-03 
47-79 

8.30 
14.12 
52-30 
57-46 



1.69 
4.19 
1-75 
I-I3 
5-31 
0.56 
1.63 
31.81 
16.19 
3.06 
1.06 



2.08 
1-30 
1.56 
1.82 
2.34 
1. 17 
12.22 
3-90 
4-94 
2.29 



0.27 
0.67 
0.28 
0.18 
0.85 
0.09 
0.26 
5-09 
2-59 
0-49 
0.17 



75 per cent of the oil, and a sesquiterpene known as can'ophyllene. 
There are also in cloves a notable amount of fixed oil and resin, and also 
a pecuUar form of tannin. 

Ver}' few complete analyses of cloves are on record. Richardson J 
seems to have been the earliest worker in the field to give anything at 
all satisfactor)' in the way of a number of determinations of value. 

The following are maximum and minimum figures from the tabu- 
lated results of Richardson's analyses: 

* Winton, Ogden, and Mitchell, Conn. Exp. Sta. An. Rep., 1898, p. 210. 
t Doolittle, Mich. Dairy and Food Dept. Bui. 94, 1903, p. 12. 
t U. S. Dept. of Agric, Div. of Chem., Bui. 13. 



3(6 



FOOD INSPECTION AND ANALYSIS. 





1 


4, 
< 


16 




U 


1^ 




C 

Xm 



r2 

1 'u 

< 


Whole cloves (7 samples): 


10.67 

2. go 

10.18 

9-58 
5-93 


13-05 
5-50 
6.96 

10.73 
5-79 


18. 8g 
0.23 
4.40 

13-93 
3-94 


10.24 
7.12 
4-03 

7-44 
4.02 


9-75 
6.18 

13-58 

13.80 
9-38 


7- 

4-73 

5-78 

6.48 
4.20 


I. 12 
.76 
.92 

1.04 
.70 


5-43 
3.00 

5 -96 

6.20 
2.89 


22.13 

11.70 




Stems ( I sample) 


23.24 
24.18 


Ground cloves (9 samples): 




11.28 







McGill * gives tables of analyses of pure and adulterated samples of 
cloves. Analyses of upwards of twenty samples of genuine cloves, both 
whole and ground, from these tables show the following maximum and 
minimum figures: 





Maximum. Minimum. 


Moisture 


11.80 
19.63 
30.68 
10.23 
31-40 
7.00 


5-°5 

g.24 
16.25 

0.94 
22.23 

5-03 


Volatile oil 


Total volatile matter 


Fixed oil 




Ash 





McGill also made analyses of whole cloves of several varieties, the 
following table being a summary of his results: 



No. of 
Analyses. 




Moisture. 


Total 
Volatile 
Matter. 


Volatile 
Oil. 


Total 
Extract- 
ive 
Matter. 


7-4 


24-3 


17.2 


28.2 


5-0 


20.7 


14.8 


24.4 


6.2 


22.4 


16.2 


27.0 


6-7 


25-9 


19.2 


29.2 


5-5 


=3-5 


18.0 


26.5 


6.1 


24.6 


18.5 


27-5 


6-7 


23.6 


18.3 


28.1 


4-1 


18.6 


12. I 


21-3 


5-7 


21.7 


16.0 


25-5 



Fixed 
Oil. 



Penang cloves: 



Ambovna cloves: 



Zanzibar cloves: 



Maximum 
Minimum. 

Mean 

Maximum 
Minimum. 
Mean. . . . 
Maximum 
Minimum. 
Mean. . . . 



9-5 

10.8 

10. o 

8.2 

9-0 

10.7 

8.0 

9.6 



Maximum and minimum figures of thirteen samples of unadulterated 
cloves, as purchased from retail dealers in Connecticut and analyzed 
by Winton and Mitchell,! are as follows: 



* Canada Inland Rev. Dcpt. Bui. 73. 

t Conn. Exp. Sta. Rep., 189S, pp. 176-177 



SPICES. 



317 





Maximum. 


1 

Minimum. 


Ash. total . 


7.92 

18.25 

7.19 


5-99 
11.03 

4-87 




" " non-volatile 





Winton, Ogden, and Mitchell * give more complete analyses of eight 
samples of whole cloves of known purity, and two samples of clove stems 
as follows: 





Moisture. 


Ash. 


Ether Extract. 


Alcohol 
Extract. 




Total. 


Soluble in 
Water. 


Insoluble 
in HCl. 


Volatile. 


Non- 
volatile. 


Maximum 


8.26 

7-03 
7.81 

8.74 


6.22 
5. 28 
5.92 
7-99 


3-75 
3-25 
3 -.58 
4.26 


0-13 
0.00 
0.06 
0.60 


20.53 

17.82 

19.18 

5.00 


6.67 
6.-24 
6.49 
3-83 


15-58 

13-99 

14.87 

6.79 




Mean 


Clove stems, mean 





Reducing 
Matters 
by Acid 
Conver- 
sion . as 
Starch. 


Starch by 
Diastase 
Method. 


Crude 
Fiber. 


Nitrogen, 
X6.2S. 


Oxygen 

Absorbed 
by Aque- 
ous Ex- 
tract. 


Querci- 
tannic 
Acid. 


Total 
Nitrogen. 


Maximum 

Minimum 


9-63 
8.19 

8.99 
14-13 


3-15 
2.08 

2-74 
2.17 


9.02 

7.06 

8.10 

18.71 


7.06 

s.ss 

6.18 
5.88 


2.63 
2.08 

2-33 
2.40 


20.54 
16. 2i; 
18.19 
18.79 


I-13 
0.94 
0.99 
0.94 


Mean 

Clove-stems, mean 



The Tannin Equivalent in Cloves. — The amount of tannin in cloves 
was shown by EUis to be so constant as to be of valuable assistance as a 
guide to their purity. The actual determination of tannin is, however, 
a long and difficult proceeding, and Richardson f has pointed out that 
it is not necessary, but that simply using the first part of the Lowenthal 
tannin process, and noting the "o.xygen absorbed" as expressed by the 
oxidizing power of permanganate of potash on the material after extrac- 
tion with ether, is quite as useful as determining the tannin, and is in 
effect proportional to the tannin present. The result is sometimes 
expressed as in Richardson's figures above, as the oxygen equivalent, or 
as qucrcitannic acid. 

Determination of Tannin Equivalent-! — Reagents: Indigo Solution. — 
Six grams of the indigo salt § are dissolved in 500 cc. of water by heat- 

* Conn. Exp. Sta. Rep., 1898, pp. 206, 207. 

t U. S. Dept. of Agric, Div. of Chem., Bui. 13, p. 167. 

X Winton, U. S. Dept. of Agric, Bur. of Chem.. Bui. 65, p. 60. 

§ The quality of the indigo used is of great importance since with inferior brands it is 



3iS FOOD INSPECTION AND ANALYSIS. 

ing. After cooling, 50 cc. of concentrated sulphuric acid are added, 
the solution made up to a liter and filtered. 

Standard Permanganate Solution. — Dissolve 1.333 grams of pure 
potassium permanganate in a liter of water. This should be standardized 
by titrating against 10 cc. of tenth-normal oxalic acid (6.3 grams pure 
crystallized oxalic acid in 1,000 cc), diluted to 500 cc. with water, heated 
to 60° C, and mixed whh 20 cc. of dilute sulphuric acid (1:3 by volume). 
The permanganate solution is added slowly, stirring constantly, till a 
pink color appears. 

Two grams of the material are extracted for twenty hours with pure 
anhydrous ether. The residue is boiled for two hours with 300 cc. of 
water, cooled, made up to 500 cc, and filtered. 

Twenty- five cc. of the filtrate are pipetted into a 1200-cc. flask, 750 cc. 
of distilled water are added and 20 cc. of indigo solution. 

The standard permanganate solution is then run in from a burette 
a drop at a time with constant shaking, until a bright golden yellow color 
appears, which indicates the end-point. Note the number of cubic cen- 
timeters required, represented by (a). 

In a similar manner determine the number of cubic centimeters of 
standard permanganate solution consumed by 20 cc. of the indigo solu- 
tion alone, represented by (b), and subtract this from (a). 

The oxygen equivalent, or, as it is sometimes called, the "oxygen 
absorbed," is calculated from the equivalent in tenth-normal oxalic acid 
of the number of cubic centimeters of standard permanganate repre- 
sented by a — h. 10 cc. of tenth-normal oxalic acid are equivalent to 
0.008 gram of oxygen absorbed, or 0.0623 gram of quercitannic acid. 

Microscopical Examination of Cloves. — Unless the finely powdered, 
water-mounted sample is well rubbed out under the cover-glass, many 
of the masses of cellular tissue will be too dense to recognize. With a 
little care, however, it is possible to make a very satisfactory water mount, 
though by soaking for twenty-four hours in chloral hydrate solution the 
more opaque masses are rendered very translucent. 

Fig. 74, from Moeller, shows some of the characteristics of powdered 
cloves. The outer skin of the calyx tube is shown at (i) with its polyg- 
onal cells and large oil spaces showing through them; (2) shows the 
epidermis of the outer part of the lobes or wings of the calyx, with stomata 

impossible to get a sharp end-point. The indigo solution should be made from the very 
best variety of sulphindigotate, which may be obtained from Grucber & Co., of Leipzig, or 
Gehe & Co., of Dresden, under the name of carminium cccndeum. 



SPICES. 



319 



surrounded by irregularly shaped cells; (3) represents the epidermis 
of the petals, with crystals of calcium oxalate; a cross-section of the epi- 
dermis of the calyx is shown at (4); (5) shows the parenchyma, wi;h 
calcium oxalate crystals and with one of the slender spiral ducts; (6) 
and (7) represent in cross-section and longitudinal section respectively 
the parenchyma of the middle layers of the calyx, one of the rounded, 
triangular pollen grains being shown at (12). 




Fig. 74. — Powdered Cloves under the Microscope. X125. (After Moeller.) 

Characteristics of clove stems, which are frequently used as adulter- 
ants of cloves, are found in (8), (9), (10), and (11). Stone cells of 
the outer skin and the inner portion of the clove stem are shown 
at (8) and (9) respectively; (10) shows one of the vascular ducts, 
and (11) two of the bast fibers. Both the vascular ducts and the 
bast fibers are very characteristic of clove stems. Pure cloves have 
no stone cells and comparatively few bast fibers. Stems under the 
microscope show a large number of bast fibers and frequent stone 
cells. 

A plain water-mounted slide rarely shows all the structural details 
depicted in Fig. 74, but is nearly always sufficiently characteristic to 



320 FOOD INSPECTION AND ANALYSIS. 

prove the purity of the sample. Fig. 220, PL XXV, shows the actual 
appearance of powdered cloves, mounted in water and examined under 
a magnification of 130. The general appearance of the cellular tissue 
is that of a loose, spongy mass filled with brown, granular material. 
Throughout the masses of tissue are to be seen small oil globules. 

Cloves have no starch whatever. Aside from the stems, cloves are 
sometimes adulterated with clove fruit or "mother cloves," which have 
a small amount of a sago-like starch, and also contain some stone cells. 

Adulteration of Cloves. — The U. S. standard for pure cloves is as 
follows: Volatile ether extract not less than 10%; quercitannic acid, cal- 
culated from the total oxygen absorbed by the aqueous extract, should 
not be less than 12%; total ash should not exceed 8%; ash insoluble in 
hydrochloric acid should not exceed 0.5%, and crude fiber should not 
be more than io%. 

Clove Stems are v?ry frequent adulterants of cloves and possess some 
slight pungency. They are commonly identified under the microscope 
by the large number of bast fibers and stone cells, and should not be 
found in pure cloves in excess of 5%. 

Allspice, being considerably cheaper than cloves, is sometimes used 
as an adulterant. It is readily recognized by the characteristics described 
on page 324. 

Other Adulterants commonly found are cereal starches (especially 
corn and wheat) and ginger (for the most part "exhausted"). Besides 
the above, pea starch, rice, turmeric, charcoal, sand, pepper, ground fruit 
stones, and sawdust have been found in samples of cloves examined in 
Massachusetts. 

Exhausted Cloves, both whole and in powdered form, are not infre- 
quently found on the market. These have been deprived of a portion 
of the volatile oil, and are much less pungent than the pure article, so 
that the difference in taste between the two varieties is quite marked. It 
is, however, rare that powdered cloves are sold consisting entirely of 
the exhausted variety, the more common practice being to mix from 
10 to 25 per cent of exhausted cloves with the pure powder, so that the 
sophistication is less apparent. 

A determination of the volatile oil is the only reliable means of show- 
ing whether or not the material has been wholly or in part exhausted, 
though Villier and Collin claim that under the microscope an exhausted 
sample of cloves shows the oil glands to be nearly empty, or to inclose 
much smaller droplets of oil than the pure variety. 



SP/CES. 



3JI 



With the exception of exhausted cloves, the presence of nearly 
every foreign ingredient is best and most quickly shown by the use of 
the microscope, though much information as to the purity of the sample 
can be gained by the ether extract, the percentage of ash, and of crude 
fiber.* 

Cocoanut Shells. — Figs. 226 and 227, PI. XXVII, show samples of cloves 
adulterated with ground cocoanut shells. The long, spindle-shaped, yellow- 
brown and deeply furrowed stone cells of the adulterant with their thick 
walls and central branching pores are unmistakable. The dark-brown 
contents of the cells turn reddish brown when treated with potassium 
hydroxide. The anatomy of the cocoanut, including the shell, has been 
carefully studied by Winton.f 

Fig. 75, after Winton, shows elements of powdered cocoanut shell 
under the microscope, st are the dark, elongated, yellow, porous stone 




Fig. 75. — Cocoanut-shell Powder. si, dark-yellow stone cells with brown contents; 
(, reticulated trachea; sp, spiral trachea; g, pitted trachea; w, colorless, and br, 
brown, parenchyma of mesocarp; /, bast fibres, with stigmata (sle). X i6o. (."Vfter 
Winton.) 

cells with their brovm contents, these stone cells being the most dis- 
tinctive characteristic of the ground shells. /, sp, and g are the various 
forms of trachea; 7t' and br are respectively colorless and brown paren- 
chyma of the mesocarp or outer coat, portions of which always adhere 
to the nutshell and are ground with it. 

* Note especially the sharp distinction between these values in the case of pure cloves 
and of clove stems in Richardson's table. 

t The Anatomy of the Fruit of the Cocoanut. Conn. Exp. Sta. Rep., 1901, p. 208. 



322 



FOOD INSPECTION AND AN /t LYSIS. 



Fig. 264, PI. XXXVI, shows a photomicrograph of powdered cocoanut 
shells mounted in gelatin. The long, spindle-shaped stone cells are 
especially apparent. 

Cocoanut shells are very common adulterants of various spices besides 
cloves, especially of allspice and pepper. In the following tabulated 
results of analyses by Winton, Ogden, and Mitchell * are shown the wide 
deviation between the chemical constants of cocoanut shells and several 
of the spices in which they appear as adulterants. 



Water 

Total ash. 

Ash soluble in water 

Ash insoluble in hydrochloric acid 

Volatile ether extract 

Non-volatile ether extract 

Alcohol extract 

Reducing matters, as starch, acid conversion 

Starch by diastase method. ....'. 

Crude fiber .'.^ : 

Total nitrogen X 

Oxygen absorbed by aqueous extract. . . . 
Quercitannic acid equivalent 



Black 
Pepper. 



11.96 

4.76 

2-54 

0.47 

1. 14 

8.42 

g.62 

38 63 

34- 15 

13.06 

2.26 



Cloves. 



/ ■ 
5- 
3- 
o, 

ig, 
6, 

14 



92 
58 
06 
18 
49 
87 
■99 
•74 
. 10 

•99 
■33 
■19 



Allspice. 



9.78 

4-47 

2.47 

0.03 

4^05 

5 84 

11.79 

18.03 

3^04 

22.39 

0.92 

1.24 

9.71 



Nutmeg. 



3-63 
2.28 
0.86 
0.00 
3.02 
36.70 
10.77 

25-56 
23.72 

251 
1.08 



Cocoanut 
Shells. 



736 
0.54 
0.50 
0.00 
0.00 
0.25 

I . 12 
20.88 

0-73 
56.19 
0.18 
0.23 
1.83 



ALLSPICE, OR PIMENTO. 

Nature and Composition. — Allspice is the dried fruit of the Eugenia 
pimenta, an evergreen tree belonging to the same family {Myrtacea) 
as the clove. It is indigenous to the West Indies, and is especially cul- 
tivated in Jamaica. '^i 

The allspice berrv is^ grayish or reddish brown in color, and is hard 
and globular, measuring from 4 to 6 mm. in diameter, being surmounted 
by a short style. This is imbedded in a depression, and around it are 
the four lobes of the caly.x, or the scars left by them after they have fallen 
off. The berry has a wrinkled, ligneous pericarp, with many small 
excrescences fdled with essential oil. The pericarp is easily broken 
between the fingers, showing the berry to be formed of two cells with a 
single, brown, kidney-shaped seed in each, covered with a thin, outer 
coating, inclosing an embryo rolled up in a spiral. 

The berries arc gathered when they have attained their largest size, 
but- before becoming fully ripe. If allowed to mature beyond this stage, 
some of the aroma is lost. 



* Conn. Ag. E.xp. Sta. Rep., 1901, p. 225. 



SPICES. 



3*3 



Though considrrably less pungent than other spices, allspice possesses 
an aroma not unlike cloves and cassia. In chemical composition it most 
resembles cloves, containing both volatile oil and tannin ; but, unlike 
cloves, it contains much starch, the starch being contained in the seeds. 
The volatile oil of allspice is very similar to clove oil. It is slightly lasvo- 
rotary, and is composed of cugenol and a sescjuiterpene not determined. 
It is present in allspice to the extent of 3 to 4.5 per cent. The boiling- 
point of the oil is 255° C. 

Authoritative full analyses of allspice are even more meager than 
of cloves. Analyses of one sample of whole allspice and five samples 
of the ground spice, made by Richardson,* are thus summarized: 







< 






IJ 


11 qj 


c 


Nitrogen. 


Tannin 
Equivalent. 




Whole 


6. 19 


4.01 


5-15 


6.15 


59.28 


14.83 


4.38 


.70 


10.97 2.81 


Ground: 


Maximum 


8.82 


5-53 


3-32 


6.92 


58-24 


23.60 


S-42 


.87 


12.74 3-3^ 


Minimum 


S-Si 


3-45 


1.29 


1.60 


SS-9° 


13-45 


4-03 


.67 


4.32 I. II 



Seventeen samples of unadulterated allspice, as sold on the Connect- 
icut market, were analyzed by Winton and Mitchell ,t with maximum 
and minimum results as follows: 



Ash. 


Maximum. 


Minimum. 


Total 


7-51 

-95 

3-50 

6.22 


4-34 
.40 

1-34 
3-78 


Insoluble in hydrochloric acid (sand). . 
Ether extract, volatile 







Three samples of pure whole allspice were more fully analyzed by 
Winton, Mitchell, and Ogden with the results given on page 324.J 

The Tannin Equivalent in Allspice. — Tannin is present in allspice, 
though to a less extent than in cloves. The exact amount present is 
rarely determined, but rather the "oxygen equivalent," or quercitannic 
acid, as explained on page 317, the determination being carried out as 
there detailed. 



* U. S. Dept. of Agric, Div. of Chem., Bui. 13, p. 229. 
t An. Rep. Conn. E.xp. Sta., 1898, pp. 178, 179. 
J Ibid., pp. 208, 209. 



324 



FOOD INSPECTION /iND ANALYSIS. 





Moisture. 


Ash. 


Ether Extract. 






Total. 


Soluble 
in Water. 


Insoluble 
in HCl. 


Volatile. 


Non- 
volatile. 


Extract. 




10-14 

9-45 
9.78 


4.76 
4.15 
4-47 


2.6g 
2.29 
2-47 


0.06 
0.00 
0-03 


5-21 
3-38 
4-05 


7-72 
4-35 
5-84 


14-27 

7-39 
11-79 


"Minimum 


Average 





Reducing 








Oxygen 




Matters 
by Acid 


Starch 
by 


Crude 


Nitrogen, 


Absorbed 


Querci- 


Conver- 


Diastase. 


Fiber. 


xe.js. 


ous Ex- 


Acid. 


sion, as 












Starch. 












20.65 


3-76 


23.98 


6-37 


1-59 


12.48 


16-56 


1.82 


20.46 


5-19 


1-03 


8.06 


18-03 


3-°4 


22.39 


S-75 


1.24 


9.71 



Total 
Nitrogen. 



Maximum 
Minimum 
Average . . 



1.02 
0.83 
0-92 



Microscopical Examination of Powdered Allspice.^ — By soaking the 
powder twenty-four hours or more in chloral hydrate, many of the harder 
portions are rendered much more transparent than would otherwise 
be possible. Fig. 76, after Moeller, shows the microscopical structure 
of various elements that go to make up allspice powder. 

The epidermis, or outer layer of the berry, is shown at (i) in cross- 
section, and in plan view at (2) with its small cells. Just beneath the 
outer coat are the large oil spaces (16) and still further below the stone- 
cells (ic). The fruit parenchyma (3) has vascular tissues running through 
it. (4) and (5) are the inner epidermis and stone cells of the dividing 
partitions between the seeds. Small hairs connected with the outer 
epidermis are shown at (6). (7) and (8) show in cross-section a portion 
of the seed-shell and inclosed seed or embryo, with the starch (8a) and 
the colored lumps of gum or resin (Sfc) of a port-wine color. These colored 
cells exist in the seed coating, and, although only one is here shown, 
constitute a very important and striking characteristic of allspice. (9) 
represents the spongy parenchyma of the seed shell, and (10) shows its 
epidermis. In the parenchyma of the fruit and of the partitions between 
the cells are seen, but not always plainly, minute crj'stals of calcium oxa- 
late (see (4) and (5)). 

These details so closely drawn by Moeller are idealized, but serve 
well to indicate what should be looked for. In practice the water- 
mounted specimen shows all the characteristics necessary to identify 
pure allspice, and most if not all its adulterants. In fact pimento is one 
of the easiest spices to identify under the microscope, by reason of its 
striking characteristics. 



SPICES. 



325 



Three distinctive features arc especially typical, viz. : First, the starch 
grains, which are very uniform in size, measuring about 0.008 mm. in 
diameter, being nearly circular as a rule, and often arranged in groups 
not unlike masses of buckwheat starch. Ordinarily these masses con- 
tain fewer granules than do those of buckwheat. The granules are 




Fig. 76. — Powdered Allspice under the Microscope. X12S. (After Moeller.) 



smaller and more inclined to the circular than to the polygonal form, 
while in many cases they have distinct central hyla. The starch grains 
are very numerous and are found in nearly every field. See Fig. 195 PI. 
XIX. 

A second distinctive feature of allspice is the stone cells, of which there 
are many. These are more often colorless, and in most cases very large 
and plainly marked. They are sometimes seen singly and at other 
times grouped together. Frequently they are attached to pieces of brown 
parenchyma. 



326 FOOD INSPECTION /1ND ANALYSIS. 

The third and most characteristic feature of allspice powder under 
the microscope is the striking appearance of the lumps of gum or resin, 
which are cells of a more or less deep port-wine or amber color. These 
are contained in the deUcate epidermis of the seed coat, and are very 
striking, occurring sometimes in isolated bits, and in other cases in aggre- 
gations of from 2 to 4 or even 6 to 8 cells. These resinous lumps appear 
plainly in Fig. 194, PI. XIX. Droplets of oil are occasionally seen, but 
not in profusion. As a rule the oil is forced out of its large containing 
cells and into the surrounding tissue by the process of drying. 

Adulteration of Allspice. — According to the U. S. standard for all- 
spice, (juercitannic acid should not be less than 8%, total ash not more 
than 6%, ash insoluble in hydrochloric acid not more than 0.5%, crude 
fiber not more than 25%. The most common adulterants found in 
powdered allspice are cocoanut shells and the cereal starches. Besides 
these the writer has found in Massachusetts, peas, pea hulls, exhausted 
ginger, cayenne, olive stones, pepper, and turmeric. To this list may 
be added clove stems, which are on record as a not uncommon adulterant 
in some localities. All of these are to be readily recognized by a care- 
ful microscopical examination. 

CASSIA AND CINNAMON. 

Nature and Composition. — The terms cassia and cinnamon are 
interchangeable in commerce, though, strictly speaking, they represent 
two separate and distinct species of the genus Cinnamomum, belonging 
to the laurel family {Lauraceai). True cinnamon is the bark of Cinna- 
momum zeylanicum, a tree from 20 to 30 feet high, having horizontal 
or drooping branches, and native to the island of Ceylon, but cultivated 
also in some parts of tropical Asia, in Sumatra, and in Java. The entire 
yield of pure Ceylon cinnamon is extremely small, and but little of it is 
found in this country. It is the very thin, inner bark of the tree, and is 
of a pale, yellovdsh-brown color, being found on the market in long, cyhn- 
drical, quill-like rolls or pieces, the smaller rolls being inclosed in the 
larger. The outer surface is marked by round dark spots, correspond- 
ing to points of insertion of the leaves, and it is also furrowed length- 
wise by somewhat wavy, Ught-colored Unes. The inner surface of the 
bark is darker colored, and has no lines. In thickness the bark varies 
from 1.5 to 3 mm. Both the inner and outer coatings of the bark of 
Ceylon cinnamon are usually removed in the process of preparation, so 



SPICES. 



327 



that it is of a much cleaner and more even texture than the cassia bark, which 
is thicker and heavier by reason of the outer cork layer usually left on it. 

The cheaper and more common cassia is the bark of the Cinna- 
momum cassia, which comes from China, Indo-China, and India. It is 
of a darker color than that of cinnamon, of coarser texture, and as 
a rule about four times as thick. Most varieties of cassia bark are less 
tightly rolled than cinnamon, and are not arranged one within the other 
in layers. The outer surface is marked by elhptical spots left by the 
leaves, and by small, dark-brown, wart-like protuberances. Cassia does 
not have the wavy, light-colored Unes found in the cinnamon. Both 
cinnamon and cassia barks are very aromatic in taste, somewhat astrin- 
gent, and slightly sweet. 

Cassia buds are the dry flower buds of China cassia, and are found 
in the market both in whole and in powdered form. Powdered cassia 
often consists of a mixture of several varieties of bark, while the cheaper 
grades sometimes contain an admixture of the ground buds. 

The best grade of cassia is that from Saigon, while the cheapest is 
the Batavia cassia. 

The odor of cassia and cinnamon bark is due to the volatile oil, of 
which from i to 2 per cent is usually found. Cassia and cinnamon oil 
greatly resemble each other, the principal constituent in cither case being 
cinnamic aldehyde, CoH^CHrCH.CHO. Besides this, one or more esters 
of acetic acid are present. Both oils are very pungent and intensely sweet. 

Starch is present in cassia to the extent of from 16 tO-3ct pen-cent. 
A very small amount of tannin is found, as well as cinnamic acid and 
mucilaginous matters. Cassia buds are somewhat similar in com- 
position to the bark. They have, however, less starch and crude liber, 
and higher contents of volatile oil and nitrogen than the bark. 

Richardson * has made analyses of a few samples of pure whole cinna- 
mon and cassia, from which the following are taken: 









l-l 


















^ 


< 


><^ 


5 -40 


4-55 


i-°S 


7-43 


3-40 


.82 


4-79 


5-5« 


3-59 


17-45 


8.23 


3-Si 


9-32 


2.48 


■55 






I" 



Ceylon cinnamon, i 

2 

Cassia bud? 

Cassia bark (4 samples) : 

Maximum 

"Minimum 



1.66 
1.58 

5-21 

2.13 
-74 



33.08 2.98 
25.63 3.80 
8.60 7.00 



26.29 
14-33 



4-55 
2.63 



51.28 
56.84 
65-23 

65-33 
48.65 



.48 
.62 



-73 
.42 



* U. S. Dept. of Agric, Div. of Chem., Bui. 13, p. 221, 



ji8 



FOOD INSPECTION AND ANALYSIS. 



Winton, Ogden, and Mitchell's* results of analyses of whole samples 
of cinnamon, cassia, and cassia buds are thus summarized: 



Moisture. 



Ash. 



Total. 



Soluble 

in 
Water. 



Insoluble 
in HCl. 



Ether Extract. 



Volatile. 



Non- 
volatile. 



Ceylon cinnamon (6 samples) : 

Maximum 

Minimum 

Average 

Cassia bark (20 samples): 

Maximum 

Minimum 

Average 

Cassia buds (2 samples): 

Average 



10.48 

7-79 
8.63 

II. 91 

6.53 
9.24 

7-93 



5-99 
4.16 
4.82 

6.20 
3.01 
4-73 

4.64 



•71 

.40 
,87 



2.52 
0.71 
1.68 



0.58 
0.02 
0-13 

2.42 
0.02 
0.56 

0.27 



1.62 
0.72 
1-39 

S-I5 
0-93 
2.61 

3-88 



1.68 
1-35 
1-44 

4-13 
1-32 
2.12 

3-96 





Reducing 






Alcohol 


Matters 

by Acid 

Conversion, 


Crude 


Nitrogen, 


Extract. 


Fiber. 


X6.35. 




as Starch. 






13.60 


22.00 


38.48 


4.06 


9-97 


16.65 


34-38 


3-25 


12.21 


19.30 


36.20 


3-70 


16.74 


32.04 


28.80 


5-44 


4-57 


16.65 


i7-°3 


3-31 


8.29 


■^i-i^ 


22.96 


4-34 


10.88 


10.71 


13-35 


7-53 



Total 
Nitrogen. 



Ceylon cinnamon (6 samples) : 

Maximum 

Minimum 

Average 

Cassia bark ( 20 samples) : 

Maximum 

Minimum 

Average 

Cassia buds (2 samples): 

Average 



0.6s 
0.52 
0-59 

0.87 

0-53 
0.69 

1.20 



Structure of Powdered Cassia under the Microscope. — Fig. 77, 
from Moeller, shows various elements of cassia bark as veiwed microscop- 
ically, (i) shows in cross-section a portion of the cork and outer layer 
of the bark rind, with flat cells nearest the surface, having somewhat 
thick walls and reddish-brown contents, and, farther in, the cells s, with 
mucilaginous material. 

The stone cells of the intermediate layer of bark are shown at (2). 
Here the tendency of the stone cells is to be thicker on one side than on 
the other, as is plainly shown. (3) represents the structure of the inner 
layer of the bark, showing bast fibers h cut across, and more of the so- 
called mucilaginous cells s of large size, which normally contain the 
ethereal or volatile oil. The starch granules (4) are contained in great 
abundance in the polygonal cells of the parenchyma of the intermediate 

♦ Twenty-second Annual Report Conn. Exp. Sta., 1898, pp. 204, 205. 



SPICES. 



3*9 



and inner bark layers. (6) represents a fragment of a bast fiber, which 
is often shown in cassia powder with connecting parenchyma. The 
stone-cells of the cork arc shown in plan view at (7). Very small, needle- 
like crystals of oxalate of calcium are occasionally to be seen if looked for 
carefully. They occur in the parenchyma cells of the inner and inter- 
mediate layers of the bark. 

The microscopical structure of Ceylon cinnamon much resembles 
that of cassia. Cassia starch grains measure from 0.0132 to 0.0222 mm., 




Fig. 77. — Powdered Cassia under the Microscope. X125. (After Moeller.) 



being considerably larger and more abundant that those of true cinnamon. 
As a rule the bast fibers of cassia are larger, but shorter, than those of 
cinnamon, and provided with thicker walls. 

Figs. 203 and 204, PI. XXI, show various phases of pure cassia bark as 
photographed from water-mounted specimens of the powder. Cassia 
starch somewhat resembles that of allspice, but it is not as a rule found 
in masses containing as many granules as does the allspice starch. Very 
commonly two or three of the starch granules are arranged together in 



33° FOOD INSPECTION AND ANALYSIS. 

such a manner that at first sight they appear to form a single large granule, 
but on more careful examination are seen to be two- and three-lobed, 
consisting of several smaller grains. Stone cells, which are very abundant 
in the powdered cassia, do not happen to be included to any extent in the 
photographed fields. Cassia stone cells are generally more oblong than 
those of allspice, and are more often brown in color, while the allspice 
stone cells are generally colorless. 

A distinctive feature of powdered cassia consists in the long, amber- 
colored wood fibers, some distributed in bundles, and others arranged 
singly. These are very clearly shown in Figs. 204 and 205. 

Yellow patches of cellular tissue with starch grains interspersed 
among them arc very abundant in the powder. 

Adulteration of Cinnamon and Cassia. — The U. S. standards for 
cassia and cinnamon are as follows: Total ash not to exceed 8%; sand 
not to exceed 2%. 

The adulterants most commonly found in these products are the 
cereal starches and ground foreign bark. Besides these, the writer has 
found, in the natural course of inspection in Massachusetts, leguminous 
starches, pea hulls, nutshells, turmeric, pepper, olive stones, ginger, 
mustard, and sawdust. 

Ground Bark of the Common Trees, especially that of the elm, 
resembles in physical appearance ground cassia, and is to be looked 
for as an adulterant. Fig. 265, PI. XXXVII, shows the appearance of 
ground elm bark. The fibers of cassia bark have starch granules as a 
rule interposed among them, while the foreign bark, usually of a much 
coarser texture, shows no starch connected with its structure. 

Fig. 206, PL XXII, shows a water-mounted specimen of adulterated 
cassia powder, chosen from samples purchased in the Massachusetts 
market. Nothing but the adulterant (a foreign bark) shows in the field. 
The tissue is loose and considerably coarser than that of cassia bark. 

PEPPER. 

Nature and Composition.- — Pepper is the dried berry of the pepper 
plant {Piper nigrum), a climbing shrub belonging to the family Pipe- 
racecR, native to the East Indies, but cultivated in many tropical countries. 
The height of the pepper plant is from twelve to twenty feet. When 
the fruit begins to turn red, it is gathered and then dried, by which process 
it turns black and shrivels up, forming the black peppercorns of com- 
merce. They are spherical single-seeded berries, about 5 mm. in diam- 



SPICES. 



33' 



cter, covered with a brownish-gray cpicarp, and having on the under 
side the remains of a short stem. At the toj) of the berry is an indistinct 
trace of a style, and of a lobed stigma. 

Varieties of black pepper are named from the localities in which they 
grow, as Singapore, Lampong, Sumatra, TeUichcry, Malabar, Acheen, 
Penang, Allepey, Trang, etc. 

White pepper is obtained by decorticating the fully ripened black 
peppercorns, or removing the dark skin. This is accomplished by mac- 
erating them in water to loosen the skin, which is then removed readily 
by drying and rubbing between the hands. White whole pepper grains 
are grayish white, and a trifle larger than the black pepper berries. They 
are nearly spherical in shape, and have a number of light-colored lines 
that, like meridians, run from top to bottom. 

Varieties of whole white natural pepper are obtained from Siam and 
Singapore, but are not frequently met with on the market. 

The pungent taste of pepper is due in great part to its essential oil, 
a hydrocarbon of the formula Ci„Hi„, present in amounts varying from 
0.5 to 1.7 per cent. Pepper oil contains phcllandrene and a tcrpcne. 

Another important constituent of pepper, contributing to its pun- 
gency, is the crystalline base piperin, C17H19NO3, insoluble in water, 
but soluble in ether, and in alcohol. Starch is present in pepper to a 
large extent. 

Burcker gives the following average percentage composition of black 
and white pepper: 











in 


^ 


i-a 




cS 






<U 









.S-M 



2 c: w 




< 




1 


is 


1 


« Sol 


CO 


III 
5ca 




4-S7 

1.80 


12.45 
6.08 


12.50 
13-56 


11.98 
II. 12 


1.36 
0.94 


6.85 
7. II 


42.90 
56.04 


7-39 

3-35 


White pepper 



Richardson's * analyses of three samples of whole black and two 
samples of whole white pepper, all pure, are as follows: 





Water. 


Ash. 


Volatile 
Oil. 


Piperin 

and 
Resin. 


Alcohol 
Extract. 


Starch. 


Black pepper: West coast 

Acheen 


8.91 
8.29 
9-83 
9-85 
10.60 


4.04 
4-7° 
.'■70 
1. 41 

1-34 


.70 
1.69 
1.60 

-57 
1.26 


7-29 
7.72 

7-15 
7.24 
7-76 


6.' 06 

5-74 

2-57 


36.52 

37-5° 
37-3° 
40.61 

43- 10 


Singapore 

White pepper: West coast 

Singapore 



* U. S. Dept. of Agric, Bur. of Chem., Bui. 13, part 2, p. 206. 



33* 



FOOD INSPECTION MND /tN/i LYSIS. 



Undeter- 
mined. 



Crude 
Fiber. 



Albumin- 
oids. 



Total 

NX 6.25. 



Total N. 



Black pepper: West coast, 
Acheen. . . 
Singapore . 

White pepper: West coast, 
Singapore . 



24.62 
13.64 
17.66 
23.28 
19-55 



10.23 
10.02 
10.02 

7-73 
4.20 



7.69 
10.38 
10.00 

9-31 
g.62 



9.81 
12.60 
12.08 
11.48 
11.90 



1-57 
2.02 

1-93 
1.83 
1.90 



Richardson gives the following variations in the constituents of 
pepper : 



pure 





Black. 


White. 


"Water 


8.0 to II. 

2-75 to 5-0 
.50 to 1.7s 
7.0 to 8.0 
32.0 1038.0 
8.0 to 1 1 . 
7.0 to 12.0 


8.0 to II. 
1.0 to 2.0 
.50 to 1.7s 
7.0 to 8.0 
40.0 to 44.0 
4. II to 8.0 
8.0 to 10. 


Ash 




Pinerin and resin 


Starch 


Crude fiber 







McGill's * analyses of six samples of whole black, and five samples 
of whole white pepper, all genuine, are thus summarized: 





Moisture, 
etc., Lost 
at loo" C. 


Ash. 






Soluble 
in Hot 
Water. 


Insoluble 
in Water. 


Total. 


Insoluble 
in Hydro- 
chloric 
Acid. 


Sand 
Expressed 
as Per 
Cent of 
Total 
Ash. 


Alcohol 
Extract. 


Black: Maximum 

Minimum 


14.10 
10.62 
12.03 
13.00 
11.30 
12.34 


2.64 
2.07 
2.41 
0.72 
0. 14 
0.54 


3.06 
1.46 
2.05 

3-04 
1.50 
2.46 


S.16 
3-98 
4-47 
3-65 
1.64 
3.00 


1.08 
.06 
0.36 
0.88 
0.26 

°-55 


21 
2 
8 

42 

9 
21 


9.06 
8.28 
8.71 
8.92 
7.00 
7-73 


White: Maximum 

Minimum 





Winton, Ogden, and Mitchell's f analyses of whole black pepper 
(fourteen samples, representing four varieties), whole white pepper (four- 
teen samples, some decorticated, and some of the Siam and Singapore 
varieties), and also of common pepper adulterants, are thus sum- 
marized : 



* Canada Inl. Rev. Dept. Bui. 20, 1890. 

t An. Rep. Conn. Exd. Sta.v i8q8, pp. 198-199. 



SPICES. 



333 



Black pepper: Maximum 

Minimum. 

Average. . . 
White pepper: Maximum 

Minimum. 

Average.. . 
Pepper shells: Maximum 

Minimum. 

Long pepper 

Buckwheat hulls 



tn 




Ash. 




Ether Extract. 


H 


J 


c 


3 

3 . 




Is 


s 





&-^' 


JK 



> 


■z" 


12 •9.') 


6.S2 


3-20 


1. 19 


1.60 


i°-37 


10.63 


3-°9 


I-7S 


0.00 


0.65 


6.86 


II .96 


4.76 


2-54 


0.47 


1. 14 


8.42 


14-47 


2.96 


0.80 


0.20 


0-95 


7-94 


12.72 


1-03 


0.28 


0.00 


0.49 


6.26 


13-47 


1-77 


0.47 


O.IO 


0-73 


6.91 


10.66 


II. 91 


3-20 


4-70 


I -06 


4-97 


10.52 


10.25 


2.28 


2-63 


0-68 


3-04 


9-47 


5-93 


4.20 


0.22 


1-55 


6.61 


7-63 


1.84 


1.24 


0.00 


0.07 


0.38 



o rt 



11.86 
8.47 
9.62 

8-SS 
7.19 
7.66 
6.30 
4.00 
8.67 
2.17 



Black pepper: Maximum 

Minimum. 

Average . . 
White pepper: Maximum 

Minimum. 

Average . . 
Pepper shells: Maximum 

Minimum. 

Long pepper 

Buckwheat hulls 



^ 1- 
4> S .: 
Jj >-^ 
<acu 

■- S " 



43-47 
28.15 

38-63 
64-92 
56-43 
59-17 
21.69 

11-43 
42.88 
20.51 






39.66 
22.05 

34-15 
63.60 

53-11 
56-47 
15-30 

2.30 
39-55 

1 .46 



18.25 

i°-75 

13.06 

4-25 

0-54 

3-14 

32-15 

23.27 

S-76 
43-76 



2z« 






13.81 
10.50 
13.06 
II .19 
10.44 
10.89 
14.19 
12.31 
12.25 
3.06 



Nitrogen. 



2-53 
2-03 
2.26 
2.13 

1-95 
2 -04 

2-36 
2. 12 
2.18 
0.49 



g"2 



0.40 
0.27 
0-33 
0-34 
0.26 
0.30 

0-15 
0.09 



VVinton and Mitchell's analyses of ground pepper, sold in labeled 
packages in Connecticut and pronounced unadulterated, are as follows: 





Ash. 


Non-vola- 
tile Ether 
Extract. 






Total. 


Insoluble 
Hydro- 
chloric Acid. 


Crude 
Fiber. 


Black, 36 samples: Maximum 


7.61 
3-90 
4.01 
1.09 


S-2I 


9-37 
6-54 

8.27 
4-07 


17.99 
7-64 
6.49 
0.43 




White, 12 samples: Maximum 







The following table summarizes the results of full analyses of pepper 
and pepper shells recently made by Doolittle: * 



* Mich. Dairy and Food Comm Bui. 94. 



334 



FOOD INSPECTION /IND yINyl LYSIS. 











Ash. 




No. of 
Samples. 


No. of 
Varieties. 


Mois- 
ture. 




















Total. 


Insoluble 
in HCl. 


Soluble in 
Water. 


45 


12 














II .96 


8.04* 


2-59* 


3-3 = 






8.09 


3-43 


0.05 


1.65 






9-54 


4-99 


0.58 


2-49 


















13-34 


4.28 


0.86 


1. 16 






8.04 


0.86 


0.05 


0.12 






9.87 


1.69 


0.19 


0-34 


3 
















10.13 


14-39 


5.92 


4-39 






8.43 


6.12 


0-45 


1.72 


4 
















II. 01 


28.81 


22.90 


4.66 






7.00 


7.82 


0.79 


1-53 



Starch by 
Diastase 
Method. 



Black pepper: 

Maximum. . . 

Minimum . . 

Average .... 
White pepper: 

Maximum . . 

Minimum . . 

Average 

Long pepper: 

Maximum. . 

Minimum. . 
Pepper shells: 

Maximum. . 

Minimum . . 



41-75 
25.09 
36.69 

63-55 
48.88 

54-37 

45-87 
28.43 

11.70 
9.28 



Black pepper: 

Maximum. . 

Minimum . . 

Average. . . . 
White pepper: 

Maximum. . 

Minimum . . 

Average. . . . 
Long pepper: 

Maximum. . 

Minimum . . 
Pepper shells: 

Maximum. . 

Minimum . . 



Ether Extract. 



Volatile. 



2.10 
0.85 
1.3b 

1.66 
0.78 
1. 17 

1. 01 
0.79 



0.89 



Non-vola- 
tile. 



10.44 
6.60 
7.67 

7.26 

5-65 
6.46 

7-53 
5-71 

4.67 
1-51 



Crude 
Fiber. 



18.89 
10.05 

II. 12 

7-65 
O.IO 

4-17 

10.01 

7.19 

28.22 
21.06 



Nitrogen. 



• Total. 



2.38 
1.86 



2.14 
1-85 
1.97 

2.04 
2-13 

1.82 
1.72 



In Non- 
volatile 
Ether 
Extract. 



Total N 
less N in 
non-vola- 
tile Ether 
Extract 
X6.25. 



0-45 
0.25 

°-3i 

0-34 
0:24 
0.30 

0.22 
0.18 

0.12 
0.02 



13.12 

9-25 
II .20 

II .56 

9.69 

10.44 

12.06 
"-37 

11.25 
10.00 



* Two samples of Acheen C pepper had a total ash of 8.00% and 8.04%, with "'ash insoluble in 
HCl" of 2.50% and 2.40% respectively. Eliminating these two samples, which were evidentlv 
abnormally high in sand and dirt, the highest total ash of the remaining 43 samples was 7.00%, 
while the highest ash insoluble in HCl was i.So%. 



Determination of Nitrogen in Black and White Pepper. — In making 
this determination, the earlier analysts employed the ordinary Kje'.dahl 
or Gunning method, but Winton, Ogden, and Mitchell have shown that 
these methods are inapplicable in the case of pepper, giving results much 
too low, on account of the piperin. The Gunning-Arnold t method 
has been found to be more serviceable and accurate. In accordance 
with this method i gram of the sample is mixed with a gram each of 
copper sulphate and red o.xide of mercury, about i6 grams of potassium 
t Zeits. anal. Chem., 31. 525. 



SPICES. 33S 

sulphate, and 25 cc. of sulphuric acid in a Kjeldahl flask, for both diges- 
tion and distillation, of about 600-cc. capacity. The heating is conducted 
in the usual manner, beginning with a gentle heat till the frothing ceases, 
and gradually increasing the temperature till the mixture boils. The 
boiling is continued for three or four hours, after which the flask is 
cooled, and to it are added 300 cc. of water, 50 cc. of potassium sulphide 
solution,* and enough of a saturated solution of sodium hydroxide to 
render the reaction alkaline. 

The flask is then connected to the condenser, and the distillation con- 
ducted as in the Gunning method (p. 61), using zinc dust to prevent 
bumping, receiving the distillate into standard acid, and titrating against 
standard alkali. 

Nitrogen Determination in the Ether Extract. — Ten grams- of the 
sample are extracted with absolute ether for twenty hours in a con- 
tinuous-extraction apparatus, the extract being collected in a tared Kjel- 
dahl extraction- and distillation-flask, the same as used in the preceding 
section. The ether is then evaporated ofT, the residue dried to constant 
weight at 110° C. and its weight ascertained. The nitrogen is then 
determined in the ether extract by the Gunning-Arnold method. 

Determination of Piperin.f — Fifty grams of the sample are thoroughly 
exhausted with hot alcohol, and the alcohol extract evaporated to dry- 
ness. The dry residue is then treated with a solution of potassium 
hydroxide, and washed upon a filter. The residue is washed several 
times with the caustic alkali, which dissolves the resinous matters, and 
afterwards with water. It is then dissolved in alcohol, from which crystals 
of crude piperin separate on evaporation. These are redissolved in 
alcohol, and precipitated by the addition of water. The crystalline pre- 
ci])itate is collected on a tared filter, washed with water, dried, and 
weighed. 

Piperin may be roughly estimated by multiplying the nitrogen in 
the ether extract by the factor 20.36. 

The amount of piperin varies considerably, ranging in black pepper 
from 4 to 9 per cent. 

Microscopical Characteristics of Ground Pepper.^ — Moeller's repre- 
sentation of powdered black pepper shows what should be looked for 
under the microscope with the best conditions (Fig. 78). The shell of 
the peppercorn, a cross-section of which is shown at (i), consists of the 

* Forty grams K^S in i liter of water. 

t ViUiers ct Collin, Substances Alimcntaires, p. 371. 



336 



FOOD INSPECTION AND ANALYSIS. 




epidermis, a, under which is a thin layer of brown parenchyma, c, 

while below this layer is shown the most characteristic portion of 

the pepper shell, viz.: the thickened, 
colored, stone cells, b. These are as a 
rule inclined to be rectangular rather 
than rounded. At d is shown a bit of 
the colorless parenchyma of the fruit 
itself. 

(2), (3), and (4) show a cross-section 
of the outer part of the berry, (2) 
representing the inner stone-cell layer, 
a single row of horseshoe-like cells, 
(3) the thin seed coat, and (4) the white 
perisperm, with its large cells. Here and 
there through the perisperm certain yellow 
contents are visible, consisting largely of 
resinous matter. A dark resin cell is 
shown at (4). The ethereal oil, starch, 
and piperin are found in this part of 
the berry. 
(5) shows in plan view the mostly rectangular stone cells of the 

pepper shell, resting upon the epidermis (6). Groups of stone cells 

are frequently thus found with portions of the epidermis. 

The inner rounded, or cup-shaped cells are shown in plan view at 

(7) and the seed skin at (8), masses of starch and separate starch granules 

are shown at (9), and crystals of piperin at (10). 

The bast -parenchyma of the pepper stem is shown at (11), 

pieces of which are commonly found in powdered pepper, and (12) 

shows a fragment of one of the many-celled hairs which grow on the 

stem. 

The rounded cup cells (7) are readily distinguished from the more 

rectangular stone cells (5). The walls of the cup cells are nearly always 

colorless, and the cells themselves empty.* 

A water-mounted specimen of finely ground, black pepper, when 

viewed microscopically, shows most of the elements above described, at 

least in fragmentary form, though, in the case of the coarser particles. 



Fig. 78. — Powdered Black Pepper 
under the Microscope. X 125. 
(After Moeller.) 



* The harder portions of the pepper, especially of the shell, are best examined by soak- 
ing for at least twenty-four hours in chloral hydrate, and mounting in this reagent on the 
slide. 



SPICES. 337 

by no means as clearly as by the use of chloral hydrate. Large polyg- 
onal masses of starch appear grouped as photographed in Fig. 256, PL 
XXXI\', if not rubbed out too fine under the cover-glass. Starch, in- 
deed, is the most conspicuous element of pepper, being distributed more 
or less evenly throughout the mass. The powder may, however, be so 
finely reduced by abrasion under the cover-glass as to break up these 
starch masses wholly or in part, so that the granules may appear in much 
smaller groups or even singly. Fig. 255 shows such a field under a 
higher magnification. The individual granules of pepper starch average 
0.003 ^'^^- ^^ diameter. 

Besides the starch, and next to it the most numerous, one finds in the 
water-mounted black-pepper specimen many of the dark -yellow, thick- 
walled stone cells, patches of the colored parenchyma, and epidermis of 
the shell. Other elements of the perisperm, besides the starch, are 
seen in fragments, such as bits of resin, small droplets of oil, pieces of 
stems, and occasionally the needle-shaped crystals of piperin. Some 
of the rounded, cup-shaped cells are also usually found. 

White pepper contains, of course, the same elements, but without 
the deeply colored stone cells and other characteristics of the shell, 
which has been removed from it. 

Adulteration of Pepper. — The following U. S. standards for pepper 
have been adopted: For white pepper, non- volatile ether extract should 
not be less than 6%; starch should not be less than 53% by the diastase 
method, nor less than 40% by direct inversion; total ash should not be 
more than 4%; ash insoluble in hydrochloric acid should not exceed 0.5%; 
crude fiber should not exceed 5%. One hundred parts of the non-volatile 
ether extract should contain not less than 4 parts of nitrogen. For black 
pepper, which should be free from added pepper shells, pepper dust, and 
other pepper by-products, non-volatile ether extract should not be less 
than 6%; starch by the diastase method should not be less than 22%, and 
by direct inversion should not be less than 28%; total ash should not 
exceed 7%; and crude fiber should not exceed 15%. One hundred parts 
of the non-volatile ether extract should contain not less than 3.25 parts of 
nitrogen. The adulterants used in ground pepper are many and varied. 

Pepper Shells, which have been removed from the white pepper of 
commerce, are not infrequently ground and added to the cheaper grades 
of black pepper. When a sample of black pepper is shown by the micro- 
scope to contain more shells in proportion to the other elements than 
could be possible in a ground whole berry, added shells are indicated- 



338 FOOD INSPECTION /1ND ANALYSIS. 

The analyst should, for comparison, grind in a mortar single berries of 
various grades, and familiarize himself with the appearn,nce of the ground 
powder under the microscope, when the maximum amount of shells 
possible under natural conditions are present, noting especially the appar- 
ent number of stone cells of the outer coating. The familiar title of P. D. 
(pepper dust) originally given to ground pepper shells, stems, and "sweep- 
ings " is now applied in the trade not only to almost any cheap and appro- 
priate material for admixture with pepper, but also, in a broader sense, 
to ground powder suitable as an adulterant for any spice. 

Ground Olive-stones constitute one of the most commonly found foreign 
materials used as an adulterant of pepper. The powder, sometimes 
called "poivrette," is \cry like white pepper in appearance, is wholly 
inert in taste, and thus forms an admirable adulterant. Wliile best 
detected by their characteristic appearance under the microscope, the 
presence of ground olive stones may be shown by color tests with certain 
chemical reagents. 

Pabst has adopted for this purpose a test first suggested by Wurster 
for the detection of wood pulp in paper. The reagent is prepared as 
follows: In a porcelain capsule lo grams of commercial dimethyl anihn 
are mixed with 20 grams of pure concentrated hydrochloric acid, and 
at least 100 grams of cracked ice are added. Then, while stirring, a 
solution of 8 grams of nitrite of soda in 100 cc. of water are added httle by 
little, and the mixture allowed to remain for half an hour, after which 
30 or 40 cc. of hydrochloric acid are added, and 20 grams of tin-foil. 
The reduction is allowed to go on for half an hour, heating on the water- 
bath, if necessary. The tin is then precipitated by granulated zinc, the 
liquid is filtered, and the filtrate neutralized with carbonate of potassium 
or sodium to the point of forming a precipitate, the precipitate being 
dissolved by a few drops of acetic acid. Finally the volume is made up 
with water to 2 liters, adding, before doing so, 3 or 4 cc. of a concentrated 
solution of sodium bisulphite, to prevent oxidation. The reagent thus 
prepared will keep for several years in a brown, tightly stoppered bottle. 

If a pinch of pepper, which contains ground olive stones, be heated 
gently with a little of the above reagent in a test-tube, the stone cells 
of the adulterant will be colored a bright red brown, and the colored 
particles will be seen to settle to the bottom of the tube, after shaking, 
more quickly than the rest of the powder. Or, if the whole is poured 
from the test-tube into a porcelain dish, the color is more marked. Pure 
pepper is not colored under this treatment with the reagent. 



SPICES. 339 

Jumeau uses for a color reagent 5 grams of iodine in 100 cc. of a mix- 
ture of equal parts of ether and alcohol. Enough of the finely ground 
pepper to be examined is placed in a porcelain capsule to cover the 
bottom of the dish, and sufficient iodine reagent is added to wet the entire 
mass, carefully avoiding excess. The thick paste is first mixed till homo- 
geneous, and then allowed to dry in the air, after which it is broken up 
by a pestle, and the powder examined, either under the microscope, or 
by the naked eye. With pure pepper, a more or less deep-brown color 
is produced uniformly through the powder, but if olive stones are present, 
particles of these are colored yellow. With the naked eye as small an 
admixture as 2% of oUve stones can thus be detected. 

A solution of anilin acetate colors olive stones yellowish brown, 
while pure pepper appears grayish, or white. 

Under the microscope olive stones are readily apparent, since the 
stone cells differ in size, form, and mode of grouping from those of pepper. 
Fig. 263, PI. XXXVI, is a photograph of a water-mounted specimen of 
olive stones. They are for the most part entirely devoid of color, being 
long and narrow. In shape and manner of grouping they much resemble 
cocoanut shells (p. 321), but are distinguished from the latter from their 
lack of color. 

Fig. 261 shows under low magnification a sample of pepper, bought 
on the market in Massachusetts, highly adulterated with olive stones. 
A large mass of the stone cells of the adulterant appears in the center of 
the field. Many of the stone cells are sho\\'n arranged end to end, so 
that what at first sight appear to be single, very long cells are in reality 
made up of several shorter ones. In ground olive stones one frequently 
finds, besides the stone cells, bits of the outer tegument of the seed, show- 
ing large cells with sinuous, rather thick walls; also bits of parenchyma, 
crossed frequently by fibro-vascular duct bundles. 

Buckwheat Middlings constitute a material much used as an adul- 
terant of pepper. The starch of buckwheat possesses the added advan- 
tage, from the point of view of the spice-grinder, that it somewhat 
resembles pepper starch in microscopical appearance, not only in the 
shape of the starch granules, but also in the manner of grouping into 
masses. Compare Figs. 128 and 129, Plates II and III, showing buck- 
wheat starch, with Figs. 255 and 256, PI. XXXIV, respectively, showing 
pepper starch made under similar conditions of magnification, etc. The 
two are readily distinguished by difference in size. The starch granules 
and masses are coarser in the case of buckwheat than of pepper. 



34° 



FOOD INSPECTION AND ANALYSIS. 



Fig. 260, PI. XXXV, shows a photograph of a pepper sample adulterated 
with buckwheat, masses of both starches appearing in the same field. 

Other Adulterants found in Alassachusetts samples of pepper have 
been wheat and corn products, nutshells, cayenne, charcoal, turmeric, rice, 
sand, and sawdust. 

Long Pepper, according to Enghsh analysts, has been used to a con- 
siderable extent as an adulterant. This is the fruit of the Chavica Rox- 
burghii, a wild plant growing in India on the banks of rivers. The fruit, 
as its name implies, is long and cylindrical, while of about the same diam- 
eter as the spherical true peppercorns. It is undoubtedly a form of 
pepper, in that the fruit contains the same ingredients as true pepper, 
\iz. : starch, resin, piperin, etc. Long pepper contains, as a rule, less 
than half the amount of piperin that true pepper does, and rather more 
starch than black pepper. Its taste is much less pungent than that of 
true pepper. 

From its method of growth, long pepper is found with considerable 
dirt and sand adhering to the outer surface of the dried grains. This 
is due to the fact that the fruit often trails on the ground, and in gather- 
ing it the natives are not particular about removing the adhering soil. 
The surface of the fruit grains being very rough and irregular, much 
of the dirt remains dried thereon. The presence of long pepper thus 
materially increases the ash. 

Long pepper possesses a ver}' disagreeable, but pecuUar odor, devel- 
oped more especially when sUghtly warmed. For this reason, if for 
no other, it is not an ideal adulterant, since pepper containing it would 
not be palatable with warm food. 

Brown gives the following analyses of samples of long pepper: 



Total 
Ash. 



8.91 
8.98 
9.61 



Sand and 
Ash Insol- 
uble in 
Hydrochlo- 
ric Acid. 



1.2 
I.I 

1-5 



Starch and 
Matters 
Converti- 
ble into 
Sugar. 



44.04 

49-34 
44.61 



Albumin- 
ous Matter 
Soluble in 
AlkaU. 



15-47 
17.42 

15-51 



Cellulose. 



iS-7 
10-5 
i°-37 



Alcoholic 
Extract. 



7-7 
7.6 

10-5 



Ether 
Extract. 



5-5 
4-9 
8.6 



Total 
Nitrogen. 



2.1 
2.0 
2-3 



According to Brown and Heisch, the granules of long pepper starch 
under the microscope are larger than those of true pepper, and more 
angular. Stokes,* however, finds no such marked difi'erence in the size 



* Analyst, XIII, p. 109. 



SPICES. 341 

of starch granules and his experience is shared by the writer. When 
the two specimens (long and true pepper) are viewed side by side in 
water mounts under the microscope, the average size of the long pepper- 
starch grains is a trifle larger than those of true pepper, though, unless 
compared directly, the difference is not readily apparent. Stokes sug- 
gests a method of distinguishing the two by polarized light. With crossed 
Nicols, so that a dark field is given, and with the specimen mounted 
in glycerin, true pepper starch shows an evenly dark appearance, using 
a low power, while with long pepper a "ghostly white" image is shown. 
Long pepper, when present in true pepper powder, may generally be 
rendered apparent by the development of the characteristic odor on 
heating. It may also be detected by spreading out particles of the pow- 
dered material on paper, and examining them with a magnifying-glass. 
Bits of fluffy fiber from the catkin of the long pepper will always be found 
in the ground powder, and will be apparent under the magnifying-glass. 



CAYENNE. 

Nature and Composition. — Cayenne pepper of commerce is the 
ground dried fruit pods of several species of Capsicum, a genus of the 
nightshade family (Solanacece), indigenous to the American tropics, 
but now cultivated in nearly all warm countries. The species furnishing 
the most common sources of Cayenne pepper are Capsicum annuum, Cap- 
sicum jrukscens, Capsicum jastigialum, Capsicum longum, and Capsicum 
haccatum. The kitchen garden variety of ordinary red pepper is for 
the most part the Capsicum annuum, of which there are over thirty 
varieties cultivated in the United States. The Cayenne and Chili vari- 
eties are most highly prized, because of their pungency. The fruits of 
these are somewhat long and slender. Other varieties are of larger size 
and milder. 

Paprika or Hungarian red pepper is a very mild variety of Capsicum 
annuum much prized on account of the intense red color of its pods. 
The powder is of a much deeper color than that of ordinary varieties 
of cayenne. 

The capsicum plant has sohtary flowers, with a iive-cleft corolla, and 
the fruit is of an elongated, conical form. The surface of the fresh fruit 
is smooth and very red, but it loses some of its brilliance in drj'ing, and 
becomes shriveled. The pericarp is thin and tough, and at its base is 
a five-lobed calyx, greenish brown in color, terminating in a thick stem. 



342 



FOOD INSPECTION AND /IN/ILYSIS. 



The fruit proper is divided into two or three cells, which are separate 
and distinct at the lower portion, but which unite and form one at the 
top. The cells inclose a large number of yellow, wrinkled, kidney- 
shaped seeds, containing a fleshy albumen, and a curved embr)'o. 

Cayenne contains a fixed, bland oil, found in both pod and seed, but 
more abundantly in the latter, considerable resinous and mucilaginous 
material, a red coloring matter confined to the pod, and the active principle 
capsicin, a crystalhne alkaloid, to which much of the pungency is due. 
The capsicin is present in both seeds and pod, but is more abundant in 
the latter, where it is dissolved in the oil. 

Capsicin may be isolated, according to Thresh, by extracting pow- 
dered cayenne with petroleum ether, mixing the red residue left on 
evaporating off the solvent with two or three times its weight of oil of 
almonds, and exhausting the mixture with alcohol. On evaporating 
the alcohol extract, the capsicin crystallizes out in narrow, thin plates, 
very soluble in alcohol, but insoluble in water. They volatilize at ioo°, 
and condense in small drops. 

The red coloring matter is soluble in ether, petroleum ether, carbon 
bisulphide, and chloroform, but sparingly soluble in alcohol. 

Richardson * gives the following data of analyses of two pure samples 
of cayenne: 





1.^ 


< 



•2 
E 


U 

lis 




c 
.S3 







£ 
'z. 


A 


2-35 

5-74 


9.06 

5-24 


0.12 

1-58 


26.99 
17.90 


16.88 
18.10 


13-13 
11.20 


41-47 
40.24 


100 
100 


2.10 


B 


1.70 





Maximum and minimum data of ash and non-volatile ether extract 
of fourteen samples of cayenne, sold in sealed packages in Connecticut, 
and analyzed by Winton and Mitchell are as follows if 





Ash. 


Non-volatile 
Ether Extract. 




7. If 
5.S8 


19.14 
15-59 







* U. S. Dept. of Agric, Div. of Chem., Bui. 13, p. 211. 
■f^ An. Rep. Conn. Exp. Sta., 1898, p. 175. 



SPICES. 



343 



Winton, Ogdcn, and Mitchell analyzed eight samples, representing 
three varieties of cayenne, with the following summarized results: 





Moisture. 


Ash. 


Ether Extract. 




Total 


Soluble in 
Water. 


Insoluble 
in HCl. 


Volatile. 


Non-vola- 
tile. 


Maximum 


7.08 
3-67 
5-73 


5-96 
5.08 

5-43 


4-93 
3-3° 
3-98 


0.23 
0.05 
0-I5 


2.57 

°-73 

1-35 


21.81 




17-17 
20. 15 








Alcohol 
Extract. 


Reducing 
Matters as 

Starch. 
Acid Con- 
version. 


Starch by 
Diastase 
Method. 


Crude 
Fiber. 


Nitrogen. 
X6.25. 


Total 
Nitrogen. 


Maximum 


27.61 
21.52 
24-35 


9-31 
7-15 
8.47 


1.46 
0.80 
1. 01 


24.91 
20-35 
22.35 


14.63 
13-31 
13-67 


2-34 
2-13 
2.18 




Average 







Microscopical Structure of Cayenne. — Fig. 79, from Moeller, shows 
the appearance under the microscope of various elements of powdered 
cayenne, (i) is a sectional view through the outer portion of the fruit 
shell or pod, showing the epidermis a, and beneath this the collenchyma 
layer b. The inner epidermis is shown at (2), with its cells thick- walled 
in places, and inclosing brilliant, red oil drops of coloring matter. (3) 
represents the outer and (4) and (5) the inner epidermis in plan view. 
In (5) the oil drops are more clearly shown. The outer epidermis of 
the variety known as Chillies is shown at (6). 

A cross-section through the seed shell is shown at (7), a being the 
epidermis of the seed, b the parenchyma layer directly beneath, and c 
the albumen of the endosperm. (8) shows in plan view the pecuhar 
seed epidermis, the appearance of which Moeller compares with that of 
tripe. At (9) is shown one of the isolated cells of the seed epidermis 
more highly magnified, while (10) shows the epidermis of the calyx. 

Figs. 211 and 212, PI. XXIII, show photomicrographs of powdered 
cayenne. In Fig. 211 is shown a large bit of the outer epidermis of the 
fruit pod, while in Fig. 212 appears a smaller portion of this same kind 
of epidermis, and next to this the tripe-Uke skin of the seed shell, with its 
striking markings suggestive of the convolutions of the intestines. Yellow 
or yellowish-red droplets of oily coloring matter are distributed through 
the field. Cayenne has no starch. 



344 



FOOD INSPECTION AND ANALYSIS. 



Adulteration of Cayenne. — The U. S. standards for cayenne are the 
following: Non- volatile ether extract should be not less than 15%; total 
ash should not exceed 6.5% ; ash insoluble in hydrochloric acid should 
not exceed 0.5%; starch by the diastase method should not exceed 



1.5%, and crude fiber should not exceed 2i 



The most common adulterants of cayenne are the starches of the 
cereal grains, corn and wheat. Ground pilot bread and crackers are 
especially common. Besides these the writer has found in the routine 




Fig. 79. — Powdered Cayenne under the Microscope. X125. (After Moeller.) 



examination of cayenne samples in Massachusetts, ginger, nutshells, 
turmeric, rice, gypsum, buckwheat, olive stones, mustard hulls, ground 
redwood, red ocher, and coal-tar dyes. Fig. 213, PL XXIV, shows a 
sample adulterated with wheat, com, and cocoanut shells. 

Mineral Adulterants, such as gypsum, and red ocher and other pigments, 
are all to be looked for in the ash by methods of qualitative analysis. 



SPICES. 345 

An abnormally high ash is suggestive of adulteration. According to 
Vedrodi, the ash of genuine cayenne should not exceed 5.96. The presence 
of red ocher is rendered apparent by the high content of iron. 

Salts of lead and mercury are rarely if ever now used for color. 

Grotind Redwood. — Numerous varieties of redwood arc commonly 
used to intensify the color of cayenne, especially when otherwise highly 
adulterated with colorless materials, such as the starches. The redwood 
is sometimes used alone, and sometimes in mixture with turmeric. Both 
redwood and turmeric are readily recognized under the microscope. 

Fig. 214, PI. XXIV, shows a cayenne sample adulterated with com 
starch and red sandalwood, a mass of the latter filling the center of the 
field. The wood fibers of the dyestuff, even when finely ground, are 
very striking under the microscope, showing a brick-red color. 

Detection of Coal-tar and Vegetable Colors. — Oil-soluble coal-tar 
dyes and vegetable colors may be tested for in cayenne by an adaptation 
of Martin's butter-color method, shaking the sample with a niixture of 
two volumes carbon bisulphide and fifteen volumes alcohol. The carbon 
bisulphide dissolves the oil and natural color of the cayenne, while the 
overlying alcohol layer would hold in solution many of the artificial 
coloring matters that may be employed. 

The natural color of cayenne is sparingly soluble in alcohol, but 
readily soluble in carbon bisulphide. The separated alcohol is examined 
for colors by methods given elsewhere. 

Szigeti* treats the suspected sample of cayenne with water acidified 
with acetic acid, and boils in this solution a bit of wool, which, if carotin 
or a coal-tar dye be present, is colored red. If the color is carotin, it will 
be removed from the wool by treatment with petroleum ether, or by heat- 
ing at 100° C. for some hours, but if a coal-tar dye, it will still remain fixed 
thereon. 

GINGER. 

Nature and Composition. — Ginger as a spice is the ground root- 
stock of the Zingiber officinale, an annual herb of the family of Zingi- 
beracem, growing to a height of from 3 to 4 feet. It is a native of India 
and China, but is cuUivated quite extensively in tropical America, Africa, 
and Australia. 

The root is dug when the plant is a year old, and when the stem has 

* Zeits. landw. Versuchs. Osterreich, 1902, 5, 1208, 1222. 



346 



FOOD INSPECTION AND ANALYSIS. 



withered. If the root, when freshly dug and scalded to prevent sprout- 
ing, is dried at once, it forms the so-called black ginger. When decorti- 
cated, it furnishes what is known in commerce as white ginger. The 
best variety of the latter is Jamaica ginger. The scraped root is some- 
times bleached to make it still whiter, or sprinkled with carbonate of 
Ume. 

In commerce whole or black ginger appears in fragments 4 to lo cm. 
long, and from 10 to 15 mm. in diameter. These usually have three or 
four various-sized, irregular branches, some short and thick, others 
elongated. The epidermis is gray or yellowish gray in color, more or 
less wrinkled, and beneath it is a reddish-brovra layer. The inner portion 
of the dried root is white or yellowish. The root is hard, and of a com- 
pact, horny structure. 

White or decorticated ginger appears in longer fragments, but of 
smaller diameter than the others, is less aromatic, and as a rule less highly 
prized. The principal part of the ginger of commerce comes from Cal- 
cutta. Preserved ginger root is prepared by boihng the root in water, 
and curing with sugar. Much of the preserved ginger comes from Canton. 

The distinguishing features of ginger are its large content of starch, 
its volatile oil, and its resinous matter. Inasmuch as the epidermis con- 
tains a large amount of pungent resin, it is easy to see how the peeled or 
decorticated variety is inferior. 

Oil of ginger is very aromatic, and of a greenish-yellow color. Its 
specific gravity ranges from 0.875 to 0.885. It is shghtly soluble in alco- 
hol. Of its composition little is known. 

Richardson's analyses in full of five samples of whole ginger-root are 
as follows: 





i 


< 


I-; 


C 

•g-g 


i 


■s.-s 




1!. . 


1 




9.60 

9.41 

10.49 

11.00 

10. II 


7.02 
3-39 
3-44 

4-54 
5-58 


2.27 
1.84 
2.03 
1.89 

2-54 


4-58 
4.07 
2.29 

3-04 
2.69 


49-34 
53-33 
50.58 
49-34 
50-67 


7-45 
2.05 

4-74 
1.70 
7-65 


6.30 
7.00 
10.85 
9.28 
9.10 


13-44 
18.91 

15-58 
19.21 
11.66 




Cochin 


I 12 




1.74 
1.48 
1.46 


Bleached Jamaica, London 

" " American 



Summaries of Winton, Ogden, and Mitchell's analyses of eighteen 
samples of pure ginger, as well as of two samples of e.xhausted ginger, 
are as follows: 



SPICES. 



347 







Ash. 





























o; 




3 


n 


3". 


i 




i 


f2 


S^ 


s.s 




11.72 


9-35 


4.09 


2.29 


3-53 


8.71 


3-fi 


1-73 


0.02 


0.20 


10.44 


5-27 


2.71 


0.44 


0.80 


10.61 


2.12 


0-S9 


0.18 




8.02 


5-05 


3-55 


1.50 





Ether Extract. 



cii 

0'3 



Ginger: Maximum 

Minimum 

Average 

Exhausted ginger from English ginger- 
ale works 

Exhausted ginger from extract works. . 



3-°9 
0.96 
1.97 

1. 61 
0.13 



5-42 
2.82 
4.10 

3.86 

0-54 






»« o - 



TO O 



5QS 









Ginger: Maximum 6.58 

Minimum 3-63 

Average 5.18 

Exhausted ginger from English gin- 
ger-ale works 4.88 

Exhausted ginger from extract works. 1.52 



62.42 
53-43 
57-45 

59.86 



60.31 
49-05 
54-53 

54-57 



S-50 
2-37 
3-91 

5-17 



9-75 
4.81 

7-74 
6.94 



17-55 
10.92 

13-42 

6.15 
16.42 



I-5S 
0.77 
1.23 

I. II 



McGill * records the analyses of ninety-eight samples of ground ginger 
as sold in the Canadian market. Of thirty-two of these, pronounced 
pure on analyses, the following is a summary: 





Moisture 
or Loss 
on Dry- 
ing at 
100°. 


Petro- 
leum- 
ether 
Extract. 


Cold- 
water 
Extract. 


Ash. 




Total. 


Soluble. 


Insoluble. 


Alkalin- 
ity of 
Soluble 
Ash as 
KsO. 


Maximum 


12.00 
9-5° 


6.13 
2.78 


15.48 
14.04 


7.84 
3-67 


3-15 
2.28 


3-99 -133 








" 



According to Vogl, the proportion of ginger ash varies quite widely 
according to the kind, but should never exceed S%. 

Exhausted Ginger and Methods of Detection. — There are two kinds 
of exhausted ginger commercially available for admixture with ground 
spice, as an adulterant. One is the product left after extraction with strong 
alcohol in the making of extract of Jamaica ginger, and the other the 
residue from extraction with either very dilute alcohol, or with water, 



' Dept. Inl. Rev. Canada Bui. 48, pp. 10, 11. 



348 



FOOD INSPECTION AND ANALYSIS. 



in the manufacture of ginger ale. Ground, exhausted ginger is rarely 
substituted wholly for the pure variety, since, from its lack of pungency, 
the sophistication would be too apparent. It is rather used to mix with 
the latter in varying proportions, and as an adulterant of other spices. 
Ginger that has been exhausted by extraction with alcohol has been 
deprived of most of its volatile oil, which is found in the "extract," while 
for the manufacture of ginger ale, a water extract, or at most a very dilute 
alcoholic extract is best adapted. Such a water extract does, as a matter 
of fact, remove much of the valued pungency, so that the residue, or 
exhausted ginger, is rather inert. 

Either the alcohol- or the water-extracted variety of exhausted ginger, 
when present in considerable amount, would be apparent, one by the 
alcohol and ether extract, and the other by the abnormally low cold- 
water extract, and water-soluble ash. 

Dyer and Gilhard * first called attention to the water-soluble ash as 
a reliable means of indicating exhausted ginger. Six samples of ginger 
of known purity were analyzed by them, their results being summarized 
as follows: 





Total Ash. 


Water- 
soluble 
Ash. 


Alcohol 

Extract, 

after Ether 

Extract. 


Pure ginger (6 samples) ; Highest 


4-1 
3-1 

3-8 

2-3 

I.I 

1.8 


3- 

1-9 

2.7 

0-5 
0.2 

0-3S 


3-8 




Average 


2.8 




0.8 




Average 


I . 2 







Allen and Moor f pointed out the value of the cold- water extract 
as a help in detecting exhausted ginger, especially when taken in con- 
nection with the soluble ash, showing that the presence of this adulterant 
is assured, when the soluble ash is as low as i%, and the cold-water extract 
is less than 8%. 

Determination of Cold-water Extract. — Winton, Ogden, and Mitchell's 
Method.X — Four grams of the ground sample are placed in a 200-cc. 
graduated flask, and the latter is filled to the mark with water, and shaken 
at half-hour intervals during eight hours, after which it is allowed to 

* Analyst, XVIII (i8g3), p. 197. 

t Analyst, XIX (1894), p. 194. 

X U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 59. 



SPICES. 



349 



Stand at rest for sixteen hours in addition. The contents are then filtered, 
and 50 cc. of the filtrate evaporated to dryness in a platinum dish. It 
is then dried at 100° to constant weight and weighed. 

Microscopical Structure of Ground Ginger. — Fig. 80, from Moeller, 
shows elements of ginger root, from which the epidermis has not been 




Fig. So. — Powdered Ginger under the Microscope. X12S. (After Moeller.) 



removed. A bit of the large-celled cork (or dead protective tissue of 
the epidermis) is shown in plan view at (i); at (2) is shown in cross- 
section the parenchyma in which the starch is contained, h being an oil- 
cell; (3) shows the parenchyma in longitudinal section, with bast fibers. 
Fragments of spiral ducts are shown at (4), and starch grains at (5). (6) 
is a cross-section in the extreme interior of the root. 

The most prominent feature of powdered ginger is the starch grains 
(5), which Moeller compares in shape to tied sacks. 

Fig. 228, PI. XXVII, is a photomicrograph of pure, ground ginger, 
mounted in water, showing the starch grains inclosed in the cells of the 
parenchyma. Fig. 231 shows the starch grains alone. The granules of 
■ginger starch are ellipsoidal, and as a rule very clear and transparent, 
being for the most part entirely devoid of either hila or concentric rings. 



35° FOOD INSPECTION AND ANALYSIS. 

Occasionally granules are to be found, however, with faint concentric 
markings, and even with an apparent hilum. The characteristic form of 
the ginger starch granule is more or less egg-shaped, with a small protu- 
berance near one end. This protuberance serves to readily distinguish 
the starch granules of ginger from those of wheat, with which ginger 
is frequently adulterated. While wheat granules are of various sizes, 
the grains of ginger starch are as a rule much more uniform. 

Adulteration of Ginger. — U. S. standard ginger should meet the follow- 
ing requirements: Starch by the diastase method should not be less than 
42%, and by the acid-conversion method should not be less than 46%; 
crude fiber should not exceed 8%; total ash should not exceed 8%; 
lime should not exceed 1%; ash insoluble in hydrochloric acid should 
not exceed 3%. 

Besides exhausted ginger, the most common adulterants found in 
powdered ginger are turmeric, wheat, corn, rice, and sawdust. Sawdust 
of soft wood is a not uncommon adulterant, and care should be taken 
to distinguish between the wood fiber natural to the ginger root, and that 
of the foreign variety. A careful study should be made of finely ground, 
soft-wood sawdust, with its long spindle cells and lateral pores, as shown 
in Fig. 266, PI. XXXYII, and the wood fiber of ihe genuine ginger root. 
A large admixture of sawdust would materially increase the percentage 
of crude fiber. 

Fig. 234, PL XXIX, shows a sample of ginger adulterated with com 
and wheat. Fig. 232 shows a mass of wheat bran in an adulterated 
sample. 

Fig. 233 shows ginger adulterated with turmeric* 

TURMERIC. 

Nature and Composition. — Turmeric, while largely used as an adul- 
terant of other spices (especially of ginger and mustard), possesses some 
value as a condiment in itself, forming, for instance, the chief ingredient 
of curry powder.f Turmeric (Curcuma longa) belongs to the same 
family (Zlngiberacea) as ginger, having a perennial rootstock, and an 
annual stem. It is a native of the East Indies and Cochin-China. Its 
chief ingredients are starch, a volatile oil, a yellow coloring matter (cur- 
cumin), cellulose, and gum. 

* This photomicrograph is very disappointing, in that it fails to show the intense yellow 
of the central mass of turmeric. 

t Curry powder consists of a mixture of turmeric, cayenne, and various pungent spices. 



SPICES. 



351 



Curcumin (CijHj^OJ is insoluble in cold water, but readily soluble 
in alcohol. It is extracted from powdered turmeric by boiling the latter 
with water, filtering, and extracting the residue with boihng alcohol. 
The alcoholic solution is filtered, evaporated, and the residue extracted 
with ether. The ether extract contains the curcumin, together with a 
small amount of volatile oil. 

Curcuma oil is an orange-yellow, slightly fluorescent liquid, its specific 
gravity being 0.942. 

The following analyses of turmeric were made in the writer's labo- 
ratory : 



Variety. 



China. . 
Pubna. . 
AUeppi. 

Average 



Mois- 
ture. 



Total 
Ash. 



9-03 
9.08 
8.07 

8-73 



6.72 

8.52 
5-99 

7-07 



Ash I Ash 
Soluble ; Insoluble 
in Water. in HCl. 



5.20 
6. 14 
4-74 

5-36 



Total 
Nitrogen, 



1-73 
0.97 

1.56 
1.42 



Protein, 
NX6.2S. 



Total 

Ether 

Extract. 



10. »I 
6.06 

9-75 



10.86 
12.01 
10.66 

II. 17 



Variety. 



Volatile 

Ether 
Extract. 



Non-vol- 






atile 


Alcohol 


Crude 


Ether 


Extract. 


Fiber. 


Extract. 






8.84 


g.22 


4-45 


7.60 


7.28 


5-84 


7-51 


4-37 


5-83 


7. 98 


6.96 


S-37 



Reducing 
Matter by 
Acid Con- 
version . as 
Starch. 



Starch by 
Diastase 
Method. 



China. . 

Pubna. 

Alleppi. 



Average . 



2.01 
4.42 
3 



16 



3-19 



48.69 
50.08 
5°-44 

49-73 



40.05 
29.56 
33-03 

34-21 



Microscopical Structure of Turmeric. — Moeller's representation of 
characteristics of powdered turmeric is reproduced in Fig. 81. The 
epidermis is shown at (i) with one of the numerous, one-celled hairs that 
grow from it, also the scar left after one of the hairs has been removed ; 
(2) shows in plan view the cork immediately under the epidermis. The 
tender-celled parenchyma is shown in cross-section at (3), and in longi- 
tudinal section at (4). In some of the cells of the parenchyma are found 
dark-yellow lumps of resin {h), and vascular ducts {g), but by far the most 
numerous and striking contents of the parenchyma-cells are the bright- 
yellow masses of "paste balls" (3a) and the starch granules, one of 
which is shown in (3). See also Plate XIII. The starch grains in the 
water-mounted powder show under the microscope in masses, usually of 
a deep-yellow color, unless very finely rubbed out, when they appear for 
the most part in fragments. 



352 



FOOD INSPECTION AND ANALYSIS. 



The whole starch granule appears somewhat in the form of a clam- 
shell, with very distinct markings. WTien fragments of the starch granules 
are carefully examined, these distinct markings are so strongly charac- 
teristic, even in the smallest pieces commonly found in the powdered 
sample, as to nearly always serve to identify them. See Fig. 171, 
PI. XIII. 

Turmeric as an Adulterant. — Turmeric is a material especially adapted 
by its deep-yellow color to intensify mustard and ginger, especially when 




Fig. 81. — Powdered Turmeric under the Microscope. X125. (After Moellor.) 



these spices are adulterated with the lighter-colored cereal starches, hence 
it is very commonly found in these spices, both with and without other 
aduherants. 

It is also frequently used in small quantities in adulterated cayenne 
mace, and various spices, to counteract the colors of other dyestuffs, 
such as ground redwood, which in itself would sometimes be too intense 
if used alone. 



SPICES. 353 

Turmeric, when present to any marked extent in a powdered spice, 
may be detected chemically, by extracting the material with alcohol, 
pouring off the latter, and soaking in it a piece of filter-paper. Tur- 
meric, if present, will stain the latter yellow, turning red with alkali, espe- 
cially apparent after drying. Soak the yellow paper in a solution of borax, 
acidulated shghtly with hydrochloric acid. When dry, a rose-red color 
will indicate turmeric, turning dark olive when dilute alkali is applied. 

MUSTARD. 

Nature and Composition. — Mustard is the seed of the mustard plant, 
an annual belonging to the family CrucijercB, and to the genus Sinapis, 
or Brassica, as it is sometimes called. The plant is an herb, native 
throughout Europe, and cultivated extensively in the United States. It 
grows to a height of from 3 to 6 feet, having yellow flowers and lyrate 
leaves. 

Two varieties commonly used are Brassica or {Sinapis) alba, white 
mustard, and Brassica (or Sinapis) nigra, black mustard, the ground 
spice being as a rule a mixture of the two. In the trade these varieties 
are known as brown and yellow mustard respectively. The seeds of 
both varieties are globular, those of the black mustard being small, and 
of a dark-brown color on the outside and yellow within. White mustard 
seeds are considerably larger than the black, being pale yellow in color 
on the outside. 

The surface of the black nmstard seeds is reticular, and full of 
small depressions, while the white variety is much smoother. There are 
several layers forming the husk of the seed of both varieties, and within 
the husk is the yellowish-colored kernel or embryo, with two cotyledons. 

Both black and white mustard contain from 31 to 37% of fixed 
oil, a soluble ferment known as myrosin, and a sulphocyanate of 
sinapin. Mustard seeds contain no starch, and very little volatile oil 
as such. Black mustard seed contains sinigrin, or myronate of potash 
(not found in the white seed), which, when moistened with water, forms 
by hydrolysis the volatile oil of black mustard, otherwise known as allyl 
isothiocyanate, in accordance with the following equation: 

KCioHieNSjO.-f H,0 = CeHjPe + CjH.CNS -f KHSO,. 

Potassium Glucose Mustard Potassium 

myronate oil bisulphate 

Mustard Oil (volatile) is a colorless, or slightly yellow, highly refrac- 
tive liquid of a very strong odor, and capable of blistering the skin when 



354 FOOD INSPECTION AND ANALYSIS. 

brought in contact with it. It is optically inactive. Its specific gravity 
varies between 1.016 and 1.030. It boils between 148° and 156°. It 
turns reddish brown by exposure to light. 

Volatile oil of black mustard forms thiosinamine with ammonia, as 
follows: 

C3H5CNS +NH3= CS.NH2.NH.C3H5. 

Thiosinamine is soluble in hot water, from which it crystallizes in 
tufts of monoclinic crystals, having a melting-point of 74° C. It is pre- 
cipitated by silver nitrate, mercuric chloride, and Mayer's solution. 

White mustard differs from the black in containing a sulphur com- 
pound, sinalhin, C30H42N2S2O15. This is a glucoside. Sinalbin by hy- 
drolysis forms an oil of white mustard, in a somewhat similar manner 
to the potassium myronate of black mustard, and according to the follow- 
ing equation: 

C3„H„N2S20.3+ H2O = C,H,ONCS -fCeHi^O^+CeH^^NO^HSO,. 

Sinalbin Sinalbin Glucose Sinapin acid 

mustard oil sulphate 

Sinalhin Mustard Oil cannot be obtained by the distillation of white 
mustard, being sparingly volatile with steam. 

Sinalbin mustard oil somewhat resembles that from black mustard, 
being quite as pungent, but less strong in odor when cold. It is soluble 
in dilute alkaU. 

Fixed oil of mustard is a bland, tasteless, and nearly odorless oil, its 
specific gravity at 15° varying between the hmits of 0.914 to 0.918. It 
is said to be used to some extent as an adulterant of table oils, being 
separated by pressure from the crushed mustard seeds before the latter 
are ground into "flour." The chief use of mustard oil is in mixture 
with other oils as an illuminant. 

Preparation. — In the process of preparing the ground spice com- 
monly known as mustard "flour," the seeds are first crushed and sepa- 
rated by winnowing from the hulls, the latter being incapable of the fine 
grinding necessary to produce a smooth flour. The yellow hulls are, 
however, found in the cheaper grades of ground mustard, and both 
varieties of hull are frequently used in the wet mustard preparations, 
sold in bottled form. In order to produce an even, dry powder, free from 
lumps, it is necessary to remove a large portion of the fLxed oil, which 
is indeed of no value in the final product, and this is done by subjecting 
the crushed material to hydrauhc pressure, during which process the 



SPICES. 



355 



mustard is molded together into thin, hard plates, called "mustard 
cake." This is then broken up and reduced to fine powder by pounding. 
Richardson's* analyses of whole-seed flour, prepared by himself 
without the removal of the fixed oil, are as follows: 



u 










x 


^ 


< 


5-57 


4.29 


3-33 


5-23 


b.i7 


4-99 


4.S3 


5-96 


4. II 


4.88 


3-" 


4.07 


4.62 


5-61 












X. 


<uS 


E . 




S 


Cft, 


i3 


•s.s 


to 


(J 


<; 


p 


.00 


5-40 


28.88 


21.33 


.00 


9 -OS 


25-56 


20.16 


.00 


9-5° 


23-44 


27-23 


.00 


8.50 


31-13 


16.35 


.00 


16.18 


24.69 


12.16 


.00 


6. go 


3°-2S 


22. 10 


.00 


10.84 


25.88 


18.87 



White seed 

White flour 

Seed husk 

California yellow, 
California brown, 
English yellow . . 
Trieste brown. .. 



-97 
1.84 

•55 


33- 
34- 
28. 


1.27 

1-35 
2.06 


31- 
36- 
31- 


-63 


39- 



-56 
-83 

.12 
.96 
-63 
-51 

-55 



4.62 
4.09 

3-75 
4.98 

3-95 

4.84 

4.14 



Winton and Mitchell made no full analyses of mustard seed of known 
purity, but the following is a summary of analyses of 18 samples of com- 
mercial mustards, sold in packages in Connecticut, and not found to be 
adulterated: 



Total 
Ash. 



Ether Extract. 



Volatile. 



Non-vol- 
atilc. 



Reducing 




Matters 


Starch 


bv Acid 


by 


Conver- 


Diastase 


sion, as 


Method. 


Starch. 




6.12 


2.08 


1-85 


0.28 


4-33 


1.07 



Crude 
Fiber. 



i Nitrogen 
X6.as. 



Maximum 
Minimum 
Average . . 



7-35 
4.81 

5-99 



1.90 
0.00 
0.56 



28.10 
17.14 
20.61 



4-87 
1.58 
2.58 



43-56 
35.63 
39-57 



The following analyses of 5 samples of mustard flour, 6 samples of 
mustard hulls, and 6 samples of whole mustard, were made in the author's 
laboratory in 1903: 



* U. S. Dept. of Agric, Div. of Chem., Bui. 13, part 2. 



356 



FOOD INSPECTION AND /IN A LYSIS. 





•asBis 1 
-BiQ Aq sja^ 
-^Bjv a.^np3>j 1 




M inO t^ O -^ 


■t 


(^O &©> t-0« in 
►-0 0-00*^1-0 




t 

N 




i 

c 

Q 

O 




f^f^f^WWMM« 




■uotsjaAuo3 
piay Aq sjal 
-Vbpi a.onpa-a 




f* CO i«OC 'O »fl O »t 

ui f^ Oi >o r^ 0> '^■O 





"^ 'TOO "J- " ^X O 
C -t t O r~oO t 


00 




in%o t^ O f-oO r^ C 


tri^i^Ttiriei-^-^ 










•jaqij apnJ3 




■*CO ". M »*■ O O 

"T^'t-ao o>« 


oo 


"0 "t ".O -^ too O 

00 N U-, f^ .-i r^ „ «) 


o 

00 




•tfOfOf^Wf^N f> 


r* t- t- r- r-CO 00 




"Hsy iBiox 




■too « uioC NO tn 


o 


M) w w « ■* «aOOO 
w O OO O O M f- 


CO 

o 




r->0 r- r- "tO O "O 


r-OO O r-OOO 




■ua3 

-OJ^lM IBIOJ, 


t-O — 00 O O O Oi 

W f^O O « O •- o 


f^O NCOO "to "t 
00 O O u^O -^ t t^ 


■t 
■t 


OO-^OO-O-OO 
W t- ui t- in O r^oD 


o 
o 




ooc^c^O'C^c^c^ ©• 


t^r- t~ r-O O t^O 




-xa loiiooiv 




C"0 t>o>-i/^« 
00 «rt r- 1^00 "1 ■* -■ 




t 


Tf "-, in 0> IN -C f^ 

in <roo oo o o 


00 

t 




N-oaoaoo o- 


■t fO rn -t ^m 




•asBisBiQ Aq 
sjaiiBjq Supnpa-a 


t-.WMfONO>- « 




o 


o 

►1 


l-l- "^OO O- ■- "5 


00 

t 


c 




M - « - M « 


u 


-UOTS 

-J3AU03 pioy Aq 


OCOOO Tj-M t-O CO 


O lOOO O O «« <- 
OO O^O ©.fO-t 


o 
o. 

o 


■* 
f^ 


TT Tf in^o woo 
O ■- fO O "to fO 


o 

00 




■- ^ lo r^-O lo to «0 


O r- O O 00 O » 


■s-P 


uaqiji aptuo 


N W TtOGO « O '^ 


"t « O &O0 •i^ O. 
OfO « "to ©■ N 

o >- — O t-O CC 1- 


o 


■t 


« O 1- ro inoo 1- 

N (OOO u-1 O W 't 


t 
o 

m 


fixed oil remov 
inner seed adhe 
oil and hulls. 


f^N«MMMN « 


Tj- ■,)• .^o "t <nio 


•IIO an^^oA 


oor-O-w'-' ■ -Of^vi 

0.^0 O O • ■ • ■ MOO o 

f^'J-'^'O'*" wmp» 




o 


OOO O o o • 




« N o o o • 


•ua3ojiiij.i Ib;ox 




O."tt-.«,NOOO 
OOOOOWOOm 




O 
4 


O C O N^o N r- 

■t N O iH 0.t-■t 


t 
t 


\0 O t^'C r*0 O "O 


■t -t m ■* r^ -* -t 




•IDBj^lxg loqoDtv 


«wcOt^t-COOi O 


f u^QO r^O — t^ "1 
^"t"t« oooco o 


o 


o 


OOO moo i-i M O. 
« 0*r~ 0"0 -* N 


o 


UlO-NTj-O'N N 


-for- ■^'O'O-O 


giig 




O '100 O "-. "o O O 


OOiOMOOt^MO 
o O « r^O r^O O 


o 
o 

oo 


00 

to 


o c o -r >^. "t IT) 

roo -00 to m 


c-O 




r^O-OCQN»oO. 00 


ino t- t-co 00 
en (O w c: « M « 


-xg J3qiia sin^IOA 


OOOOOOO O 


oooooooo 

O o 6 


o 
d 


ooooooo *• 
ooooooo • 




ooooooo o 


rt S ft 


-xg jama F^oX 


O "too ©-"liO o o 


ooirtw00r--0. 
fO O c* r-O f"0 o 


o 
o 

oo 


OC 


o o o -r "n ■-T f^ 

mo -00 to VI 


ro 


i-o«ooNmo 00 

MNMMMNtH n 


ino r- O i-OOoO 

rOrO N m f* W W 


1 i* 


"DH 
ut ajqupsui i^sy 




mNmOwOOO 


M 


N 


M M-O f^O N »- 
W N lO t^ M t fO 


fO 






•llSy 9iqt\|OS-J31Bj\i 


r~ "^ O CM« 'T* O O 


»rt-0 M *" M 00 O VI 
O « M ro o-r~co Oi 


o 


o 


t to t-^ m »no 


O 
m 


•g s § 

S <" 

S. H O 

* 4- +♦ 






■Hsy iBiox 


00 O U-' "t f^ OO "" 
U-, O N w t'-'O o o 


o -t t"- ""'O >no o 
lo-t-t-t't-t-r-t 


o 

■t 


o 


t "■< -t f^ t- in o 

00 O "000 r^ O f*l 


« 

t 


Ift'fl-lrtln'^'if* w 


rn ro 1 1 t t t 




•ajn^sioK 


irn*l O "1 r- C^cO O 


r^ r- loO O M O m 
OOO t^-fT- tfO 

-oco t^O m OOO r* 


oo 

"t 


oo 
00 


OOO O «"v fn M r- 
t -O O too "t 


o 




xn r~ C t^ r- irtvO -O 


OOO »no OO 








Mustard "flour" as pre- 
pared commercially: * 

English brown 

California brown 


Av. of brown flours. . 

German yellow 

California yellow 

Av. of yellow flours. . 
Average of all varieties 

nfflnnr 


Mustard hulls as removed 

in preparation of flour: t 

English brnwn 


i 

1 

> 

2 


c 
Z 


o ^ & 

36 


Average of all samples 

of hulls 

Whole ground mustard 
seeds, t 


California brown 

Av. of brown seeds. 
German yellow 


(A 

wo 


S ; 
>< : 

< 





SPICES. 357 

Piesse and Stansell give the following composition of mustard ash: 





White Seeds. 


Brown Seeds. 


Yorkshire. 


Cambridge. 


Cambridge. 


Potash 


2I.2g 
0.18 

13-46 
8.17 
1. 18 
7.06 

O.II 

32-74 

1. 00 

1.82 
12.82 


18. 88 
0.21 

9-34 
10.49 

i-°3 
7.16 
0.12 

35 -OO 
1. 12 

1-95 
15-14 


21 .41 

0-35 

13-57 

10.04 

1.06 

5-56 

0-15 
37.20 
1. 41 
1-38 
7-57 


Soda 




Magnesia 




Sulphuric acid 


Chlorine 






Sand 






99-85 


100.48 


99.70 



Determination of Myronate of Potassium and Sinapin Sulphocyanate.* 

— Extract at least 50 grams of the powdered material with several por- 
tions of a mi.Kture of equal parts of water and alcohol, digesting with the 
aid of heat in a flask with a return-flow condenser. Evaporate the 
alcoholic extract in a tared dish to dryness, and heat at 105° to constant 
weight. After weighing, incinerate the residue at a temperature suf- 
ficiently high to transform to the neutral sulphate the potassium bisulphate 
resulting from the decomposition of the myronate. The weight of 
myronate of potassium is obtained by multiplying the weight of neutral 
sulphate (the final ash) by the factor 4.77. This, deducted from the 
total weight of the dried alcoholic residue as above, gives that of the 
sulphocyanate of sinapin. 

Determination of Mustard Oil in Mustard Flour. — Roeser's MctJiod.-\ 
— Mix 5 grams of the sample with 60 cc. of water and 15 cc. of 60% alcohol, 
and let stand for two hours. Distil into a flask containing 10 cc. of 
ammonia, and, after about two-thirds of the solution have been distilled 
off, mix the ammoniacal distillate with 10 cc. of tenth-normal silver 
nitrate solution, and allow the mixture to stand for twenty-four hours, 
after which make up with water to 100 cc. Filter, and treat 50 cc. of 
the filtrate with 5 cc. of tenth-normal potassium cyanide solution. Titrate 
the excess of cyanide with the tenth-normal silver nitrate, using as an 
indicator a 5% solution of potassium iodide, made slightly ammoniacal. 

* Girard et Dupree Analyse des Matieres Alimentaires, p. 678. 
f Abs. Analyst, XXVII, 1902, p. 197. 



358 



FOOD INSPECTION AND ANALYSIS. 



The percentage of mustard oil present is found by multiply- 
ing by 2 the number of cubic centimeters of silver nitrate solution 
taken up by the oil, and multiplying this product by the factor 

0-3I37- 

Microscopical Characteristics of Powdered Mustard. — The principal 

features of powdered black mustard arc represented in Fig. 82. The 

seed shell or hull is shown in cross-section 
at (i), a being the polygonal-celled epi- 
dermis, h a layer of palisade-shaped cells, 
and c a thin pigment layer, the brown 
coloring matter of which is colored blue by 
iron salts; d is the glutinous layer and ob- 
scure parenchyma, and e the small-celled 
tissue of the cotyledons, containing fixed oil 
and albumen. 

(2) shows in plan view the various 
layers of the seed shell, the letters of 
reference corresponding to those of (i). 

(3) shows in plan view a bit of the 
extreme outer mucilaginous layer of the seed- 
hull. 

Fig. 247, PI XXXII, shows the ap- 
pearance in water-mount of pure ground 
mustard. This is a photomicrograph of the ground hulled seed with- 
out the extraction of the oil, and should not be taken as a standard 
for commercial mustard "flour," from which, as a rule, a large por- 
tion of the oil has been removed. The cellular tissue of the mustard 
shows in the form of granular masses of loose, fine gray texture; the 
globular bodies are oil drops. Here and there through the field of 
ordinary ground mustard are to be seen patches of the yellowish layer 
of the seed skin of the brown mustard, a mass of which is shown in 
Fig. 248, with dark-brown spots distributed regularly through h. This 
is the layer shown at (2) b, Fig. 82. The hull of the yellow seed, also 
common in powdered mustard, is similar in appearance, having dark- 
brown spots, but with a nearly colorless or gray background, instead 
of yellow. 

Patches of the outer hull layer represented by (3) in Fig. 82 are also 
very common in the commercial mustard flour. Mustard contains no 
starch. 




Fig. 82. — Powdered Mustard 
under the Microscope. X125. 
(After Moeller.) 



SPICES. 359 

Adulteration of Mustard. — U. S. standards for mustard are as follows : 
Starch, by diastase method, should not exceed 2.5% and total ash should 
not exceed 8%. 

It is difficult to draw the line between the amount of mustard hulls 
which may naturally occur in ground mustard, and the excess amount 
which is sometimes added as an adulterant. Samples in which the 
patches of hulls predominate in number over the regular cellular tissue 
of the seed, as seen under the microscope, are undoubtedly adulterated 
by the fraudulent admixture of ground hulls, that have been separated 
out from the crushed mustard seeds intended for higher grades. Samples 
of mustard flour thus adulterated are common.* 

In determining starch in mustard, it should be borne in mind that 
mustard hulls have considerable reducing matter by the diastase process. 

The most common adulterants of mustard, other than excess of hulls, 
are wheat, turmeric, millet and other weed seed, and rice. Yellow, oil- 
soluble azo-dyes are also employed. 

Other adulterants found in Massachusetts have been potato starch, 
cayenne, corn, and gypsum or "terra alba" (the latter being found in 
one instance to the extent of 21%). 

Fig. 250, PI. XXXIII, shows a sample of mustard adulterated with 
wheat bran. Very little besides the adulterant appears in this field. 

The common practice of adulterating mustard with wheat is an out- 
growth of the old notion that a certain amount of wheat flour was neces- 
sary' to prevent lumping. 

Samples of cheaper mustard flour are occasionally found to contain 
small amounts of wheat and foreign starch, apparently of accidental occur- 
rence. This is undoubtedly due to the fact that in some localities wild 
mustard often grows in the wheat-fields, so that after the wheat crop has 
been harvested, the mustard is gathered and sold. Such mustard seed 
would naturally contain varying admixtures of wheat, and sometimes seeds 
of various weeds, which it would not be profitable to separate out, even 

* It is claimed by some manufacturers that the hulls thus removed are not used as an 
adulterant of cheaper mustard flours, in view of the fact that it is diiEcult or impossible to 
grind them finely enough, but that they are used up in the manufacture of compound mus- 
tard pastes. A sample of ground mustard was recently found by the writer, in which it 
was noticed that a large number of yellow lumps were distributed through it. These lumps 
were picked out, transferred to the microscope slide, and crushed and rubbed out under 
the cover-glass. Examined under the microscope, they were found to consist entirely of 
a mixture of mustard hulls and turmeric, which would seem to show that hulls were present 
in this case as an adulterant. 



360 FOOD INSPECTION AND ANALYSIS. 

if it were possible to do so. Such contaminated mustard enters into the 
manufacture of the cheapest grades of flour only. 

Fig. 249, PI. XXXIII, shows the flour of the Dakota brown mustard, 
which is qne of the most common of these wild varieties. 

Detection of Coloring Matter.* — Turmeric is best detected by the 
microscope (see pp. 351 and 352). Oil-soluble coal-tar dyes should be 
tested for as in the case of cayenne. 



NUTMEG AND MACE. 

Nature and Composition. — Both nutmeg and mace occur in the fruit 
of several varieties of trees of the genus Myristica, especially of the Myri- 
stica jragrans or Myristica nioschata, belonging to the family Myrisli- 
cacecE. The nutmeg tree is a native of the Malay archipelago, and grows 
from 20 to 30 feet high, somewhat resembling the orange tree in appear- 
ance. It does not produce flowers till its eighth or ninth year, after which 
it bears fruit constantly for many years. The fruit is a globular, pendant 
drupe, about 5 cm. in diameter, of a yellowish-green color, the pericarp 
of which, when ripe, sphts in two, showing within it the kernel, completely 
surrounded by a fleshy, fibrous aril, or covering of a crimson color. This 
covering, when dried, furnishes the mace of commerce, while the inner 
kernel, which is a hard, brown seed, is the nutmeg. 

The jiutmeg seed or kernel, when gathered, is surrounded by a thick 
tegument, marked with depressions corresponding to the lobes of the 
aril or mace, and by a second thin, inner envelope, closely adhering to 
the seed. The whole seed is dried in the sun for about two months, or 
by the aid of heat, the tegument becoming separated from the kernel, 
and, by breaking with a hammer, is readily removed. The kernels 
are then commonly washed in milk of hme, and again dried, or they 
are sometimes treated with dry, powdered, air-slaked Hme. 

* Recently some very yellow samples of powdered mustard have appeared on the 
market that are apparently free from foreign color. Their method of manufacture is kepi 
secret. From the fact that they contain nearly, if not quite, the full content of fixed mus- 
tard oil that would be present if the oil had not been previously expressed, and for various 
other reasons, it is probable that the color is due largely to the presence of the fLxed oil, which 
has a deep-yellow color, and which has hitherto been generally removed for purposes of fine 
pounding and to avoid caking. 

In such samples, the oil, previously pressed out, is, after pounding, restored, and with 
it much of the color. Incidentally in such a process oil-soluble coal-tar dyes may conve- 
niently be dissolved in the mustard oil, in order to intensify the color, and the analyst should 
be on the outlook for such foreign colors. 



SPICES. 



361 



Liming is alleged to be practiced for the purpose of preventing sprout- 
ing of the seed. 

Nutmegs are spheroidal, sometimes nearly spherical, from 20 to 25 
mm. long and 15 to 18 mm. in diameter. The outer surface is some- 
what furrowed. The interior is composed of hard albumen, grayish 
brown in color, and oily. A cross-section of the kernel presents the 
appearance of numerous wavy, dark-brown Unes on the surface of the 
section. Near the end of the nutmeg, which is attached to the stem, 
is a small cavity, in which is the undeveloped embryo, with two cotyledons. 

Nutmeg contains a considerable amount of fi.xed oil, a volatile oil, 
starch, and albuminous matter. Its volatile oil is colorless, and is soluble 
in three parts of strong alcohol. The specific gravity of nutmeg oil 
varies between 0.865 '^'^d 0.920, and its specific rotary power (a)j,= i4 
to 28. 

Richardson's analyses of three samples of nutmeg are as follows: 





Water. 


A V, Volatile 
Ash. q;i_ 


Fixed 
Oil or 
Fat. 


Starch, 
etc. 


Crude 
Fiber. 


Albu- 
minoids. 


Nitro- 
gen. 


Whole limed. ..... 


6.08 
4.19 
6.40 


3-27 

2.22 

3-iS 


2.84 

3-97 
2.90 


34-37 
37-3° 
30.98 


36.98 
40.12 
41-77 


11.30 
6.78 
9-55 


5. 16 
5-42 
5-25 


-83 
-87 
.84 




Ground . 





Konig gives the following minimum and maximum composition of 
nutmeg : 



Water 

Albuminoids. . 

Volatile oil 

Fat 

Carbohydrates. 

Cellulose 

Ash 



Minimum. 


Maximum. 


4-2 


12.2 


S-2 


6.1 


2-5 


4.0 


31.0 


37-3 


29.9 


41.8 


6.8 


12.0 


2.2 


3-3 



Winton, Ogden, and Mitchell analyzed four samples of nutmeg of 
known purity, the following being maximum and minimum results: 



Moisture. 



Ash. 



Ether Extract. 



Total. 



Soluble in 
Water. 



Insoluble 
in HCl. 



Volatile. 



Nun-vola 
tile. 



Maximum. 
Minimum . 



10.83 
5-79 



3.26 
2-13 



1.46 
0.82 



o.oi 
0.00 



6-94 
2.56 



36-94 
28-73 



?62 



FOOD INSPECTION AND ANALYSIS. 





Alcohol 
Extract. 


Reducing 
Matters by 
Acid Con- 
version . as 
Starch. 


Starch by 
Diastase. 


Crude 
Fiber. 


Nitrogen 
X6.2S. 


Total 
Nitrogen. 




17-38 
10.42 


25.60 
17.19 


24.20 
14.62 


3-72 
2.38 


7.00 
6.56 


I 12 




1.05 






Microscopical Structure of Nutmeg. (Fig. 83.) — The thin-walled 
cells of the parenchyma of the endosperm or albumen are shown at 

(i), with starch grains. Simple and com- 
pound granules of the starch are shown at 
(2). Aleurone grains appear as shown at 
(3), and (4) represents in plan view the 
epidermis, or brown seed coat, with its 
numerous layers of flat cells. Powdered 
nutmeg under the microscope in water- 
mount shows most commonly a sponge- 
Hke, loose meshwork of bruised or broken 
Fig. 83.— Powtlered Nutmeg cellular tissue, with many starch granules, 
^'^.,"^^, iLroscope. 125. ^ occasional fragments of the epidermis. 

(After Moeller.) ° _ ^ 

Fig. 240, PI. XXX, is a photomicrograph 
of a water-mounted sample of pure nutmeg. The starch granules of 
nutmeg are different from other starches in appearance, being almost 
circular as a rule, quite uniform in size (averaging 0.006 mm. in 
diameter), and having very distinct central hyla. 

Adulteration of Nutmeg. — The U. S. standards for nutmegs 
are as follows: Non- volatile ether extract should be not less than 
25%; total ash should not exceed 5%; ash insoluble in hydro- 
chloric acid should not exceed 0.5%; crude fiber should not exceed 

10%. 

This spice is more often sold in the whole form, since the house- 
wife much prefers to grate the whole nutmeg, rather than to use 
the ground material. It is hence less liable to adulteration than 
the other spices, though of late more of the ground nutmeg is 
being sold in packages. Samples of ground nutmeg have been 
found in Massachusetts adulterated with wheat and nutshells. One 
sample was found to contain at least 25% of ground cocoanut 
shells. 



SPICES. 



363 



An inferior variety is known as the Macassar nutmeg. This lacks 
much of the agreeable pungency of the better grades. 

Mace. — The crimson-colored aril that surrounds the nutmeg kernel 
within the pericarp, as above described (p. 360), has many narrow, flattened 
lobes. In the process of drying to form the mace of commerce, it loses 
its brilliant red color, and turns a yellowish brown. When dried, it is 
brittle, somewhat translucent, and of a pungent odor. Whole mace 
appear on the market in the form of flat membranous masses, 3 to 4 cm. 
long. 

It contains no starch as such, but has a modified form of starch known 
as amylodextrin. This is a carbohydrate, CjaHejOji+HjO, which pro- 
duces with iodine a red coloration. Mace has a large amount of fixed 
oil, as well as considerable resinous and albuminous matter, and a vola- 
tile oil which much resembles that of nutmeg. 

The specific gravity of volatile oil of mace is rather higher than that 
of nutmeg oil. Its specific rotary power, (a)„=ioto2o. 

Konig's figures for the composition of mace are as follows: 





Minimum. 


Maximum. 


Water 


4-9 

4.6 

4.0 

18.6 

41.2 

4-5 
1.6 

45-1 


17.6 

6.1 

8.7 

29.1 

44.1 

8.9 

4.1 

55-7 


Albuminoids ... 


Volatile oil 


Fat 


Carbohydrates . . . 


Cellulose 


Ash 


Alcoholic extract 





Richardson gives the following as the results of analyses of three 
samples made by him: 





Water. 


Ash. 


Volatile 
Oil. 


Resin. 


Unde- 
ter- 
mined. 


Crude 
Fiber. 


Albu- 
minoids. 


Nitro- 
gen. 


Whole mace 

Ground mace 

Ground mace 


5-67 

4.86 

10.47 


4.10 
2.65 
2.20 


4.04 
8.66 
8.68 


27.50 
29.08 
23-33 


41.17 

35-50 
34.68 


8-93 
4.48 
6.88 


4-55 
6.13 

5 -08 


-73 
.98 
.81 





Winton, Ogden, and Mitchell's analyses of four samples of pure Banda 
or Penang mace, as well as of Bombay and Macassar mace, are sum- 
marized as follows: 



3^4 



FOOD INSPECTION AND ANALYSIS. 





Moisture. 


Ash. 


Ether Extract. 




Total. 


Soluble in 
Water. 


Insoluble 
in HCl 


Volatile. 


Non-vola- 
tile. 


True mace: Maximum 

Minimum 

Average 

Macassar 


12-04 
9-78 

11.05 
4-18 
0.32 


2-54 
I-81 
2.01 
2.01 
1.98 


1-33 
1 .06 

I-I3 
I. II 

1-37 


0.21 
0.00 
0.07 
O-03 
O-07 


8.61; 
6.27 
7-58 
5-89 
4-65 


23.72 
21.63 
22.48 
53-54 
S9-8I 


Bombay (adulterant) 




Alcohol 
Extract. 


Reducing 
Matters by 
Acid Con- 
version, as 
Starch. 


Starch by 
Diastase.* 


Crude 
Fiber 


Nitrogen 
X6.2S. 


Total 
Nitrogen. 


True mace: Maximum 

Minimum 

Average 

Macassar 


24-76 
22.07 
23.11 
32-89 
44-27 


34-42 
26.77 

31-73 
10.39 
16.20 


3° -43 
23-12 

27-87 
8.78 

14-51 


3-85 
2-94 
3-20 

4-57 
3.21 


7.00 
6.25 

6-47 
7.00 
5 -06 


1 .12 
1 .00 

1-03 
1 . 12 


Bombay (adulterant) 


0.81 



* The figures in this column do not express starch, but amylo-dextrin, which like starch may be 
determined by the diastase method. 



Microscopical Structure of Mace. — Fig. 84 shows characteristics of 
mace, (i) being a cross-section through it, (2) a plan view of the 

. epidermis, showing its elongated, often 
nearly rectangular cells, and (3) the large- 
celled parenchyma, in which are numerous 
oil globules. The contents of the paren- 
chyma cells are for the most part color- 
less, consisting of albumen, fat, and 
granules of amylodextrin, whicli are shown 
at (4). At (5) are shown fragments of 
vascular tissue. 

The water-mounted powder of pure 
mace shows no highly colored fragments, 
Fig. 84.— Powdered Mace under but as a mass, is white or grayish, and 
the Microscope. X125. (After ^^ j^^^^ texture. Occasional pale, yel- 

Moeller.) , • , , 11 

lowish, lumpy masses appear, and pale- 
brown fragments of the seed coating. The amylode.xtrin granules 
(wliich are colored red-brown by solution of iodine) are very 
small. 

Adulteration of Mace. — U. S. standard mace should contain not less 
than 20 nor more than 30% of non- volatile ether extract; nor more than 




SPICES. 365 

3% of total ash; nor more than 0.5% ash insoluble in hydrochloric acid; 
nor more than 10% of crude fiber. 

Turmeric and cereal starches are not uncommonly found in mace, 
but by far the most common adulterant is the so-called false, or wild 
mace, otherwise known as Bombay mace. 

Bombay Mace {Myristka jatua) is almost entirely devoid of odor 
or taste, being nearly as inert as so much starch. It is most properly 
regarded as an adulterant from its lack of pungency, even though in a 
sense it is a variety of mace. 

Its non-volatile ether extract is twice as high as that of Penang mace, 
and at room temperature the fixed oil of Bombay mace is a thick and 
viscous fat, while that of Penang and other maces is a thin oil. 

The refractive indices of the fixed oils of various species of pure, as 
well as of Bombay mace, as determined by Lythgoe in the writer's labora- 
tory, are as follows : 

«fl at 35° C. 
Banda Mace (i) 1.4848 

(2) 1.4747 

" _ " (3) 1-4829 

Batavia Mace (i) i .4893 

(2) 1.4975 

Papua Mace (i) i .4816 

(2) 1.4795 

West Indian Mace (i ) i .4766 

Bombay Mace (i) 1.4615 

(2) 1.4633 

The microscope indicates at once when Bombay mace is present 
in a sample. The oil glands situated in the outer layers of Bombay mace 
are very strongly colored, and contain a deep-red, resinous substance, 
very different from anything to be found in true mace. The glands of 
the more interior layers of wild mace have, moreover, a balsam-like 
substance of a bright-yellow color. In powdered Bombay mace, when 
mounted in water, nearly every field shows both the red and the yellow 
lumps in considerable number. 

Hejelmann's Test jor Bombay Mace * consists in saturating a strip 
of filter-paper with an alcoholic solution of the mace, and removing the 
excess of liquid by pressure between filter-paper. On treating with a 

* Pharra. Zeit., 1891. 



366 FOOD INSPECTION AND ANALYSIS. 

drop of dilute sodium or potassium hydroxide solution, a red color is 
produced in presence of the wild mace. 

Turmeric is tested for chemically as on p. 353. 

Macassar Mace is sometimes designated as wild mace, but it is by 
no means as inert as the Bombay variety, and possesses a slight mace- 
like odor. Its taste, while distinctive, is not that of true Penang mace. 
It is distinctly an inferior article, and its volatile oil content, as shown 
by the analyses on p. 364, is considerably below the minimum for true 
mace. 

REFERENCES ON SPICES. 
(See also References on the Microscope, p. 12.) 

Arnst, T., and Hart, F. Zusammensetzung einiger Gewurze. Zeits. fur Angew. 

Chem., 1893, 136. 
Beytkeen, a. Einige Paprika-Analysen. Zeits. fiir Unters. der Nahr. u. Genuss., 5, 

1902, 858. 
BussE, W. Ueber Gewurze. I. Pfeffer. II. Muskatniisse. III. Macis. Arbeit, a. d. 

Kais. Gesundheits., 1894, 9, 509; 1895, 11, 390; 1896, 12, 628. 
Delaite, J. Untersuchung von Senfmehl. Rev. Int. des Falsif., 1897, 10, 37. 
Dyer, u. Gh-bard. Unterscheidung zwischen unverfalschtem und extrahirtem Ingwer. 

Chem. Ztg., 1893, 17, 838. 
FoRSTER, A. Ueber Gewurze. Zeits. f. offentl. Chem., 1898, 4, 626. 
G^NiN, V. Epices et Aromates. Analyse des Matiferes Alimentaires. Girard et 

Dupr^, Paris, 1894. 
GiCHARD, B. Verfalschung von Zimmetrindenpulver. Zeits. f. Nahr. Hyg. Waarenk., 

1895, 9, 281. 
Hanausek, T. F. Zur Charakteristik des Cayenpfeffers. Zeits. fiir Nahr. Unters. Hyg., 

1893, 7, 297- 
Verfalshung von Gewurzen. Zeits. fiir Nahrungsm. Unters. u. Hyg., 1894, 8, 

95- 

Gewurzfalschungen. Apoth. Ztg., 1894, 582. 

Gefalschte und echte Macis. Rev. Inter. Fals., 1887, i, 23. 

Hefelmann, R. Zur Untersuchung von Macis. Pharm. Ztg., 1891, 36, 122. 
Held, F., u. Hilger, A. Zur chemischen Charakteristik der Bombay Macis. Forsch. 

uber Lebensm., 1894, i, 136. 
Jones, E. W. T. Analysis of Ginger. Analyst, 1886, 75. 
KRAiiER, H. Zur Priifung der Gewurznelken. Apoth. Ztg., 1894, 870. 
Leach, A. E. Microscopical E.xamination of Foods for Adulteration. Mass. State 

Board of Health An. Rep., 1900, pa>ge 679. 
Macfarlane, T. Mustard. Canada Inl. Rev. Dept. Bui. ig. 

Mustard. Canada Inl. Rev. Dept. Bui. 50. 

McGiLL, A. Cloves. Canada Inl. Rev. Dept. Bui. 73. 

Ground Ginger. Canada Inl. Rev. Dept. Bui. 48. 

Pepper. Canada Inl. Rev. Dept. Bui. 20. 



SPICES. 367 

Richardson, C. Spices and Condiments. U. S. Dept. of Agric, Div. of Chem., Bui. 

13, part 2, 1887. 
RoETTGER, H. Die Gewiirznelken, ihre Verfalschung und Beurtheilung. Ber. XI. 

Vers. d. treien Verein bayr. Vertreter d. angew. Chem. in Regensburg, 1892, 

S. 66. 
SoLSTEiN, P. Banda und Bombay Maces. Pharm. Ztg., 1893, 454, 467. 
Spath, E. Neue Verfalschungen von Gewiirzen. Forsch. iiber Lebensm., 1896, 3, 308 

Zur mikroskop. Priifung des Piments. Forsch. iiber Lebensm., 1895, 2, 419. 

VoGL, A., andHANAUSEK, T. F. Untersuchung der Gewurze. Sudd. Apoth. Ztg., 1896. 
Waage, T. Banda und Bombay Maces. Pharm. Centralbl., 1892, 23, 372. 
Warburg, O. Die Muskatnuss, ihre Geschichte, Botanik, Kultur, u. s. w. Leipzig, 

1897. 
Weigle, T. Untersuchungen iiber die Zusammensetzung des PfefFers. Ber. Pharm. 

Ges., 1893, 210. 
WiNTON, A. L. Spices. U. S. Dept. of Agric, Bur. of Chem., Bui. 65, 1902. 

Conn. Exp. Sta. An. Rep. 1898, 1899. 

Mass. State Board of Health An. Reports, 1883 et seq. 



CHAPTER XII. 



EDIBLE OILS AND FATS. 



Nature and Properties. — The oils and fats are the glycerin salts or 
glycerides of the fatty acids, the most important, on account of their 
occurrence in nearly all fats and oils, being the triglycerides of oleic, 
palmitic, and stearic acids, known as olein, palmitin, and stearin, 
respectively. 

Fats and oils are insoluble in water, and are almost insoluble in cold 
95% alcohol, though they are somewhat soluble in absolute alcohol. 
They are readily soluble in ether, petroleum ether, chloroform, amyl 
alcohol, oil of turpentine, and carbon bisulpliide. 

Following is a list of the fatty acids wliose glycerides are found in 
edible oils and fats, together with their melting- and boiling-points when 
these have been determined, and the oils and fats in which they occur. 



ACIDS OF THE ACETIC SERIES CnH„0,.* 



Name. 


Formula. 


Melting- 
point. 


Boiling- 
point. 


Occurrence in Oils and Fats. 


Butyrict 


C,H,0, 


-2°tO-f2° 


162.3 


Butter, cocoa butter. 


Caproicf 


CeH^O, 


.... 


200 


Butter, cocoanut oil. 


CaprvUcf 


CsH.eO, 


16.5 


236 


l( u 


Capricf 


C,„H,,0, 


31-3 


268-270 


tt tt 


Laurie 


C,„H„,0, 


43-6 


176 


Cocoanut oil, cocoa butter. 


Mvristic 


CuH^Oj 


53-8 


196.5 


' ' sesame oil. 


Palmitic 


C„H3,0, 


62 


215 


Nearly all oils and fats. 


Stearic 


C,sH3,0, 


71-71-5 


232-S 


Fats and nearly all oils, except 
olive and com. 


Arachidic 


C20H10O2 


77 


. - . - 


Peanut, olive (trace), rape (trace). 


Behenic 


C^^H^Gj 


83-84 


.... 


Rape, mustard. 


Lignoceric. . . . 


C,,H,,0, 


81 





Peanut. 



* L,ewkowitsch. Oils, Fats, and Waxes, p. 24. ' 

t These four acids are the only ones that can be distilled under ordinary pressure without becom- 
ing decomposed. 

368 



EDIBLE OILS AND FATS. 
ACIDS OF THE OLEIC SERIES C„Hj„_,0,. 



369 



Name. 


Formula. 


Melting- 
point. 


Boiling- 
point. 


Occurrence in Oils and Fata. 


HypogaDic 

Oleic 

Iso -oleic * 

Rapic 

Erucic 


CieHjgOj 
C1SH34O2 
C„H3,0, 
C,aH3,0, 
C„,H,,Oj 


33° 

14° 

44-45° 

33-34° 


236° 
232.5° 

264° 


Peanut. 

Nearly all fats and oils. 

Rape and mustard. 



ACIDS OF THE LINOLEIC SERIES C„H,„_,0,. 



Name. 


Formula. 


Melting- 
point. 


Boiling- 
point. 


Occurrence in Oils and Fats. 


Linoleic 


C18H32O2 


Under-i8°C. 




Olive, cottonseed, peanut, sesame, 
cocoa butter, poppy seed, sun- 
flower. 



* Solid oleic acid. 

Saponification of Fats and Oils. — By this term is meant the decom- 
position of the glycerides composing the fats or oils, whereby the tri- 
atomic alcohol glycerin and the fatty acids are separated. The sapon- 
ification process is commonly applied in carrj'ing out many determina- 
tions of value on fats and oils, such as those of the soluble and insoluble 
fatty acids, the Reichert value, etc. As commonly carried out, the tri- 
glycerides are first split up into glycerin and the soluble soaps of the fatty 
acids by the action of caustic alkali, usually in solution in alcohol. This 
part of the process in the case of a given oil, composed, for example, of 
stearin, olein, and palmitin, is illustrated as follows: 

(i) C3H,(C,,H350,)3+ 3KOH = C3H,(OH)3+ 3K(C„H3,0,) 

Stearin or Glycerin Potassium 

trig] yceryl stearate 

stearate 

(2) C3H,(C,„H3.03)3+ 3KOH = C3H,(OH)3+ 3K(C,„H3,0,) 

Palmitin or Potassium 

trig] yceryl palmitate 

palmitate 

(3) C3H,(Q,H3302) + 3KOH = C3H5(OH)3+ 3K(C,,H330,) 

Olein or tri- Potassium 

glyceryl oleate oleate 

These "soaps, " or potassium salts of the fatty acids, are further decom- 
posed by the action of sulphuric acid into the free fatty acids and potas- 
sium sulphate, in the case of potassium stearate, as follows: 

2K(C,,H330,) + H3SO, = K,SO,-^2H(C„H3502) 

Potassium stearate Stearic acid 



370 FOOD INSPECTION AND ANALYSIS. 

Analysis of Edible Oils and Fats. — No class of food products presents 
more difficulties in the analyst than the fats and oils, in that the various 
physical and chemical constants by which one derives information as 
to their nature or purity diflfer within such wide limits that it is not easy 
to prescribe absolute standards. Many elements enter in to cause this 
variation, chief among which are, in vegetable oils, the large number 
of varieties of fruits or seeds from which each oil is in different localities 
obtained, as well as the various grades of each oil with respect to refining. 
In the animal fats, butter and lard, the quality of the food on which the 
animal is reared undoubtedly influences the chemical constants of the 
fat, and in all fats and oils much depends upon their age, and the con- 
ditions under which they are kept as to temperature, exposure to light and 
air, etc. 

Rancidity is undoubtedly an oxidation process, due to the action of 
air and light rather than to that of ferments or micro-organisms, as was 
formerly supposed. It seriously affects various constants, and care 
should be taken by the analyst to keep all samples in a dark, cool place 
and as far as possible in tight containers. 

As a rule rancidity develops more readily in the liquid oils in which 
the olein predominates than in the sohd fats, which are composed more 
largely of palmitin and stearin. 

Judgment as to Purity of a given oil or fat should not be hastily given. 
It is sometimes comparatively ea«y to prove the presence and approx- 
imate amount of an adulterant, the various constants all serving to identify 
it without fail. Again, in some cases it is easy to pronounce the sample 
adulterated, without being able to definitely state the exact nature of 
the adulterant. The tests to be employed depend on the particular 
case in hand. Sometimes the determination of two or three constants 
will be sufficiently definite. 

Again, a large number of tests must be made before one can intel- 
ligently form an opinion. It should be borne in mind that skillful manu- 
facturers may adulterate the 'edible oils and fats with mixtures intended 
to confuse the chemist, and yield on analysis constants that are entirely 
misleading. 

Much information may usually be gained by carefully noting the color, 
taste, odor, and viscosity of the sample. 

Filtering, Measuring, and Weighing of Fats. — These manipulations 
naturally present some difficulties in the case of solid fats not encountered 
with liquid oils. 



EDIBLE OILS AND FATS. 



371 



A steam- or hot-water-jacketed funnel as represented in Fig. 85 is con- 
venient for filtering fats, or, in the absence of this contrivance for keeping 
the fat in a molten condition, a hot funnel may be employed, the filtering 
being best conducted in a warm closet or oven. 

Portions of the fat for the various determinations may be measured 
off with a pipette while the fat is still hot, but a much better way is to 




Fig. 85. — ^Jacketed Funnel for Hot Filtration. 

cool the fat (over ice if necessary), and to weigh the desired amounts in 
the solid state. This can very readily be done by placing a flat platinum 
or other dish on the scale-pan, covering it with a moderately thick, cut 
filter-paper somewhat larger in diameter than the dish and designed to 
lie flat upon it, and taking the tare of both dish and filter. The solidified 
fat, after mixing with a stirring-rod, is transferred in one or more por- 
tions to the middle of the filter, and the exact weighed amount is obtained, 
after which, by carefully handling the edges of the filter and folding in 
the latter, the fat with the filter may be transferred to a flask or other 
receptacle. 

Specific Gravity. — The specific gravity of liquid oils is most con- 
veniently taken either at room temperature or at 15.5°, being always 



372 



FOOD INSPECTION AND ANALYSIS. 



best referred to the latter. Either the hydrometer, Westphal balance, 
Sprengel tube, or pycnometer are employed, according to the degree of 
accuracy required. If taken at any other temperature than 15.5°, say 
at room temperature, T, the specific gravity may be computed at 15.5° 
by the formula 

G = G'+A'(r- 15.5).* 

in which G is the specific gravhy at 15.5°, G' the specific gravity at 7^, 
and K a factor varying with the different oils as follows: 

FACTORS FOR CALCULATING SPECIFIC GRAVITY. 



Oil. 


Correction 
for 1° C. 


Observer. 


Cod-liver oil. 


0.000646 
.000658 
.000629 
.000655 
.000620 
.000624 
.000629 


A. H. Allen 
C. M. WetheriU 
C. M. Stillwell 
A. H. AUen 

H 


Lard oil 






Rape oil 


Sesame oil 







Unless the most accurate work is necessary, it is sufficient to assume 
in all cases if = 0.00064, in which case the formula becomes G=G' + 
o.ooo64(r-is.5). 

In the case of solid fats, it is most convenient to take the specific 
gravity of the melted fat. This may be done at any temperature above 
the melting-point by either of the instruments above described, or at the 
temperature of boiling water by the Westphal balance or pycnometer. 

When the pycnometer is used, it is immersed in a water-bath, the 
temperature of which is well above the melting-point of the fat, say 35° 
or 40°. While still immersed nearly to the neck, it is carefully filled 
with the melted fat and kept in the bath till the fat has acquired the same 
temperature, usually about fifteen minutes. If the pycnometer is pro- 
vided vnth a thermometer stopper, this will serve to indicate the tem- 
perature; otherwise a separate thermometer is inserted in the bath. 
The pycnometer is then removed, cleaned, dried, and cooled to the room 
temperature, at which it is weighed. The factors employed in the above 
formula for calculation of specific gravity of sohd fats at 15.5° are as 
follows : 

* Winton, Conn. Exp. Sta. Rep., 1900, p. 149; Allen, Com. Org. Anal., 3d ed., vol. 2, 
Pt- I. P- 33- 



EDIBLE OILS AND F/ITS. 



373 



FACTORS FOR CALCULATING SPECIFIC GRAVITY. 



Fats. 


Correction 
for 1° C. 




0.000717 
.000675 
.000650 
.000617 
.000674 
. 00064 2 
.000657 




Lard 


Butter fat 






Palm nut oil 





Either the Westphal balance or the hydrometer may be used directly on 
the melted fat, carefully recording the temperature and calculating as above. 

For making the determination with the Westphal balance at the tem- 
perature of boiling water, the melted fat is contained in a vessel immersed 
in a boiling water-bath, and kept sufficiently long to acquire that tem- 
perature, which is carefully noted. 

A. O. A. C. Method* — The pycnometer, being perfectly clean, is 
first weighed with the stopper, after which it is filled with freshly boiled, 
hot, distilled water and placed in a bath of boiling water, where it 
is kept for half an hour, replacing any loss by evaporation in the flask 
with boihng distilled water. The stopper of the pycnometer, previously 
heated at 100°, is then inserted, and the flask removed and wiped perfectly 
dry. It is then allowed to cool nearly to room temperature, and weighed 
on the balance when the temperature is the same as that of the room. 

The flask, being again perfectly clean and dry, is filled while hot with 
freshly melted and filtered hot fat, free from air-bubbles, and kept for 
half an hour in a boiling water-bath, after which the stopper, previously 
heated as before to 100°, is inserted, and the flask taken from the bath 
and wiped dry. It is then allowed to cool and weighed when the tem- 
perature of the room has been reached. 

The specific gravity is calculated by dividing the weight of the fat 
by the weight of the water previously found. 

Having once obtained the weight of the flask and the weight of a 
volume of water contained therein when at boiling temperature, these 
figures can be constantly used without redetermination, if the flask is 
cleaned thoroughly each time. 

Calculation of Proportions of Two Known Oils in Mixture.f — This 
may be roughly accomplished from the specific gravity of the mixture 
and of the oils known to compose it. 

* U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 21. 
t Villiers et Collin, Les Substances Alimentaires, p. 646. 



374 



FOOD INSPECTION /IND /tNALYSIS. 



Let G = specific gravity of mixture, 
D and Z)' = specific gravity of the two oils, 
and X = % oil of specific gravity D. 
loo(G-D') 



Then A' 



D-D' 



EDIBLE OILS AND FATS ARRANGED IN ORDER OF SPECIFIC GRAVITY. 



Cocoa butter . 
Mutton tallow, 
Beef " , 

Butter 

Lard 

Poppy seed oil. 
Sunflower oil . 

Com oil 

Cottonseed oil 
Sesame oil. . . . 

Peanut oil. 

Mustard oil. . . 

Olive oil 

Rape oil 



Specific Gravity. 


.976 to .950 


•953 " 


937 


-952 " 


943 


.940 " 


926 


-938" 


934 


.927 " 


924 


.926 " 


924 


.926 " 


921 


■925 " 


922 


.924 " 


923 


.921 " 


917 


.920 ** 


916 


.918 " 


916 


.917 " 


913 



The Viscosity, or degree of fluidity in the case of edible oils, is of less 
importance than in the case of lubricating oils, and gives little insight 
into the nature or purity of the sample. 

Hence a discussion of various viscosimeters and their use will not 
be included here, but reference is made to Lewkowitsch * for information 
regarding them. 

Melting-point. — A piece of small glass tubing is drawn out to a cap- 
illary open at both ends, and this is inserted into a bealier of the fat, melted 
at a temperature slightly above its fusing-point. A portion of the melted 
fat being drawn up into the capillary, the latter is removed and the fat 
allowed to solidify spontaneously. After an interval of not less than 
twelve hours, the capillary is attached by a rubber band to the stem of 
a delicate thermometer (preferably capable of being read to tenths of a 
degree), the portion of solidified fat being opposite the thermometer bulb. 
A test-tube containing water is held in the neck of a flask in such a man- 
ner as to be immersed in water contained in the flask, as shown in Fig. 
86, the flask being held on the ring of a stand, with wire gauge inter- 
posed between flask and flame. The thermometer with attached capil- 
lary are then held immersed in the water of the test-tube and below the 



* Chemical Analysis of Oils and Fats, pp. 102-112. 



EDIBLE OILS ^ND FATS. 



375 



level of the water in the flask, as shown. The water in the flask is then 
heated very gradually, so that the rise of temperature as shown by the 
thermometer docs not exceed 0.5° C. per minute, the exact temperature 
at which fusion of the fat occurs being recorded as the meking-point. 

The flame is then removed, and the temperature at which the fat 
solidifies is noted as the solidifying-point. 

The mean of two or three determinations is usually taken as the true 
melting and solidifying-points. 





Fig. 86. 
Fig. 86. — Apparatus for Determining Melting-point 
fat shown on the right, enlarged. 

Fig. 87. — Reichert Flask with Card Inserted for Quick Evaporation. 



Fig. 87. 
Capillary tube with enclosed 



Reichert-Meissl Process for Volatile Fatty Acids. — This 
process has undergone various modifications from time to time. Reichert 
originally used 2.5 grams of fat, but Meissl, who improved the process, 
used 5 grams, so that the Reichert-Meissl number is now expressed on 
the basis of 5 grams of fat. The method is conveniently carried out as 
follows : 

Five grams of the fat are transferred to a dry, clean Erlenmeyer flask 
of about 300 cc. capacity, 10 cc. of 95% alcohol are added, and 2 cc. of 
sodium hydroxide solution (prepared by dissolving 100 grams of sodium 
hydroxide in 100 cc. of water). The flask vnth its contents is then heated 



376 



FOOD INSPECTION /iND ANALYSIS. 



on a water-bath with a funnel in the neck, which satisfactorily replaces 
the return-flow condenser originally prescribed. The heating is con- 
tinued with occasional shaking till saponification is complete. This 
stage of the process is indicated by the appearance of the solution, which 
is then perfectly clear and free from fat globules. 

The condenser-funnel being removed, the contents of the flask are 
next evaporated by continued heating over the bath to dryness. This 
may be hastened by inserting a card in the neck of the flask, as shown 
in Fig. 87, thus starting a circulatory movement to the air through the 
flask. 

The dry soap thus formed is then dissolved by warming on the water- 
bath with 135 CO. of added water, shaking the flask occasionally. After 




Fig. 88. — Apparatus for Reichcrt-Meissl Distillation. 

cooling, 5 cc. of dilute sulphuric acid (200 parts sulphuric acid in i liter 
of water) are added, and the fatty acid emulsion formed is melted by 
heating the flask on the water-bath, the flask being corked during the 
heating. The fatty acids are completely melted when they form an oily 
layer on the surface of the solution. 

Scraps of pumice stone joined by platinum vnres are next placed in 
the flask to prevent bumping, and the flask is properly connected with 
the condenser for distilling, as shown in Fig. 88. A flask graduated at 
no cc. is used as a receiver, the funnel placed therein being provided 
■with a loose tuft of absorbent cotton to serve as a filter. The distilla- 



EDIBLE OILS AND FATS. 



377 



tion is conducted by so grading the heat that the receiving flask is 
filled with the distillate in about thirty minutes. 

Finally the entire distillate is titrated with dccinormal sodium hydrox- 
ide, using 0.5 cc. of a solution of phenolphthalein as an indicator. The 
number of cubic centimeters of decinormal alkali required to neutralize 
the acidity of the distillate from 5 grams of the fat in the manner described 
expresses what is known as the Reichert-Meissl number. 

Lefjmann and Beam's Modification.* — Five grams of the fat placed in 
the flask arc treated with 20 cc. of a solution of soda in glycerin (20 cc. 
of a 50% solution of sodium hydroxide in 180 cc. of glycerin), heating the 
flask till the contents are completely saponified. The solution becomes 
perfectly clear, showing complete saponification in about five minutes, 
after which 135 cc. of water are added to the clear soap solution, at first 
drop by drop to prevent foaming; 5 cc. of the dilute sulphuric acid are 
then added, and the distillation conducted at once without first melting 
the fatty acids. 

EDIBLE OILS AND FATS IN THE ORDER OF THEIR REICHERT-MEISSL. 

NUMBER. 





Lowest. 


Highest. 


Average. 


Butter . .... 


24-5 
6.65 

1.32 

0.70 
0.58 


32 
7.8 

5.0 

1.20 
0.90 


28.25 
7-2 
3-2 
3.16 


Cocoanut oil 




Corn oil. . 




Cottonseed oil . . 


°-9S 
0-95 

0.74 






Olive oil 




°-S 





Determination of Soluble and Insoluble Fatty Acids. — A. O. A. C. 

Method.^ — Soluble Acids. — Five grams of the fat are weighed out and trans- 
ferred to an Erlenmeyer flask of the same size and in the same manner 
as that used for the Reichert-Meissl process. 50 cc. of alcoholic potash 
solution are added (40 grams of potassium hydroxide in i liter of 95% 
redistilled alcohol) and the flask, provided with a return-flow condenser, 
is heated on the water-bath till saponification is complete, as evidenced 
by the clear solution free from fat globules. The alcoholic solution of 
potash is preferably measured from a pipette, from which it is allowed 
to drain for a noted interval of time, say thirty seconds. 

* Leffmann and Beam, Select Methods of Food Analysis, p. 146. 
t U. S. Dept. of Agric, Div. of Chem., Bui. 46, p. 47. 



378 FOOD INSPECTION AND AN /I LYSIS. 

After complete saponification, the condenser is removed and the 
alcohol is evaporated by further heating. One or more blanks are pre- 
pared at the same time, using the same 50-cc. pipette for measuring, and 
applying the same time limit for draining the pipette. The blaniis are 
first titrated, after evaporation, vi'iih. half-normal hydrochloric acid, 
using phenolphthalein as an indicator. Then add to the flask contain- 
ing the fatty acids i cc. more of the half-normal acid than is found neces- 
sary to neutralize the alkali in the blanks, after which the flask is again 
heated with a funnel in the neck till the fatty acids have completely sepa- 
rated in a layer on top of the solution. Then cool the flask in ice water 
till the fatty acids are solidified, after which decant the hquid portion 
through a filter, previously dried in the oven and weighed, into a liter 
flask, keeping the solid mass of fatty acids intact. Next add 200 or 300 
cc. of hot water to the flask containing the fatty acids, and again melt 
over the water-bath till they collect as before on top, having again inserted 
the funnel to act as a condenser, and occasionally shaking the contents 
of the flask during heating. Cool as before in ice water, after which 
again decant the hquid from the sohd mass through the same filter into 
the liter flask. Repeat this process of washing, melting, coohng, and 
decanting three times, receiving all the wash water through the same 
filter in the same flask. Make up the washings with water to the liter 
mark, and, after mixing, two portions of 100 cc. each are titrated with 
tenth-normal sodium hydroxide, using phenolphthalein for an indicator. 
Each reading is muhiplied by ten to represent the total volume, and the 
figure thus obtained represents the number of cubic centimeters of tenth- 
normal alkali necessary to neutralize the acidity of the soluble fatty acids, 
together with the excess of half-normal acid used, amounting to i cc. 
This I cc. of half-normal acid corresponds to 5 cc. of tenth-normal alkali, 
hence 5 cc. are to be deducted from the total number of cubic centimeters 
required for the titration, the corrected figure thus obtained being multi- 
plied by the factor 0.0088, which gives the weight of soluble fat acids in 
the 5 grams of the sample, calculated as butyric acid. 

Insoluble Acids. — Transfer the fatty acids left in a cake in the flask 
from the separation of the soluble acids, to a weighed glass evaporating 
dish, using strong alcohol to wash them out thoroughly. Dry the fiker used 
in the separation, transfer it to an Erlenmeyer flask, and thoroughly 
wash it with strong alcohol, transferring all the washings to the dish. The 
alcohol is then evaporated by placing the dish on the water-bath, after 
which it is dried for two hours in the air-oven at 100°, cooled in the desic- 



EDIBLE OILS ^ND F/1TS. 379 

cator, and weighed. After once heating for two hours, cooHng, and weigh- 
ing, heat again for half an hour, cool, and weigh. If a considerable loss 
in weight is found, heat for an additional half-hour. It is best, however, 
to avoid too prolonged heating, lest oxidation of the fatty acids should 
produce an increase in weight. 

Hehner's Method. — Transfer the fatty acids left in the original Erlen- 
meyer flask to the thoroughly wet, tared filter, washing out the flask 
with hot water, thus bringing all the fatty acids upon the filter, which, 
if of good quahty and thoroughly wet beforehand, will retain them. If, 
however, oily particles are noticed in the filtrate, they may be solidified 
by coohng in ice water, and afterwards removed by a glass rod and trans- 
ferred to the filter. After draining dry, the funnel is immersed in cold 
water to solidify the fatty acids, and the filter containing them is trans- 
ferred to a weighed dish, which is dried for two hours in the oven at ioo°, 
cooled in the desiccator, and weighed, subtracting the weight of the 
dish and filter. 

EDIBLE OILS AND FATS ARRANGED IN ORDER OF INSOLUBLE FATTY 

ACIDS. 

Mustard oil 96.2 to 95.1 

Cottonseed oil 96 "95 

Com oil 96 "93 

Lard 96 "93 

Peanut oil 95-8 

Sesame oil 95-7 

Beef tallow 95-6 

Mutton tallow 95-5 

Poppyseed oil 95-2 " 94.9 

Rape oil 95-1 

Sunflower oil 95 

Olive oil 95 

Cocoa butter 94-6 

Cocoanut oil 90 " 88.6 

Butter 89.8 " 86.5 

Saponification Number. — Koettstorfe/s Method. — By the saponifi- 
cation number is meant the number of milhgrams of potassium hydroxide 
necessary to completely saponify i gram of the fat. Between i and 2 
grams of the fat are transferred in the usual manner (see p. 371) to an 
Erlenmeyer flask, and 25 cc. of the alcoholic potash solution (40 grams of 
potassium hydroxide in i liter of 95% alcohol) are added with a graduated 
pipette, which is allowed to drain for a noted period of time, say thirty 
seconds. The determination should preferably be made in duplicate. 



38o 



FOOD INSPECTION AND ANALYSIS. 



Conduct the saponification as in the case of the soluble fatty acids by 
heating on the water-bath. After saponification, remove from the bath, 
cool, and titrate with half-normal hydrochloric acid, using phenolphthal- 
ein as an indicator. Titrate also several blanks in which 25 cc. of the 
alcohoHc potash solution are measured out with the same pipette as before, 
and allow to drain for the same amount of time. Subtract the number 
of cubic centimeters of half-normal acid necessary to neutralize the alkali 
in the case of the saponified fat from that necessary to neutralize the 
blank, multiply the result by 28.06, and divide the product by the number 
of grams of fat taken. 

EDIBLE OILS AND FATS ARRANGED IN ORDER OF THEIR SAPONIFICA- 
TION NUMBER. 



Cocoanut oil 

Butter 

Cocoa liutter 

Beef tallow 

Lard 

Lard oil 

Cottonseed stearin 
Poppyseed oil ... . 
Cottonseed oil ... 

Peanut oil 

Sunflower oil .... 

Sesame oil 

Olive oil 

Corn oil 

Rape oil 

Black mustard oil 
White mustard oil. 



Maximum. 


Minimurn 


246.2 


268.4 


225 


230 


192 


202 


193-2 
195-3 
195 


200 

196.6 

196 


194.6 

190 

191 


195. 1 

198 

196.6 


190 


197 


193 
187.6 

185 
188 


194 
192.4 
196 
193-4 


170.2 


179.2 


174 


174.6 


170.3 


171-4 



Mean. 



257-3 
227.5 

197 

196.6 

196 

195-5 

194.8 

194 

193.8 

193-5 

193-5 

192.6 

191-5 
190.7 
174.6 

174-3 
170.8 



The Iodine Absorption Number.— This determination is based ort 
the well-known property of the unsaturated fatty acids to absorb a fixed 
amount of iodine under given conditions of time, strength of reagent, etc. 

Hiibl's Method.* — The following reagents are necessary: 

(i) Iodine Solution, made by dissolving 26 grams of pure iodine in 
500 cc. of 95% alcohol, and, separately, 30 grams of mercuric chloride 
in 500 cc. of the same strength of alcohol. Filter the latter solution, 
if necessary, and mix the two together, allowing the mixture to stand 
at least twelve hours before using. 

(2) Decinormal Thiosulphate Solution, made by dissolving 24.6 grams 
of the freshly powdered, chemically pure salt in water, and making up 
to I liter. 



* As adopted by the A. O. A. C, U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 24. 



EDIBLE OILS AND F/ITS. 38'! 

(3) Starch paste, prepared by boiling i gram of starch in 200 cc. of 
water for ten minutes, then cooling. 

(4) Potassium Iodide Solution, made by dissolving 150 grams of the 
salt in water, and making up the volume to i liter. 

(5) Potassium Bichromate Solution for standardizing the thiosulphate, 
made by dissolving 3. ^74 grams of chemically pure potassium bichromate 
in distilled water, and making up the volume to i liter. 

The sodium thiosulphate solution is standardized as follows: 20 cc. 
of the potassium bichromate solution are introduced into a glass-stoppered 
flask together with 10 cc. of potassium iodide and 5 cc. of strong hydro- 
chloric acid. Then slowly add from a burette the sodium thiosulphate 
solution, till the yellow color of the solution has nearly disappeared, after 
which a little of the starch paste is added, and the titration carefully con- 
tinued to just the point of disappearance of the blue color. The reaction 
which takes place is as follows: 

K2CrjO,4-i4HCl+6KI = 2CrCl3-f 8KCI-I-6I+7H2O. 

The equivalent of i gram of iodine in terms of the thiosulphate solu- 
tion is found by muUiplying the number of cubic centimeters of the latter 
solution required for the above titration by 5. 

If, for example, 16.4 cc. of the thiosulphate solution are required 
for 20 cc. of the bichromate solution, then i gram of iodine is equivalent 
to 16.4X5 = 82.0 cc. of sodium thiosulphate solution, or i cc. of the thio- 
sulphate solution =^5 = 0.0122 gram of iodine, i cc. of exactly deci- 
normal thiosulphate is theoretically equivalent to 0.0127 gram of iodine. 

Method oj Procedure. — Place i gram of the solid fat, or from 0.2 to 
0.4 gram of oil, in a glass-stoppered flask or bottle of 300 cc. capacity. 
In the case of oils, this may conveniently be done by difference, weigh- 
ing first a small quantity of the oil in a beaker with a short piece of glass 
tubing to serve as a pipette, transferring a number of drops of the oil 
from the beaker to the bottle, and again weighing the beaker and con- 
tents. The number of drops of oil required for the desired weight is 
first ascertained experimentally. Dissolve the oil in 10 cc. of chloro- 
form, and after solution has taken place, add 30 cc. of the iodine solution, 
shake, and set the flask in a dark place for three hours, shaking occasion- 
ally. When ready for the titration, add 20 cc. of the potassium iodide 
solution (the purpose of which is to keep in solution the mercuric iodide 
formed, which would otherwise precipitate on dilution) and 100 cc. of 



382 



FOOD INSPECTION AND AN/I LYSIS. 



distilled water. Titrate the excess of iodine by the thiosulphate solution, 
which is slowly added from a burette till the yellow color has nearly dis- 
appeared, after which, by the addition of a little starch paste, the final 
few drops of thiosulphate are added to dispel the blue color. Near the 
end of the reaction the flask should be stoppered and vigorously shaken, 
in order that all the iodine may be taken up, and sufficient thiosulphate 
should be added to prevent a reappearance of any blue color in five 
minutes. 

Two blanks are conducted at the same time and in similar flasks or 
bottles, in exactly the same manner as in the case of the above titration, 
except that the fat is omitted. This is to get the true value of the iodine 
solution in terms of the thiosulphate solution. 

Suppose, for example, in the case of the blanks, 30 cc. of the iodine 
solution required in one instance 46.1 cc. of sodium thiosulphate solution, 
and in the other 46.5 cc. The mean is 46.3. Suppose 15.1 cc. of thio- 
sulphate solution were required for the excess of iodine remaining over 
and above that absorbed by i gram of the fat in the above process. Then 
the thiosulphate equivalent to the iodine absorbed by the fat would be 
46.3 — 15.1 = 31.2 cc, and the per cent of iodine absorbed would be 31. 2X 
o.oi 22 X 100 = 38.06. 



EDIBLE OILS AND FATS ARRANGED IN ORDER OF THEIR HUBL NUMBER. 



Lowest. 



Highest. 



Average. 



Poppyseed oil 

Sunflower oil 

Com oil 

Cottonseed oil 

Sesame oil 

Rape oil 

Black mustard oil 
White mustard oil. 

Peanut oil 

Cottonseed stearin 

Olive oil 

Lard oil 

Lard 

Beef tallow 

Mutton tallow 

Cocoa butter 

Butter 



132.6 


143-3 


138 


118 


133-3 


125-7 


III. 2 


123 


117. 1 


108 


no 


109-S 


103 


no 


107-5 


99 


106 


102.5 


96 


106 


lOI 


92.1 


97-7 


94-9 


85.6 


103 


94-3 


88.7 


93-6 


91.2 


79 


88 


83-S 


.=;6 


85 


70.5 


46 


64 


55 


35-4 


44 


39-7 


32-7 


46.2 


39-5 


32 


37-7 


34-9 


25-7 


37-9 


33-3 



The Hiibl method has long been almost universally used for esti- 
mating the per cent of iodine absorbed, but is open to serious objections, 
chief of which are the tendency of the iodine solution to lose strength, 



EDIBLE OILS AND FATS. 



383 



and the length of time required to insure saturation of the oil with the 
iodine. 

Of late two other methods have come into prominence, viz., the 
Wijs and the Hanus. The reagents in both these methods hold their 
strength for months without change, and the time required for carrying 
out the reaction in the case of most of the edible oils and fats is very short. 

Of the three methods, that of Hanus has the advantage of greatest 
simplicity in the composition and preparation of the chief reagent. 

Tolman and Munson* have shown that with oils and fats having 
iodine numbers below 100, the three methods give practically identical 
figures, while with oils having high iodine numbers, the Wijs and Hanus 
methods give higher results than the Hiibl, but are doubtless more nearly 
correct. 

The following are comparative results of the three methods:* 



^ >. 






ioi-i 



•.■z3 



C 3 o 



C a^ b 



u C ™ 

C ^ (A 



36 

3 

5 

2 

I 

3 

I 
3 



Cocoanut oil. 
Butter— 



Oleo oil 

Oleomargarine 



minimum . 
maximum. 



Lard oil — • 
Olive oil — 

Peanut oil — 

Mustard oil — 

Rape oil — 

Sunflower oil . 
Cottonseed oil- 



-mmimum . 
maximum, 
minimum . 
maximum, 
minimum . 
maximum, 
average . . . 
minimum . 
maximum, 
minimum . 
maximum, 
minimum . 
maximum. 



Sesame oil. 
Com oil — 



Poppyseed oil — 



■ minimum , 
maximum. 



minimum . 
maximum, 
minimum . 
maximum. 



34 
35 
42 
52 
66 
69 
73 
79 
89 
84 
94 
107 
98 
"3 
100 

lOI 

106 

103 
106 
106 
119 
123 
133 
134 



9 

35 

36 

43 

52 

66 

70 

74 

79 

91 

85 

95 

109 

104 

iiS 

104 

105 
109 

i°5 
107 
107 

122 
129 
135 
139 



°5 



35 
35 
43 
52 
64 
69 

73 
80 
90 
84 
94 
107 

103 
116 
102 

i°5 
107 

i°5 
107 
106 
119 
126 
132 
138 



+ 0.12 
+ 1.1 
+ 0.9 
+ 0.9 
+ 0.4 

-0-3 
+ 1.2 
4-0.7 
+ 0.7 
+ 1.6 

+ "■3 
+ 0.7 
+ 1.8 
+ 5-9 
+ 5-2 
+ 3-9 
+ 4-4 
+ 2.8 

+ 1-5 
+ 1.1 
+ 0.6 

+ i-o 
+ 5-8 
+ 1.8 

+ 4-2 



-0-33 
+ 0.6 

4-0.0 
+ 0.7 
-o-S 
-1-5 

+ 0-S 

4-C.2 

+ 1-4 
+ 0.2 
+ 0.6 
— 0.1 
+ 0.0 
+ 5-4 
+ 3-8 

-f2.6 

+ 3-8 
+ 0.8 
+ 1-4 
-f 1.6 

+ 0.1 
+ 0.4 
+ 2.7 
-0-5 
+ 3-5 



Hanus' Method.f — Reagents. — Iodine Solution. — Dissolve 13.2 grams 
of pure iodine in i liter of pure glacial acetic acid (99%), and to the cold 

* Jour. Am. Chem. Soc, 25 (1903), p. 244. 

t Zeits. f. Unters. Nahr. u. Genus., 4 (1901), p. 913. Also Hunt, Jour. Soc. Chem. Ind, 
21 (1902), p. 454. 



3*4 FOOD INSPECTION AND ANALYSIS. 

solution add 3 cc. of bromine, or sufficient to practically double the halo- 
gen content when titrated against the thiosulphate solution, but with 
the iodine slightly in excess. 

Decinormal Thiosulphate Solution, Starch Paste, and Potassium Iodide 
Solution, as in Hiibl's method. 

Method oj Procedure. — Proceed as in Hiibl's method, substituting 
30 cc. of the Hanus iodine reagent for that of Hiibl, stirring the solu- 
tion before adding the water, and, instead of adding 20 cc. of the 
potassium iodide solution, use only 10 cc. 

Only half an hour is required for full saturation of the oil by the 
iodine in the Hanus method, as against three hours in the Hiibl. In 
case of the non-dr)'ing oils and fats, the reaction takes place in from 
eight to fifteen minutes, though it is best to let the flask set for half an 
hour at least, in all cases. With oils having an iodine number in excess 
of 100, Tolman and Munson recommend one hour's standing. 

On account of the high coefficient of expansion of acetic acid, care 
should be taken that the temperature is the same when the iodine solu- 
tion is measured for the blank and for the determination, as otherwise 
a serious error may be introduced. 

Wijs's Method.* — Reagents. — Iodine Solution. — Dissolve 13.2 grams 
of pure iodine in i liter of pure glacial acetic acid, and pass through the 
larger portion of this solution a current of carefully washed and dried 
chlorine gas f until the solution is practically decolorized. Finally add 
enough of the original solution of iodine in acetic acid to restore the 
iodine color, so that there is a slight excess of iodine. 

Hunt's Modified Iodine Solution. — Dissolve 10 grams of iodine tri- 
chloride in I liter of pure glacial acetic acid, and finally add and dissolve 
10.8 grams of pure iodine. 

Other Reagents, as in the Hiibl and Hanus methods. 

Method 0} Procedure. — Proceed as in the Hanus method, observing the 
same precautions, the only difference being in the use of the Wijs iodine 
reagent. 

Wijs recommends the following periods of time for absorption of 
the iodine in the case of various oils: For non-drying oils and fats, such 
as peanut and olive oil,t fifteen minutes; for semi-drying oils, such as 

* Ber. d. chem. Ges., 31 (i8g8), p. 750. 

t The chlorine is conveniently prepared by treatment of bleaching powder with dilute 
sulphuric acid, using gentle heat, and washing the gas by passing through strong sulphuric 
acid. 

t For butter, oleo oil, lard oil, and cocoanut oil, fifteen minutes is sulEcient. 



EDIBLE OILS AND FATS. 



for dtying 



cottonseed, rape, sesame, com, and mustard, thirty minutes; 
oils, such as sunflower and poppyseed, one hour. 

The Bromine Index or Bromine Absorption Number. — The measure 
of the amount of bromine absorbed by tlie oils and fats is a useful factor. 
By the bromine inde.x is understood the weight of bromine which is 
absorbed by i gram of a given oil. The bromine inde.x of various oils 
has been determined as follows:* 





Bromine Index. 


Observer. 


Poppyseed 


0.835 
0.763 
0.69s 
0.645 
0.632 
0-530 

0.500 to 0.544 


Levallois 

Girard 

Levallois 

Girard 
Levallois 


Mustard 




Cottonseed 




Peanut. ... 

Olive 


1 



Method oj Levallois. — Five grams of the oil are saponified with alcoholic 
potash in a 50-cc. graduated flask by the aid of a gentle heat. At the end 
of the saponification and after cooling, the flask is filled to the mark with 
alcohol, and, after shaking, 5 cc. are removed by means of a pipette and 
transferred to a flask. A slight excess of hydrocliloric acid is added 
to set free the fatty acids, and from a burette a standardized solution 
of bromine water is run in till with constant shaking a permanent yellow 
color persists. The bromine is previously standardized with potassium 
iodide and sodium thiosulphate. The weight of bromine fi.xed by i gram 
of the fat is then calculated. 

Mill's Method. — Modified.^ — Dissolve o.i gram of the filtered and 
dried fat in 50 cc. of carbon tetrachloride or chloroform in a loo-cc. stop- 
pered bottle. From a burette a standard solution of bromine in carbon 
tetrachloride, approximately tenth-normal (8 grams to a liter), is slowly 
added to the oil solution till, after fifteen minutes, a permanent coloration 
remains. The amount of bromine absorbed is calculated by comparing 
witli the color similarly produced in a blank experiment, or an excess 
of bromine solution may be run in and the solution titrated back with a 
standard solution of thiosulphate, using potassium iodide and starch. 

Thermal Tests. — The rise in temperature produced by the action 
of certain reagents on various oils and 'fats, when applied in a defi- 
nite manner, has been found to be of considerable value, especially in the 
case of sulphuric acid and of bromine. 

* Villiers et Collin, Les Substances Alimentaires, p. 680- 
t ."Mien, Commercial Org. Analysis, II, part i, p. 63. 



386 FOOD INSPECTION AND AN/t LYSIS. 

The Maumen^ Test,* or thermal reaction with sulphuric acid, is most 
readily carried out in a beaker of say 150 cc. capacity, which is set into a 
larger beaker or vessel of any kind, the space between the two being packed 
with felt or cotton waste. The inner beaker is removed, and into it is 
weighed 50 grams of the oil. It is then replaced and the packing adjusted, 
if necessary, after which the temperature of the oil is noted with a ther- 
mometer. From a burette containing the strongest sulphuric acid of 
the same temperature as the oil, 10 cc. are run into the beaker, at the 
same time stirring the mixture of acid and oil with the thermometer. 
The temperature rises somewhat rapidly, and remains for an appreciable 
time at its maximum point, which should be noted. The difference 
in degrees centigrade between the initial temperature of the oil and the 
maximum temperature of the mixture expresses the Maumen6 number. 

With certain oils, as cottonseed, considerable frothing ensues when 
concentrated acid is employed, making an accurate determination of the 
Maumene number somewhat difficult. In this case it is better to employ 
a somewhat weaker acid, and to express results in terms of what is called 
the "specific temperature reaction." This is the result obtained by 
dividing the rise of temperature in the case of the oil by the rise of 
temperature in the case of water, using the same strength of acid, and 
multiplying the quotient by 100. Indeed, it is of importance in all 
cases to compare results on oils with those obtained by carrying out 
the same test on water. 

Bromination Test. — This test depends upon the avidity with which 
the oils and fats absorb bromine, the rise in temperature caused by the 
reaction being measured in this case rather than the actual amount of 
bromine absorbed, as in the case of the iodine absorplion. Indeed, there 
is such a close relation between the iodine number and the heat of 
bromination, that when one is determined the other may be calculated 
quite closely by muUiplying by a factor. In view of the fact that the 
heat of bromination is much more readily determined than the iodine 
number, it is often convenient to calculate the latter from the former, 
the result in the case of the edible oils and fats being quite sure to fall 
within the limits of variation of the iodine number of different oils of the 
same class. The bromination test was devised by Hehner and Mitchell,! 
who employed a vacuum jacketed tube for a calorimeter in which to 
make the test. Various modifications have been suggested both in the 

* Maumene, Compt. Rend., XXXV (1852), p. 572, 
t Analyst, XX (1895), p. 146. 



EDIBLE OILS AND FATS. 



387 



apparatus employed and in the manner of diluting the oil and 
applying the reagent. The calorimeter employed by Gill and Hatch,* 
Fig. 89, is conveniently made and is very satisfactory. It consists of a 
long, narrovir, flat-bottomed tube, held by a cork in a small beaker, in 
such a manner that it is surrounded by an air jacket. The small beaker 
is set into one of larger size, the space between the two being packed with 
cotton waste. Five grams of the oil or fat are dissolved in 25 cc. 





Fig. Sg. Fio. 90. 

Fig. 8g. — Gill and Hatch's Calorimeter for the Bromination Test with Oils, 
Fig. 90. — Wiley's Pipette for Measuring Bromine in Chloroform. 

of chloroform or carbon tetrachloride, and 5 cc. of this solution 
(containing i gram of the oil) are transferred by a pipette to the 
inner tube of the above calorimeter, being careful not to let it flow 
down the sides of the tube. The temperature of the oil is then taken 
by a thermometer graduated to 0.2°. The Ijromine reagent, which 
should be freshly prepared, is made up by measuring from a burette 
one part by volume of bromine into four parts of chloroform or carbon 
tetrachloride. The reagent is transferred to a measuring- flask devised 
by Wiley,t consisting of a side-necked filter-flask provided with a per- 



* Jour. Am. Chem. Soc, XXI (iSgg), p. 27. Gill, Oil Analysis, p. 50. 
t Jour. Am. Chem. Soc, XVIII (i8g6), p. 378. 



388 



FOOD INSPECTION AND ANALYSIS. 



forated rubber stopper into which the stem of a 5-cc. pipette is fitted, 
Fig. 90. A bulb on the sidc-ncck serves to fill the pipette. This pipette, 
filled to the mark with the bromine reagent (which should be at the same 
temperature as the oil solution in the calorimeter), is first covered bv the 
finger and removed, and its contents of 5 cc. allowed to flow down the 
sides of the inner tube of the calorimeter and mingle with the oil without 
stirring. The rise in temperature is very quick, and the highest point 
is noted. The difference between the highest and the initial temperature 
constitutes the heat-of-bromination number. 

This number, in the case of Gill and Hatch's calorimeter, is somewhat 
lower than when a vacuum jacketed tube is employed, and differs some- 
what with the diluent of the oil and bromine. In spite of these variations 
and that due to the personal equation, concordant results may be obtained 
with the vaiious oils, when the method is carried out under precisely the 
same conditions. The analyst should carefully work out the test several 
times with a particular oil till the results agree, and should then with 
equal care determine the iodine number of the same oil. The iodine 
number, divided by the heat-of-bromination number, gives the factor 
which is to be employed under the same conditions for calculating one 
constant from the other. In the case of Hehner and Mitchell's work 
with the vacuum tube, measuring i cc. of undiluted bromine into i gram 
of oil dissolved in 10 cc. of chloroform, it was found that the factor to 
be used in calculating the iodine number was 5.5. 

The following are some of the results on edible oils obtained by Hehner 
and Mitchell: 



Oil. 

Lard 

Butter 

Olive oil 

Corn oil 

Cottonseed oil 



Heat of 
Bromination. 



Iodine 
Number. 



Calculated 
Iodine Number. 



10.6 
6.6 

15 

21-5 

19.4 



57-15 
37-07 
80.76 

122 
107.13 



58-3 
36.3 

82. 5 

IlS. 2 
106.7 



As in the case of the Maumene test with sulphuric acid (wherein 
llie rise in tem'perature of sulphuric acid and water is taken as a standard), 
it is convenient to employ some standard for the bromination test, whereby 
varying results due to difference in apparatus, etc., may be compared. 

In this case Gill and Hatch found that sublimed camphor may be 
prepared sufficiently pure to be used for such a standard. Applying the 
bromination test with their calorimeter, as above described, to 5 cc. of a 



EDIBLE OILS AND FATS. 



389 



solution of 7J grams of camphor in 25 cc. of carbon tetrachloride, an average 
rise in temperature of 4.2° was obtained, and the specific temperature 
reaction is calculated for each oil by dividing the heat of bromination 
by this number. Furthermore, by dividing the iodine number of several 
oils by this specific temperature reaction, the factor to be employed for 
the calculation of the iodine number was found to be 17.18, as in the fol- 
lowing cases : * 





Specific Tem- 


Iodine Number. 


Oil. 


perature 
Reaction. 


Calculated. 


Found. 


Prime lard 


3-7°5 
4.oq6 
4.762 
5.667 
6.381 


63.8 

70-3 
81.8 

97-3 
109.5 


63.8 

73-9 
82.0 




Olive 




103.0 
107.8 


Com 





TH£ RefrACTOMETER. — Various forms of refractometer are used in 
fat and oil analysis. Thus the Ahhe refractometer, more fully described 
on page 397, requires only one or two drops of the oil to be examined, and 
reads the index of refraction directly, using ordinary, white light. 

The Puljrich is used with the sodium light, and requires a larger 
amount of oil than the Abbe, the oil or melted fat being held in a cylinder 
above the prism. The scale reading is in angular degrees, from which 
the inde.x of refraction is calculated by a formula or from a table. The 
instrument is provided with a temperature-controlling apparatus. 

In the Armigat and Jean or oleo-rejractometer, an outer and an inner 
cylinder are respectively filled with an oil of known value or purity, and 
with the oil to be examined. By the comparative displacement to the 
right or left of a beam of white light passing through both cylinders, the 
displacement being read in degrees on an arbitrarj' scale, the refraction 
of an oil may be measured. Two oils may thus be readily compared 
under the same conditions, one of known puricy, for example, with a 
doubtful sample of the same kind. 

The bulyro-rejractometer and the Wollny milk jal refractometer are, 
as their names imply, instruments primarily intended for more restricted 
fields of work than the foregoing. They involve the same principle as the 
Abb^, but are simpler in construction and have arbitrar}- scales. 

Unless such widely varying substances as the waxes and the essential 
oils are to be studied, the Zeiss butyro-refractometer, though primarily 
* Gill, Oil Analysis, p. 128. 



39° 



FOOD INSPECTION AND ANALYSIS. 



intended for the examination of butter and lard, is by far the most useful 
and convenient form of instrument for the food laboratory, being equally 
well adapted for examining all the common edible oils and fats. 

The Zeiss Butyro-refractometer. — This instrument (shown in Fig. 
91) is so constructed that the degree of refraction of a beam of light, 
which passes obliquely through a thin film of the fat, is read on an arbi- 




FiG. 91. — The Zeiss ButjTO-refractometer. 

trar}' scale of sufficient extent to cover the widest limits of deviation 
possible for butter fat and oleomargarine under ordinary temperatures. 
The graduation is in divisions from i to 100, covering a variation in 
refractive indices of from 1.4220 to 1.4895. A and B are the two hinged 
hollow portions of the prism casing of the instrument, so arranged that 
when closed together the melted fat is held in a film of sufficient thickness 
between the two opposed transparent prism surfaces, the beam of light, 
either diffused daylight or lamplight, being reflected through it by means 
of the mirror J. The transparent scale is within the telescope tube at 
the height indicated by G. 



EDIBLE OILS AND FATS. 39^ 

The refractometer is connected to any kind of heating arrangement, 
which admits of warm water being transmitted through the prism casing, 
in at D and out at E. A simple arrangement, which suffices for all 
ordinary cases, may expeditiously be improvised in the following maimer: 
Fill a vessel of say 2 gallons capacity with water of 40° to 50° C. Into 
this vessel dip the free end of an india-rubber tube slipped over the nozzle 
D and let the vessel be placed at a height of about one-half or one yard 
above the refactometer. Then it will be seen that suction at a tube 
attached to E will cause the warm water to flow through the prism casing 
by the action of the siphon arrangement. By means of -a pinch clip the 
velocity of the water may be regulated at will. The waste water 
may be allowed to flow into a second vessel and, provided its tem- 
perature docs not fall below 30°, it may be used for replenishing the 
upper vessel. 

When working with solid fats, a temperature must be maintained 
by the heated water well above the melting-point of the fat. With 
liquid oils no heater is necessary, as determinations may be made at 
room temperature, but it is advisable in all cases to have a constant stream 
of water passing through the water jacket, which may be done by directly 
connecting it with the water faucet in the case of oils, since, without such 
precautions to insure even temperature, disturbing variations are liable 
to occur, due to the warming of the prisms by the manipulation of clean- 
ing, etc. 

Refractometer Heater. — ^A regular heater, shown in Fig. 92, is furnished 
by the manufacturers, capable of supplying a current of water of approx- 
imately constant temperature, and will be found of great convenience when 
the instrument is to be used constantly, especially with the solid fats. 

A supply reservoir A is secured to the wall and is connected by means 
of a rubber inlet tube G to the water faucet C. The reservoir is provided 
with a waste overflow pipe and with an outlet tube D, the flow through 
the latter being regulated by the cock H. The tube D leads to the spiral 
heater HS, which is heated by a Bunsen burner. From the heater the 
tube E conducts the warm water tlirough the refractometer, from which 
it flows through the tube F, either directly into the sink, or into the inter- 
mediate vessel B. The temperature of the water is regulated by adjust- 
ing the cock H, and the height of the flame of the Bunsen burner. 

Manipulation of the Butyro-refractometer. — The prism casing is first 
opened by giving about half a turn to the right to the pin F, Fig. gi, 
until it meets with a stop. Then simply turn the half B of the prism 



392 



FOOD INSPECTION AND ANALYSIS. 



casing aside. Pillar H holds B in the position shown in Fig. 91. The 
prism and metallic surfaces must now be cleaned with the greatest care, 
the best means for this purpose being soft linen, moistened with a little 
alcohol or benzine. 

If the sample to be examined is a solid fat, maintain the temperature 
above the melting-pointy and apply by a glass rod a drop or two of the 
clear melted fat (filtered if turbid) to the surface of the prism contained 
in the casing B. For this purpose the apparatus should be raised with 



la (S\ 




Fig. 92. — The Zeiss Heating Apparatus for all Forms of Refractometer. Shown in the 
cut in connection with the Pulfrich refractometer. 

the left hand so as to place the prism surface in a horizontal position. 
A liquid oil is directly applied in the same manner without preliminary 
precautions as to heating. Now press B against A, and place F by 
turning it in the opposite direction, in its original position; thereby B 
is prevented from falling back, and both prism surfaces are kept in close 
contact. Place the instrument again upon its sole plate. 

While looking into the telescope, give the mirror J such a position as 
to render the critical line, which separates the bright left part of the field 
from the dark right part, distinctly visible. It may aiso be necessary 
to move or turn the instrument about a little. First it will be necessary 
to ascertain whether the space between the prism surfaces be uniformly 
filled with oil or fat, failing which the critical line will not be distinct. 
For this purpose examine the rectangular image of the prism surface 
formed about i cm. above the ocular with a hand magnifier or with the 



EDIBLE OILS AND FATS. 



393 



naked eye, placing the latter at its proper distance from the ocular. 
Finally adjust the movable front part of the ocular so that the scale 
becomes clearly visible. 

By allowing a current of water of constant temperature to flow through 
the apparatus some time previous to the taking of the reading, the at first 
somewhat hazy critical line approaches in a short time, generally after a 
minute, a fixed position, and quickly attains its greatest distinctness. 
When this point has been reached, note the appearance of the critical 
line (i.e., whether colorless or colored, and in the latter case of what color); 
also note the position of the critical hne on the centesimal scale, which 
admits of the tenth divisions being conveniently estimated; at the same 
time read the position of the thermometer. 

Testing the Adjustment oj the Ocular Scale. — It is imperative that 
the adjustment of the instrument be tested periodically, and in particular 
when it is being used for the first time. This may be done by means 
of the standard fluid supplied with the instrument, the critical line of 
which is approximately colorless, and must occupy the following positions 
in the scale. 



Temper- 


Scale 


Temper- 


Scale 


Temper- 


Scale 


Temper- 


Scale 


ature. 


Division. 


ature. 


Division. 


ature. 


Division. 


ature. 


Division. 


30= 


68.1 


2';° 


71.2 


20° 


74-3 


15° 


77-3 


29= 


68.7 


24° 


71.8 


19° 


74-9 


14° 


77-9 


28° 


69.3 


23° 


72-4 


18° 


75-5 


13° 


78. 6 


27° 


70.0 


22° 


73-0 


17° 


76.1 


12° 


79.2 


26° 


70.6 


21° 


73-6 


i 16° 


76.7 


11° 


79-8 


25 = 


71.2 


20° 


74-3 


15° 


77-3 


10° 


80.4 



The fractional parts of a degree can accordingly easily be brought 
into calculation (0.1=0.06 scale div.). Deviations of i to 2 decimals 
of the scale divisions are of no consequence, and are in most cases due 
to inexact determinations of temperature. Should, however, careful 
tests resuk in the discovery of greater deviations, readjustment of the 
scale will be necessary, which may be effected by means of a watch-key 
supplied with the instrument, in accordance with the values given in 
the above table. The watch-key is inserted at G in Fig. gi, and by its 
means the position of the objective, and therefore that of the critical line 
with respect to the scale may be altered. 

Transformation of Scale Divisions into Indices oj Rcjraction. — The 
following table, adapted from that of Pulfrich, enables one to convert 
scale readings on the butyro-refractometer into mdices of refraction, n^, 
and vice versa: 



394 



FOOD INSPECTION AND ANALYSIS. 



EQUIVALENTS OF INDICES OF REFRACTION. AND BUTYRO-REFRAC- 

TOMETER READINGS. 



Refrac- 








Fuurth Dec 


imal of K 


D . 








tive 






















Index. 






















"A 





1 


2 


3 


* 


5 


6 


7 


8 


9 










SCALE READINGS 










1.422 


0.0 


o.r 


0.2 


0-4 


0-5 


0.6 


0.7 


0.9 


I.O 


I.I 


1.42,^ 


1.2 


1-4 


1-5 


1.6 


1-7 


1-9 


2.0 


2.1 


2.2 


2.4 


1.424 


2-5 


2.6 


2.7 


2.8 


3-0 


3-1 


3-2 


3-3 


3-5 


3-6 


1.425 


3-7 


3-8 


4.0 


4-1 


4.2 


4-3 


4-5 


4.6 


4-7 


4.8 


1.426 


5-° 


5-1 


5-2 


5-4 


5-5 


=;.6 


5-7 


5-9 


6.0 


6.1 


1.427 


6.2 


6.4 


6-5 


6.6 


6.8 


6-9 


7-0 


7-1 


7.2 


7-4 


1.428 


7-5 


7-6 


7-7 


7-9 


8.0 


8.1 


8.2 


8.4 


8-5 


8.6 


1.429 


8-7 


8.Q 


9.0 


9.1 


9-2 


9-4 


9-5 


9.6 


9-8 


9-9 


1.43° 


10. 


10. 1 


10-3 


10.4 


10-5 


I0.6 


10.7 


10.9 


II. 


II. I 


I-431 


11-3 


II. 4 


11-5 


II. 6 


II. 8 


II. 9 


12.0 


12.2 


12.3 


12.4 


1-432 


12.5 


12.7 


12.8 


12.9 


13-0 


13-2 


13-3 


13-S 


13-6 


13-7 


1-433 


13-8 


14.0 


14-1 


14.2 


14-4 


14-5 


14.6 


14-7 


14-9 


15-0 


1-434 


15 -I 


1^-3 


15-4 


15-5 


15-6 


15-8 


15-9 


16.0 


16.2 


16.3 


1-435 


16.4 


16.6 


16.7 


16.8 


17-0 


17. 1 


17-2 


17-4 


17-5 


17.6 


1-436 


17-8 


17.9 


18.0 


18.2 


18.3 


18.4 


18-5 


18.7 


18. S 


18.9 


1-437 


19- 1 


19.2 


19-3 


19-5 


19.6 


19-7 


19-8 


20.0 


20. 1 


20.3 


1-438 


20.4 


20.5 


20.6 


20.8 


20.9 


21. 1 


21.2 


21-3 


21.4 


21.6 


1-439 


21.7 


21.8 


22.0 


22.1 


22.2 


22.4 


22.5 


22.6 


22.7 


22.9 


1.440 


23.0 


23.2 


23-3 


23-4 


23-5 


2^7 


23.8 


23-9 


24-1 


24.2 


1. 441 


24.3 


24-5 


24.6 


24-7 


24-8 


25.0 


25-1 


25.2 


25-4 


25-5 


1.442 


25.6 


25.8 


25-9 


26.1 


26.2 


26.3 


26.5 


26.6 


26.7 


26.9 


1.443 


27.0 


27.1 


27-3 


27.4 


27-5 


27-7 


27.8 


27.9 


28.1 


28.2 


1.444 


28.3 


2S-5 


28.6 


28.7 


28.9 


29.0 


29.2 


29-3 


29-4 


29.6 


1-445 


29.7 


29.9 


30.0 


30.1 


30.3 


30-4 


30.6 


30.7 


30-8 


3°-9 


1.446 


31-1 


31.2 


31-4 


31-5 


31.6 


31.8 


31-9 


32-1 


32-2 


32-3 


1-447 


32-5 


32.6 


:2.8 


32-9 


33-0 


33-2 


33-3 


33-5 


33-6 


33-7 


1-448 


33-9 


34-0 


34-2 


34-3 


34-4 


34.6 


34-7 


34-9 


35-0 


35-1 


1-449 


35-3 


35-4 


35-6 


35-7 


35-8 


36.0 


36.1 


36-3 


36-4 


36.5 


1-450 


36-7 


36.8 


37-0 


37-1 


37-2 


37-4 


37-5 


37-7 


37-8 


37-9 


1-/151 


38.1 


38-2 


38-3 


38-5 


38.6 


38.7 


38-9 


39-0 


39-2 


39-3 


1-452 


39-5 


39-6 


39-7 


39-9 


40.0 


40.1 


40-3 


40-4 


40.6 


40.7 


I-45S 


40.9 


41.0 


41-1 


41-3 


41.4 


41-5 


41-7 


41.8 


42.0 


42.1 


I -454 


42.3 


42.4 


42-S 


42-7 


42.8 


43-0 


43-1 


43-3 


43-4 


43-6 


1-455 


43-7 


43-9 


44.0 


44.2 


44-3 


44-4 


44-6 


44-7 


44-9 


4S-0 


1-456 


45-2 


45-3 


45-5 


45-6 


45-7 


45-9 


46.0 


46.2 


46-3 


46.4 


1-457 


46.6 


46.7 


46.9 


47.0 


47.2 


47-3 


47-5 


47-6 


47-7 


47-9 


1-458 


48.0 


48.2 


48-3 


48.5 


48.6 


48.8 


48.9 


49-1 


49.2 


49 4 


1-459 


49-5 


49-7 


49-8 


50.0 


50-1 


50.2 


50-4 


50.S 


50.7 


50.8 


1.460 


51-° 


51-1 


51-3 


51-4 


51.6 


51-7 


51-9 


52-0 


52-2 


52-3 


1. 461 


52-5 


52-7 


52.8 


53-0 


53-1 


53-3 


53-4 


53-6 


53-7 


53-9 


1.462 


54-0 


54-2 


54-3 


54-5 


54.6 


54-8 


55 -o 


55-1 


55-3 


55-4 


1.463 


55-6 


55-7 


55-9 


56.0 


56-2 


56-3 


56-5 


56.6 


56.8 


56-9 


1-464 


57-1 


57-3 


57-4 


57-6 


57-7 


57-9 


58.0 


58.2 


58.3 


58-5 


1-465 


58.6 


58.8 


58-9 


59-1 


59-2 


59-4 


59-5 


59-7 


59-8 


60.0 


I -466 


60.2 


60. ■>, 


60- 5 


60.6 


60.8 


60.9 


61. 1 


61-2 


61.4 


61.5 


1.467 


61.7 


61.8 


62.0 


62.2 


62.3 


62.5 


62.6 


62.8 


62.9 


63.1 


1.468 


63.2 


63-4 


63.5 


63-7 


63-8 


64.0 


64.2 


64.3 


64.5 


64.7 


1.469 


64.8 


65.0 


65.1 


65-3 


65-4 


65.6 


65-7 


65-9 


66.1 


66.2 



EDIBLE OILS AND FATS. 



395 



EQUIVALENTS OF INDICES OF REFRACTION AND 
TOMETER READINGS— (Conftnweii). 



BUTYRO-REFRAC- 



Refrac- 
tive 








Fourth Decimal of «i)_ 








Index, 






















"D. 





1 


2 


3 


4 


5 


6 


7 


8 


9 










SCALE READINGS 










1.470 


66.4 


66.5 


66.7 


66.8 


67.0 


67.2 


67-3 


67-5 


67.7 


67.8 


1. 471 


68.0 


68.1 


68.3 


68.4 


68.6 


68. 7 


68.9 


69.1 


69 


2 


69.4 


1.472 


69-S 


69.7 


69.9 


70.0 


70.2 


70-3 


70-5 


70-7 


70 


8 


71.0 


1-473 


71. 1 


71-3 


71-4 


71.6 


71.8 


71-9 


72.1 


72.2 


72 


4 


72-5 


1-474 


72.7 


72.9 


73-° 


73-2 


73-3 


73-5 


73-7 


73-8 


74 





74-1 


I -475 


74.3 


74-5 


74.6 


74.8 


75-° 


75-1 


75-3 


75-5 


75 


6 


75-8 


1.476 


76.0 


76.1 


76.3 


76-5 


76.7 


76.8 


77.0 


77-2 


77 


3 


77-5 


1-477 


77-7 


77-9 


78.1 


78.2 


78-4 


78.6 


78.7 


78-9 


79 


I 


79.2 


1.478 


79-4 


79-6 


79-8 


80.0 


80.1 


80.3 


80.5 


80.6 


80 


8 


81.0 


1.479 


81.2 


81.3 


81-5 


81.7 


81.9 


82.0 


82.2 


82.4 


82 


5 


82.7 


1.480 


82.9 


83-x 


83.2 


83.4 


83.6 


83.8 


83-9 


84.1 


84 


3 


84-5 


1. 481 


84.6 


84.8 


85.0 


85-2 


85-3 


85-5 


85-7 


85-9 


86 





86.2 


1.482 


86.4 


86.6 


86.7 


86.9 


87.1 


87-3 


87-5 


87.6 


87 


8 


88.0 


1-483 


88.2 


88.3 


88.5 


88.7 


88.9 


89.1 


89.2 


89-4 


89 


6 


89.8 


1.484 


go.o 


90.2 


90-3 


9°-5 


90.7 


90.9 


91. 1 


91.2 


91 


4 


91.6 


1.48s 


91.8 


92.0 


92«I 


92-3 


92-S 


92.7 


92.9 


93-0 


93 


2 


93-4 


1.486 


93-6 


93-8 


94.0 


94-1 


94-3 


94-5 


94-7 


94-8 


95 





95-2 


1-487 


95-4 


95-6 


95-8 


96.0 


96.1 


96.3 


96.6 


96-7 


96 


9 


97.0 


1.488 


97.2 


97-4 


97-6 


97-8 


98.0 


98.1 


98-3 


98-5 


98 


7 


98.9 


1.489 


99-1 


99.2 


99-4 


99-6 


99-8 


100. 













The Critical Line. — It should be remembered that the instrument is 
primarily intended for use with butter, and that the prisms are so con- 
structed that the critical line of pure butter is colorless, while various other 
fats and oils, notably oleomargarine, which have greater dispersive powers 
than natural butter, show a colored critical line. Wlien too great dis- 
persion is apparent to render possible an accurate reading, or when the 
critical line presents very broad fringes, as with linseed oil, poppyseed 
oil, turpentine, etc, use a sodium light, obtained by the apphcation of 
table salt to the Bunsen gas flame, or the diffused daylight may be re- 
flected in the mirror through a flat bottle filled with a dilute solution of 
potassium bichromate, to give a yellow light. 

The advantages of the refractometer for examination of fats and 
oils consist in the convenience with which very accurate determinations 
of the refractive index may be made at any temperature between 10° and 
50° C, inclusive of thermal variations of refractive powers, and also in 
the possibility which it affords of distinguishing substances by their 
different dispersive powers, rendered visible by the different coloring 
of the critical line, a red-colored critical line being indicative of a relatively 
low dispersive power, a blue line of relatively high dispersion. 



396 






'■~i ^ N ^ - - r2 



5 J 



Id . - 



5 - 



UJ ri = 



s-i 






-=- - o 



f==^<^"^- 



tiJ 
1 *- 



Sgf- 



S 



-O— i— 3 



3 - 









4lS' 






FOOD INSPECTION /IND ANALYSIS. 

Variation oj Reading with the Temperature. — 
No definite temperature has been adopted as a 
standard for readings of this instrument, but it 
is easy to reduce readings at any temperature to 
terms of any other temperature for purposes of 
comparison. While the change in index of re- 
fraction for 1° C. is the same whatever the 
temperature, as Tolman and Munson have pointed 
out,* the change in scale reading per i° C. de- 
creases as the temperature increases, and varies 
slightly with different oils. For correcting read- 
ing R' at a temperature T' to a reading R at 
temperature T, their formula is R = R' — X(T — 
T'), X being the change in scale reading due to 
change of i° C. in temperature. 

For butter, oleomargarine, beef tallow, lard, 
and other fats reading from 40° to 50° or there- 
abouts on the scale, X = o.55. For oils reading 
between 60° and 70°, like olive, mustard, rapeseed, 
cottonseed, peanut,etc.,X = o.58, and for oils read- 
ing between 70° and 80°, like corn oil, X = o.62. 

The slide rule, showoi in Fig. 93, for use with 
the refractometer, has been jointly devised by H. 
C. Lythgoe and the writer, to render unnecessary 
the use of tables or formulas. The extreme upper 
and lower scale divisions indicate indices of re- 
fraction, and adjacent to these are the scale 
divisions indicating readings on the butyro- 
refractometer. By comparison, therefore, the 
values of either the Abbe or the butyro scale 
may be readily ascertained in terms of the 
other. 

The sliding scale, expressing temperature 
readings in degrees centigrade, is intended to be 
used in connection with the adjacent scale of 
butyro-refractometer readings, to readily express 
the butyro-scale reading of any fat or oil taken 
at a given temperature, in terms of that at any 
other temperature. This is frequently convenient 



3_rJ 



Fio. 



93. — Comparative 

fractometer Scale. 



Re- 



* Jour. Am. Chem. Soc, XXIV, p. 755. 



EDIBLE OILS AND FATS. 



397 



in comparing the work of various observers, where diflerent temperatures 
have been employed. 

The correction for change in n^, on the scale is 0.000365 for 1° C, 
being based on the experimental work of Tolman, Long, Proctor, Lythgoe, 
and the author. 

The table on pp. 398, 399 is useful as showing readings on the butyro- 
refractomcter of all the edible oils and fats at various temperatures.* 

The Abbe Refractometer, Fig. 94, has a much wider range in reading 




Fig. 94. — The Abbe Refractometer with Temperature-controlled Prisms. 

than either the butyro or the WoUny instruments already described, read- 
ing as it does to the fourth decimal between the limits of 1.3 and 1.7 in 
indices of refraction. The equivalent readings of the Wollny milk fat 
refractometer, in indices of refraction, range from 1.3332 to 1.4220, while 
those of the butyro-instrument run from 1.4220 to 1.4895. The Abbe 
instrument is thus necessar}' for use with the high-refracting essential 



* Lythgoe, Tech. Quarterly. 



398 



FOOD INSPECTION AND ANALYSIS. 



CALCULATED READINGS ON BUTYRO-REFRACTOMETER OF EDIBLE 

OILS AND FATS. 



Temp. 
C. 



45-° 

44-5 
44.0 

43-5 
43 -o 
42-5 

42.0 

41-5 
41.0 

40.5 
40.0 

39-5 
39-0 
38-5 
38.0 

37-5 

37-° 
36-5 
36.0 

35-5 
35-° 

34-5 
34-0 
33-5 
33-0 



32.0 
31-5 
31-° 
3°-5 
30.0 

29-5 
29.0 
2S.5 
28.0 

27-5 

27.0 
26.5 
26.0 
25-5 



Cocoanut 
OU. 



31.6 



31 
32 
32 
32 
52 

ij, 
33 
34 
34 

34 
34 
35 
35 
35 

35 
36 
36 
36 
36 

37 
37 
37 
37 



38 
38 
38 
39 
39 

39 
40 
40 
40 
40 

41 
41 
41 
41 
42 



Butter.* 



41-5 



41. 
42. 
42. 
42. 
42. 



43-1 
43-4 
43-7 
43-9 
44-2 

44-5 
44-8 
45-° 
45-3 
45-6 

45-9 
46.1 
46.4 
46.7 
47-° 

47.2 

47-5 
47-8 
48.1 
48.3 

48.6 
48-9 
49-2 
49-5 
49-8 

50.0 
50-3 
5° -5 
50.8 

51-1 

51-4 
51.6 

51-9 
52.2 

52-5 



Beef 

Stearin . 



41-9 

42.2 
42.4 
42.6 
42-9 
43-2 

43-5 
43-7 
44.0 

44-2 
44-5 



Cacao 
Butter. 



43-7 

44-0 
44-2 
44-5 
44-8 
45-0 

45-3 
45-6 
45-9 
46.1 
46.4 

46.6 
46.8 
47-1 
47-4 
47.6 

47-9 
48.2 

48,5 
48.7 
49-° 



Beef 
Tallow. 



44.1 



45-'' 
45-8 
46. 1 
46.3 
46.6 



46.8 
47-1 
47-4 
.17.6 
47.8 

48.1 

48.3 
48.6 
48.8 
49.1 



Lard 
Stearin. 



44-9 



45- 
45- 
45- 
46. 
46. 



46.5 
46.8 
47-° 
47-3 
47-6 

47-8 
48.1 
48.4 
48.6 
48-9 

49.2 
49-4 
49-7 
50.0 
50.2 



Beef 


Oleo. 


45 -o 


45-3 


45-6 


45-9 


46.1 


46.4 


46.7 


47-° 


47-3 


47-6 


47-8 


48.1 


48.4 


48-7 


48.9 


49.2 


49-5 


49-8 


50.0 


50-3 


50.6 


5° -9 


51.2 


5 '-5 


51-7 


52.0 


52-3 


52-6 


52-8 


53-1 


53-4 


53-7 


53-9 


54-1 


54-4 


54-7 


55-° 


55-2 


55-5 


6:;. 8 


66.1 



Lard.t 



48.2 



48 
49 
49 
49 

49 

5° 
5° 
5° 
51 

51 

51 
51 
52 
52 

52 
53 
53 
53 
53 

54 
54 
54 
55 
55 

55 
55 
56 
•;6, 

56 

57 
57 
57 
57 
58 

58 
58 
59 
59 
59 



Lard 
Oil. 



51-6 

51-8 
52-1 
52-4 
52.6 
52.8 

53-1 
53-4 
53-7 
54.0 

54-2 

54-5 
54-7 
55-° 
55-3 
55-6 

55-9 
56.1 
56-4 
56-7 
57-° 

57-2 
57-5 
57-8 
58-1 
58.3 

58.6 

58-9 
59-2 
59-5 
59-8 



* Butter reatlings by Zeiss, 
t Lard readings by Hefelman ■> 



EDIBLE OILS AND FATS. 



399 



CALCULATED READINGS— (Con/ZHueii). 



Temp. 
C. 


Olive 
OU. 


Peanut 
OU. 


Cotton- 
seed 
OU. 


Rape- 
seed 
Oil. 


Sesame 
OU. 


Yellow 

Mustard 
OU. 


Black 

Mustard 
OU. 


Sun- 
flower 
OU. 


Com 
OU. 


Poppy- 
seed 
Oil. 


35-° 


S7-0 


59-8 


61.8 


62.1 


62.3 


63.0 


64.2 


64-5 


65.0 


65-5 


34-5 


57-2 


60.0 


62.1 


62.4 


62.5 


(>i-i 


64-5 


64.8 


65-3 


65.8 


34-0 


57-4 


60.3 


62.3 


62.7 


62.8 


63.6 


64.8 


65.1 


65.6 


66.1 


33-5 


57-7 


60.6 


62.5 


63.0 


63.1 


63-9 


65.1 


65.4 


65-9 


66.4 


33-° 


sS.o 


60.9 


62.8 


63-3 


63-4 


64.1 


65-3 


65-7 


66.2 


66.7 


32-5 


58-3 


61. 1 


63.0 


63.6 


63-7 


64.4 


65.6 


66.0 


66.5 


67.0 


32.0 


58-S 


61.4 


63.2 


63.8 


64.0 


64.7 


65-9 


66.3 


66.8 


67-3 


31-5 


59-0 


61.7 


63.6 


64.1 


64.3 


65.0 


66.2 


66.6 


67.1 


67.6 


31.0 


59-2 


62.0 


64.0 


64.4 


64.6 


65-3 


66.5 


66.9 


67.4 


67.9 


30-5 


59-5 


62.2 


64.2 


64.7 


64.9 


65.6 


66.8 


67.2 


67-7 


68.2 


30.0 


59-9 


62.5 


64.5 


65.0 


65.1 


65.8 


67.0 


67-5 


68.0 


68.S 


29-5 


60.1 


62.8 


64.9 


65-3 


65-4 


66.1 


67-3 


47-7 


68.2 


68.7 


29.0 


60.3 


63.1 


65.1 


65.6 


65-7 


66.4 


67.6 


68.0 


68.5 


69.0 


28. s 


60.6 


63-3 


65-3 


65-9 


66.0 


66.7 


67.9 


68. 3 


68.8 


69-3 


28.0 


60.9 


63.6 


65-7 


66.1 


66.2 


66.9 


68.1 


68.6 


69.1 


69.6 


27-5 


61. 1 


63-9 


66.0 


66.4 


66.5 


67.2 


68.4 


68.9 


69.4 


69.9 


27.0 


61-5 


64.2 


66.5 


66.7 


66.8 


67.5 


68.7 


69.2 


69.7 


70.2 


26.5 


62.0 


64-4 


67.0 


67.0 


67.1 


67.8 


69.0 


69-5 


70.0 


70-5 


26.0 


62.2 


64.7 


67-3 


67-3 


67.0 


68.0 


69.2 


69.8 


70-3 


70.8 


25-5 


62.4 


65.0 


67-5 


67.6 


67.7 


68.3 


69.5 


70.1 


70.6 


71. 1 


25.0 


63.0 


65-3 


67.9 


67. 8 


67.9 


68.6 


69.8 


70.4 


70.9 


71-4 


24-5 


63-3 


65-5 


68.2 


68.1 


68.2 


68. 9 


70.1 


70.7 


71.2 


71-7 


24.0 


63.6 


65.8 


68.5 


68.4 


68.5 


69.2 


70.4 


71.0 


71-5 


72.0 


23-5 


63-9 


66.1 


68.8 


68.7 


68.8 


69-5 


70.7 


71-3 


71. 8 


72-3 


23-0 


64.2 


66.4 


69.1 


69.0 


69.1 


69.7 


70.9 


71.6 


72.1 


72.6 


22-5 


64-5 


66.6 


69.4 


69-3 


69.4 


70.0 


71.2 


71.9 


72.4 


72.9 


22.0 


64.8 


66.9 


69.7 


69.7 


69.7 


7°-3 


71-5 


72.2 


72.7 


73-2 


21-5 


65-1 


67.1 


70.0 


70.0 


70.0 


70.6 


71.8 


72-5 


73-0 


73-5 


21.0 


65.4 


67.4 


70-3 


70-3 


70-3 


70.9 


72.1 


72.8 


73-3 


73-8 


20.5 


65-7 


67.7 


70.6 


70.6 


70-5 


71.2 


72.4 


73-1 


73-6 


74-1 


20.0 


66.0 


68.0 


70.9 


70.8 


70.8 


71-4 


72.6 


73-4 


73-9 


74-4 


19-5 


66.3 


68.2 


71.2 


71. 1 


71. 1 


71.7 


72.9 


73-6 


74-1 


74-6 


19.0 


66.6 


68.5 


71-5 


71-4 


71-4 


72.0 


73-2 


73-9 


74-4 


74-9 


18.5 


66.9 


68.8 


71.8 


71.7 


71.7 


72.3 


73-5 


74-2 


74-7 


75-2 


18.0 


67.2 


69.1 


72.1 


72.0 


72.0 


72.6 


73-8 


74-5 


75-0 


75-5 


17-5 


67-5 


69-3 


72.4 


72-3 


72.3 


72.9 


74-1 


74-8 


75-3 


75-8 


17.0 


67.8 


69.6 


72.7 


72.6 


72-5 


73-1 


74-3 


75-1 


75-6 


76.1 


16. s 


68. 1 


69.9 


73-0 


72.9 


72.8 


73-4 


74.6 


75-4 


75-9 


76-4 


16.0 


68.4 


70.2 


73-3 


73-2 


73-1 


73-7 


74.9 


75-7 


76.2 


76.7 


15-5 


68.7 


70-5 


73-6 


73-5 


73-4 


74-0 


75-2 


76.0 


76-S 


77-0 


15.0 


68. 9 


70.8 


73-8 


73-8 


73-7 


74-3 


75-5 


76.3 


76.8 


77-3 



400 FOOD INSPECTION AND ANALYSIS. 

oils. Its construction is such that the prisms can withstand a higher 
heat than in the case of the butyro-refractometer, and it is hence better 
adapted for the examination of samples having a high melting-point, 
such as beeswax and paraffin. An advantage of the Abbe over the butyro 
instrument lies in the fact that the wide dispersion, inevitable when read- 
ing many of the oils on the butyro, may be entirely compensated for with 
the Abbe, and a clear sharp line be obtained. The construction of the 
prisms in relation to the heating jacket is similar in both instruments, 
and a film of the oil or fat to be examined is held in the same manner 
between the surfaces of the prisms. 

Looking through the ocular O of the Abbe, Fig. 94, the arm J, bearing 
the telescope L, is turned back and forth until the line of demarkation of 
the refracted beam passing through the oil is seen to coincide with the 
centering cross hairs. By turning the thumb screw M, the graduated 
chamber immediately below containing the compensator may be rotated 
stifficiently to entirely do away with any dispersion of the oil, thus getting 
a perfectly clear, sharp reading. 

The index of refraction is read through the telescope L on the gradu- 
ated arc S to the fourth decimal place. 

The Acetyl Value. — On heating fats with acetic anhydride they 
become '' acctylatcd" ; i.e., the hydrogen atom of their alcoholic hydroxyl 
group is exchanged for the acetic acid radicle, in accordance, for example, 
with the following reaction: 

C,,H3,(OH)COOH-f (C,H30),0 = C„H32(0,C,H30)C00H-FCHA- 

liicinoleic Acetic anhy- Acetyl-ricinoleic Acetic 

acid dride acid acid 

By the actyl value is meant the number of milligrams of potassium 
hydroxide neccssar}' to neutralize the acetic acid formed by the saponifi- 
cation of I gram of the acetylated fat. 

Lewkowitsch's method of procedure is as follows: 10 grams of the 
oil are boiled with an equal volume of acetic anhyd.ride for two hours 
in a flask with a return-flow condenser, and the mixture is then trans- 
ferred to a large beaker containing 500 cc. of water, and boiled for half 
an hour. To prevent bumping, a current of carbon dioxide is slowly 
passed through it during the boiling, introduced through a finely drawn, 
bent glass tube reaching nearly to the bottom of the beaker. The mix- 
ture on standing separates into two layers, of which the lower, or aqueous 
layer, is siphoned off, and the oily layer boiled with fresh portions of 



EDIBLE OILS AND FATS. 401 

water, which are in turn siphoned off, the operation being repeated till 
the wash water tests free from acid by litmus paper. 

The acetylated fat is then separated from the water by drj-ing at 
100° in an oven. 

From 2 to 4 grams of the acetylated fat is weighed into a flaslc, and 
saponified with alcoholic potash in precisely the same manner as for 
the determination of the saponification number. Evaporate the alcohol 
and dissolve the soap in water. One of two methods may be carried 
out for freeing the acetic acid for titration, one by distillation and the 
other by filtration. 

For the former or distillation process, acidify the aqueous solution 
of the soap with i : 10 sulphuric acid, and distill in the same way as in the 
Reichert process, excepting that in this case from 600 to 700 cc. of dis- 
tillate must be obtained, so that water should be added from time to 
time through a stoppered funnel fixed in the cork of the distilling-flask. 
The distillate should be received in a funnel with a loose cotton plug, so 
as to filter it free from insoluble acids mechanically carried over. The 
filtrate is titrated with tenth-normal sodium hydroxide, using phcnol- 
phthalein as an indicator. The number of cubic centimeters of alkali 
used is multiplied by 5.61, and the product divided by the number of 
grams of acetylated fat taken. The result is the acetyl value. 

If the filtration process is used (which is more rapid and should give 
concordant results with the distillation process), the exact amount of 
alcoholic potash used in the saponification should be accurately measured 
in carrying out the former part of the test, and the exact number of cubic 
centimeters of standard acid corresponding to the amount of alkali 
employed should be added to the aqueous soap solution. The mixture 
should be gently warmed, and the fatty acids will gather in a layer at the 
top. These are filtered off and washed, till free from acid, with boiling 
water. The filtrate is titrated with tenth-normal sodium hydroxide, and 
the acetyl value calculated as in the distillation process. 

EDIBLE OILS ARRANGED IN ORDER OF ACETYL VALUE. 

Average. 

Cottonseed oil 18.0 

Rape oil 14.7 

Poppyseed oil 13 . i 

Sesame oil ii-5 

Olive oil 10 .6 

Peanut oil 3.4 



40 2 FOOD INSPECTION AND ANALYSIS. 

The Valenta Test. — This depends upon the solubihty of the oil in 
glacial acetic acid. Pour from 3 to 5 cc. of the oil into a test-tube, and 
add an equal volume of glacial acetic acid (specific gravity 1.0562). 
Place a thermometer in the tube and warm gently till the oil goes into 
solution. Then allow the mixture to cool, and observe the temperature 
at which the solution begins to appear turbid. 

Castor oil and oil of the olive kernel are soluble in glacial acetic acid 
at ordinary temperatures, while rape and mustard seed oils are insoluble 
even in the boiling acid. 

Elaidin Test. — This is based on the conversion by nitrous oxide of 
hquid olein into the solid elaidin, a crystalline compound isomeric with 
olein, while other common glycerides remain liquid under treatment 
with this reagent. By the consistency of the final product, when sub- 
jected under certain conditions to the action of nitrous oxide, some idea 
as to the character of the oil may be gained. 

Manipulation. — -To carr}' out the test according to Pontet (modified), 
weigh 5 grams of the oil into a beaker, add 7 grams of nitric acid (specific 
gravity 1.34) and about 0.5 gram of copper wire. Place the beaker in 
water at 15° and stir thoroughly with a glass rod in such a manner as 
to make an intimate mixture of the oil and the evolved nitrous oxide gas. 
After the wire has been dissolved, add another piece of about the same 
size and again stir vigorously. Set aside for about two hours, at the end 
of which, in the case of pure olive, almond, peanut, or lard oil, it will 
have been changed into a solid white mass. 

Nearly all the seed oils, especially cottonseed and mustard, are turned 
into a pasty or buttery mass. 

Another modification of Pontet's test consists in mixing 10 grams 
of the oil, 5 grams of nitric acid (specific gravity 1.38), and i gram of 
mercury in a test-tube, shaking for three minutes and allowing to stand 
twenty minutes, when it is again shaken. 

The behavior of various oils after that time on further standing is as 

follows : 

Solidified after 

Olive oil 60 minutes 

Peanut oil 80 " 

Sesame oil 185 " 

Rape oil 185 " 

Free Fatty Acids.* — Weigh 20 grams of the oil or fat into a 150-cc. 
Erlenmeyer flask, and add 50 cc. of 95% alcohol, which has previously 

* Allen. Com. Org. Anal., 3d ed., vol. 2, pt. i, p. 105. 



EDIBLE OILS AND FATS. 40 j 

been carefully neutralized with a weak solution of sodium hydroxide, 
using phcnolphthalein as an indicator. Warm the mixture to about 60°, 
and add carefully from a burette tenth-normal sodium hydroxide (using 
the above indicator) till a pink color is produced, shaking thoroughly 
during the titration. 

The result may be reported in terms of percentage of. oleic acid (each 
cubic centimeter of tenth-normal alkali is equivalent to 0.0282 gram of 
oleic acid) or as the "acid number," by which is meant the number of 
cubic centimeters of tenth-normal alkali necessary to saturate the free 
acid in i gram of the fat or oil. 

Constants of the Free Fatty Acids. — Often much information as to 
the character of an oil or fat may be obtained by determining such con 
stants of its fatty acids as the melting- and solidifying-point, the iodine 
number, etc. 

To prepare the fatty acids for examination, saponify a quantity of the 
oil or fat with alcoholic potash, evaporate the alcohol, and dissolve the 
soap in hot water. Decompose the soap by the addition of an excess 
of hydrochloric or sulphuric acid, continuing the heating till the fatty 
acids rise in a layer to the top of the liquid, from which they may be 
removed. The melting-point, iodine number, etc., are determined as 
with the oil or fat itself. 

Solidifying-point of the Fatty Acids, or Titer Test. — Method of Dali- 
can* — Liberate the fatty acids as in the preceding sections, free from 
water by iiltration, and allow to stand over night in a porcelain dish in a 
desiccator. The mass of fatty acids is then melted and poured into a 
warm test-tube 3.5 cm. in diameter till it is about half full. The test-tube 
is then inserted into the neck of a flask, cither directly or, preferably, 
is fitted into a rubber stopper, which itself fits the flask. A delicate ther- 
mometer previously warmed is then inserted into the liquid, and the 
contents are stirred with it, taking care that it does not touch the sides, 
but is raised and lowered so that the whole is well mixed as portions of 
the mass solidify. The temperature at first falls, and the thermometer 
should be watched carefully, for, after a short time, it quickly rises a 
few tenths of a degree and remains stationary for a minute or two before 
again faUing. This stationary point is known as the solidifying-point 
or titer. 

Unsaponifiable Matter.— As will be seen by reference to the table 
on page 411, the unsaponifiable matter in pure edible oils and fats is 

* Thorpe's Dictionar)- of Applied Chemistry, vol. Ill, p. 50. 



404 FOOD INSPECTION /1ND AN/1 LYSIS. 

comparatively insignificant in amount, consisting largely of cholesterol or 
phytosterol. A high content of unsaponifiable matter is indicative of 
adulteration, pointing to the presence of mineral or coal-tar oils, or to 
paraffin. 

Determination of Unsaponifiable Matter.* — Weigh 7 to 10 grams of 
the fat or oil in a 250-cc. flask, and saponify by boiling with 25 cc. of 
alcohohc potassium hydroxide and 25 cc. of alcohol under a return- 
flow condenser. After saponification, add 30 to 40 cc. of water, and 
bring to the boiling-point. Cool and transfer the contents from the 
flask to a separatory funnel, washing out the flask first with a small amount 
of 50% alcohol, and finally with 50 cc. of petroleum ether (B.P. 4o°-7o°), 
adding both washings to the separatory funnel. Shake the latter 
thoroughly, but avoid if possible forming an emulsion. If the latter 
persists in forming, add a volume of water equal to that of the soap solu- 
tion, which will sometimes break it up. After separation of the petro- 
leum ether layer, draw off the underlying soap solution into a beaker, 
and wash the petroleum ether two or three times with 50% alcohol, which 
is drawn off and added to the soap solution. The petroleum ether is 
then run into a tared Erlenmeyer flask, and the soap solution extracted 
twice more with fresh portions of petroleum ether, washing the ether 
each time with 50% alcohol as before and then transferring the ether 
to the tared flask. The petroleum ether is then removed by placing 
the flask on the water-bath, bumping being prevented by means of a 
spiral of platinum wire weighed with the flask. Finally remove all traces 
of remaining ether by blowing hot air through the flask, or, in the absence 
of mineral oils (some of which are volatile), dry in the water-oven to con- 
stant weight, cool in a desiccator, and weigh. 

Cholesterol and Phytosterol. — These are monatomic alcohols, 
and combine with the fatty acids forming esters. Both respond to the 
same reactions, and arc separated by the same process from the oils and 
fats in which they occur. Phytosterol was long thought to be the same 
as cholesterol, and some confusion seems to have arisen from the fact 
that early %vriters purport to have found cholesterol in vegetable oils, 
when in reality the substance was phytosterol. The latter was first 
distinguished from cholesterol by Hesse, who named it. 

Cholesterol (CjeH^^O) crj'stallizes in white, nacreous, monoclinic 
laminae, having a melting-point of 145° and specific gravity 1.067. Its 
reaction is neutral, it is devoid of taste or smell, insoluble in water, sparingly 

* Honig and Spitz, Jour. Soc. Chem. Ind., 1891. p. 1039. 



EDIBLE OILS AND F.4TS. ' 4°$ 

soluble in cold, but readily soluble in boiling alcohol, and soluble in ether, 
chloroform, methyl alcohol, benzene, and oil of turpentine. It sublimes 
unchanged at 200°, but at higher temperatures decomposes. 

Commercial cholesterol is obtained from wool oil and is known as 
lanolin, being used largely in medicine as a basis for ointment. 

Cholesterol occurs also in the yolk of eggs, in many animal secretions, 
and in most animal oils and fats. 

It separates in laminated, transparent crystals from a mixture of 
2 volumes alcohol and i volume ether, and in the form of anhydrous 
needles from chloroform. 

Phytosterol (Cj6Hj^O,H20) is most abundantly found in the legu- 
minous seeds, and is prepared commercially from these, especially from 
peas and lentils. It is a constituent of most vegetable oils. 

It crystalhzes in slender, glittering plates from chloroform, ether, 
and petroleum ether, and from alcohol in tufts of needles. In solubility 
it much resembles cholesterol, but its melting-point from 132° to 134° 
is lower. 

Separation of Cholesterol and Phytosterol from Oils and Fats. — 
Method oj Kreis and Wolf.* — 50 grams of fat are boiled with 125 cc. of 
95% alcohol and 25 cc. of a 40% aqueous solution of sodium hydro.xide till 
saponitied. Evaporate off the alcohol, and dissolve the soap in 500 cc. of 
boiling water, neutralizing the excess of alkali with hydrochloric acid (spe- 
cific gravity 1.124). Add 100 cc. of a 10% solution of calcium chloride, and 
shake the flask till the calcium soap separates out, adding more calcium 
chloride if the liquid still froths after shaking. The calcium soap is 
collected on a filter of cotton cloth and pressed between filter-paper, 
after which it is boiled for an hour in 100 cc. of 95% alcohol. When 
cold, the solution is filtered, and the filtrate treated with 3 cc. of the 40% 
soda solution to saponify any remaining fat, and then evaporated to dry- 
ness. The small residue is powdered and shaken in a flask with 50 cc. 
of ether at inter\-als during an hour. The residue obtained on filtering 
and evaporating the ether is dissolved in as small as possible a volume 
of hot alcohol, and in coohng the cholesterol or phytosterol is deposited 
in firm, white crystals. 

Determination of Cholesterol and Phytosterol. — Method of Forster and 
Reichmann.-^ — 50 grams of the oil or fat are boiled for five minutes in 
a flask connected with a reflux condenser with two successive portions 

* Chem. Zeit., 1S98 (22), p. S05; Jour. Soc. Chem. Ind., 17, p. 1075. 
t Analyst, 1S97 (22), 131. 



4o6 FOOD INSPECTION AND ANALYSIS. 

of 75 cc. of 95% alcohol, and in each case the alcoholic solution is sepa- 
rated by means of a separator}' funnel. The combined alcoholic solutions 
are then boiled in a flask provided with a funnel in the neck, till one- 
fourth of the alcohol is evaporated, and then poured into an evaporating 
dish and brought to dryness. The residue is then extracted w^ith ether, 
and the ether solution is evaporated to dryness, taken up again with ether, 
filtered, evaporated once more, and dissolved in hot 95% alcohol, from 
which it is allowed to crystallize. Cholesterol or phytosterol will crys- 
tallize out under these conditions, and may be weighed. 

Distinguishing between Cholesterol and Phytosterol. — It is sometimes 
of importance to determine which of these substances is present in an 
oil, or whether indeed both occur. Confirmatory proof as to the presence 
of vegetable in animal oils may, for instance, be established by showing 
whether the unsaponifiable residue in the sample contains cholesterol or 
phytosterol or both. Hehner* has made use of this test in determining 
the presence of cottonseed oil in lard. 

The most ready means of distinguishing between cholesterol and 
phytosterol is furnished by the melting-point (cholesterol 149°, phytos- 
terol 132° to 134°) and by the marked difference between the form of the 
cr>'stals and the manner of crj'stallization of the two substances. 

Crystallization. — Bomer f has shown that if allowed to crystallize 
very slowly out of a strong alcohohc solution, preferably absolute alcohol, 
in a shallow glass, the crystalhzation in the case of cholesterol alone begins 
from the margin of the liquid and gradually extends inward toward the 
center, forming a uniformly bright, thin, colorless film over the whole 
surface. This film is best removed with a knife or spatula and pressed 
between filter-paper. The film will be seen, even megascopically, to 
be composed of large, glossy plates with a silk-like luster. After the 
removal of the first film a second will form similar to the first, but composed 
as a rule of smaller crystals. These are removed in like manner, dried 
between filters, and added to the first in a glass. After the second crop, 
the mother liquid is thro\\'n away. The crystals are then redissolved in 
absolute alcohol, and again allowed to separate out, being repeatedly 
recrystaUized till the melting-point is constant. In lard and most fats 
the crystals were found pure by Bomer after the second crystallization. 

Phytosterol is cr\-stallized with greater difficulty, especially when 
derived from seed oils, on account of the presence of pigments and other 

* Analyst, 1888 (13), 165. 

t Ziets. fiir Nahr. u. Genuss., iSqS p. 40. 



EDIBLE OILS AND FATS. 



407 



foreign matter. The first procedure is the same as above described for 
cholesterol, the crystals being allowed to separate slowly out of a solu- 
tion in absolute alcohol. Unlike cholesterol, no film is formed on the 
surface, but needles (sometimes 1 cm. in length) are gradually elim- 
inated, beginning at the margin and extending inward mostly at the 
bottom. In concentrated solutions, fine needles would be uniformly 
deposited through the liquid. These are best separated from the mother 
liquid by filtration, as they are not easily taken out with a knife. They 
may be washed on the filter with small amounts of absolute alcohol for 
microscopical examination, or repeatedly recrystallized, as in the case 
of cholesterol, till the melting-point is constant. 

Cholesterol Crystals* — When crystallized separately under above 
conditions, cholesterol crystals viewed under the microscope show generally 
rhomboidal forms of plates, as in Fig. 95, but sometimes mth a reenter- 




FlG. 95, — Cholesterol Cn'stals under the Microscope. (After Bomer.) 

ing angle. The plates are often growTi together in masses. The most 
characteristic forms are found from the first crystallization or from 
the first film removed. Sometimes quadrilateral crj'stals predominate 
among the plates, often also the other shapes shown are found most 
numerous. 

Phylosterol Crystals. — Pure phytosterol crystallizes in needles or 
narrow plates, arranged commonly in star form or in bunches. The 
most common forms are shown in Fig. 96, best conditions as to shape 
of crystals being obtained from slow crystallization, in which case the 
needles are finer and more regular. 

The crystals are commonly in the form of long, narrow plates, thin 
and slender, often pointed at both ends. Sometimes the points are 
lacking, or the ends are beveled. The more frequently they are re- 
crystallized, the larger and more varied are the crystal forms. The 
broad, hexagonal and quadrilateral plates showm are products of re- 



* Zeits. fiir Nahr. u. Genuss., 1S98, pp. 42 and 44. 



4o8 



FOOD INSPECTION /IND ANALYSIS. 



crystallization; the shorter forms are rarely met with. Sometimes various 
forms are found side by side in the same crystallization. 

Phytosterol crystals, from a second or third recrj'stallization, some- 
times grow together in bunches resembling at fitst glance to the naked 
eye the cholesterol masses. They never do this in the first crystallization, 
whereas in the case of cholesterol the growing together in masses is very 
characteristic of the first crystallization. 












r 







Fig. 95. — Phytosterol Crystals, (.\fter Bomer.) 

Thus for purposes of distinguishing between the two the product 
of the first crystallization is best observed. 

Crystals ^} Mixed Cholesterol and Phytosterol. — In mixtures of the 
two they do not cr)'stallize separately, but when in nearly equal propor- 
tion, or with phytosterol predominating, the crystals much resemble 
phytosterol. Even when cholesterol predominates to the extent of 20 
parts to I of phytosterol, the mode of crystallization leans most toward 
that of phytosterol, though the needles are of different shape. Such a 
mixture, for instance, does not form in a film like cholesterol, but, like 
phytosterol, comes out in needle-like bunches. The needles, however, 
are more often like those shown in Fig. 97 when viewed under the micro- 




N 



hhi 




Fig. 97. — Characteristic Forms of Crystallization of Mixed Cholesterol and Phytosterol 

(After Bbmer.) 

scope, showing needles for the most part squarely cut off at the ends, 
and sometimes placed end to end, and of var}'ing diameter, giving the 
appearance of a spy-glass. When cliolesterol predominates over phy- 
tosterol 50 to I, the plates resemble those of cholesterol. 



EDIBLE OILS /IND FATS. 409 

Paraffin, sometimes present as an adulterant of fats, is best deter- 
mined as follows:* Boil 2 grams of the fat with 10 cc. of 95% alcohol 
and 2 cc. of I :i sodium hydroxide solution, connect the flask with a reflux 
condenser, and heat for an hour on the water-bath, or until saponification 
is complete. Remove the condenser, and allow the flask to remain on 
the bath till the alcohol is evaporated off and a dn,' residue is left. Treat 
the residue with about 40 cc. of water and heat on the bath, with frequent 
shaking, till everything soluble is in solution. Wash into a separatory 
funnel, cool, and extract with four successive portions of petroleum ether, 
which are collected in a tared flask or capsule. Remove the petroleum 
ether by evaporation and dry in the oven to constant weight. 

It should be noted that any phytosterol or cholesterol present in the 
fat would come down with the parafifin, but the amount would be so insig- 
nificant that with added paraftin actually present, it may be disregarded. 
The character of the final residue should, however, be confirmed by 
determining its melting-point and specific gravity, and by subjecting 
it to examination in the butyro-refractometer. The melting-point of 
paraffin is about 54.5° C; its specific gravity at 15.5° is from 0.868 to 
0.915, and on the butyro-refractometer the reading at 65° C. is from 
II to 14.5. 

MICROSCOPICAL EXAMINATION OF OILS AND FATS. 

Excepting in the case of solid fats, the use of the microscope has 
hitherto been comparatively restricted. In the examination of lard and 
butter for adulterants, the use of the microscope is often of great value, 
and will be described more fully under these special fats. In general 
the best fat crystals are obtained by slow crystallization at room tempera- 
ture from an ether solution, or from a mixture of ether and alcohol. The 
first crj'stals formed may often with advantage be filtered out, and washed 
with the alcohol and ether mixture on the filter, dissolved finally in ether, 
and the latter allowed to evaporate spontaneously. The cr}'stals are 
then examined in a medium of ether. 

If it be desired to separate the liquid oleins from an oil, so that crystals 
of the solid fats are left for examination. Gladding f recommends dis- 
solving the fat in a mixture of two volumes of absolute alcohol and one 
volume of ether in a test-tube, which is stoppered with cotton and set 
for half an hour in ice water, during which time the more solid stearin 

* U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 46. 
f Jour. Am. Chem. Soc, 1896, iS, p. iSg. 



4IO 



FOOD INSPECTION AND ANALYSIS. 






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EDIBLE OILS AND FATS. 



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FOOD INSPECTION /IND ANALYSIS. 



and palmitin will have crystallized out. This portion is then separated 
from the mother liquor by fiUration through an alcohol- wet filter- paper, 
and the crystals finally treated as in the preceding section, being examined 
in a medium of olive or cottonseed oil. 



OLIVE OIL. 

Source. — Olive oil is derived from the fruit of the cultivated thorn- 
less olive tree, Olea Europaa saliva* of which there are a great many 
varieties, originally grown in Asia Minor, Greece, Palestine, and southern 
Europe, and now cultivated extensively in California, Peru, and Mexico, 
as well as in Australia. Most of the olive oil of commerce, especially 
of the choicest varieties, is supplied by southern France, Spain, and Italy. 
The tree is an evergreen of slow growth and great longevity. 

The ripe olive fruit is purple or purplish black in color; it is round or 
oval in shape, and from 2.5 to 4 cm. in diameter. The oil is contained in 
the parenchyma cells of the fruit suspended in a watery fluid. A thick 
skin incloses the fruit, and within is a kernel, which itself contains oil. 
The fruit contains from 40 to 60 per cent of oil. According to Brannt,t 
the average composition of the olive is as follows: 





Flesh, 
Per Cent. 


Stone, 
Per Cent. 


Seed, 
Per Cent. 


Oil 


56-4 
16.70 

no 
2.68 
24.22 


5-75 
85.89 

2.50 
4.16 
4-20 

100.00 




Organic substances 


79-38 

2 16 


Nitrogen therein 


Ash 




Water 










100.00 


100.00 



Preparation. — The finest virgin oil is produced from hand-picked, 
peeled olives, from which the kernels or pits have been removed. A 
somewhat inferior grade of oil is produced from the whole olive including 
the pit, while a distinctly low grade oil is obtained from the stones, or 
kernels, which are ground into a coarse meal and subjected to pressure, or 
to the action of such solvents as carbon bisulphide. 

In the process of manufacture the fruit, after first being dried, is 
reduced to a pulp in a stone or iron mill, and the pulpy mass, contained 
in baskets or bags, is subjected to pressure in an iron press. The very 
highest grade of virgin oil is that which runs out from the pulp with little 

* As distinguished from the wild thorny species, Europaa sylvestris. 
t Animal and Vegetable Fats and Oils. 



EDIBLE OILS AND FATS. 413 

or no pressure. After the first pressing, the pomace is ground, treated 
with water, and again subjected to pressure. Several pressings in this 
manner may be carried out, each yielding an oil inferior to that preced- 
ing, the lowest grades being used for lubricants and in the manufacture 
of soap. 

Nature and Composition. — The better grades of olive oil, suitable for 
table and medicinal purposes, possess a pleasant, bland taste, and a 
distinctive and agreeable odor, unmistakable in character for that of any 
other oil. The finest virgin oil is pale green in color, due to the presence 
of chlorophyll, which is closely associated with the oil globules in the 
cellular tissue of the fruit. Some varieties of olive oil are nearly color- 
less, while others are a deep golden yellow. 
TTtir JC] . Olive oil contains 28% of solid glycerides, chiefly palmitin and a very 
small amount of arachin, and 72% of liquid glycerides, mainly olein with 
a little linolein. Stearin is practically absent. 

Lewkowitch* states that olive oil difiFers from most vegetable oils in 
containing cholesterol but not phytosterol. 

Gill and Tufts f show, as a result of numerous experiments, that olive 
oil is not thus exceptional, but that the unsaponifiable alcohol is phytos- 
terol and not cholesterol. 

Olive oil is very soluble in chloroform, benzol, and carbon bisulphide, 
but is sparingly soluble in alcohol. Five parts of ether will dissolve 
3 parts of the oil. 

Adulterants. — As a rule the low grade olive oils are most subject 
to aduheration, by reason of the fact that it hardly pays to destroy or 
even modify the fine quality and delicacy possessed by a first class oil, 
which would inevitably be the result if even a small amount of foreign oil 
were added. Furthermore, if olive oil be slightly rancid or for any reason 
lacking in flavor, the admixture of a bland oil tends rather to minimize 
the fact. 

The most common adulterant of olive oil in this country is naturally 
cottonseed oil, which is often substituted wholly for it. In Europe 
peanut oil is sometimes used both as an admixture and even as a substi- 
tute, since it possesses in itself a rather pleasant flavor, rendering it 
especially adapted for use as an adulterant. Other cheap oils used for 
this purpose are com, mustard, poppyseed, rape, sesame, and sunflower 



* Chem. Anal, of Oils, Fats, and Waxes, 2d ed., p. 452. 
t Jour. Am. Chem. Soc, XXV, 1903, p. 498. 



414 



FOOD INSPECTION AND ANALYSIS. 



oil. The writer has also found in samples of alleged olive oil sold in 
Massachusetts cocoanut oil * and even iish oil. 

Pure Olive Oil of the U. S. Pharmacopceia. — The requirements of the 
Pharmacopoeia are as follows: 
\ Specific gravity, 0.915 to 0.918 at 15° C. (59° F.). 

When cooled to about 10° C. (50° F.), the oil should become some- 
what cloudy from the separation of crystalline particles, and at 0° C. 
(32° F.) it should form a whitish, granular mass. 

If 10 cc. of the oil be shaken frequently, during two hours, with a 
freshly prepared solution of i gram of mercury in 3 cc. of nitric acid, 
a perfectly solid mass of pale straw color should be obtained. 

If 6 grams of the oil be thoroughly shaken in a test-tube for about 
two minutes with a mixture of 1.5 grams of nitric acid and 0.5 gram of 
water, then heated in a bath of boiling water for not more than fifteen 
minutes, the oil should retain a yellow color, not becoming orange or 
reddish brown, and, after standing at the ordinary temperature for about 
twelve hours, it should form a perfectly solid, light yellow mass (absence 
of appreciable quantities of cottonseed oil, and most other seed oils). 

Olive oil should not show the cottonseed oil reaction with the Bechi 
test, p. 418, nor the sesame oil reaction with the Badouin test, p. 420. 

Reaction with Strong Acid. — Pure olive oil, when shaken or stirred 
with an equal \olume of concentrated nitric or sulphuric acid, turns from 
a pale to a dark-green color in a few minutes. If, under this treatment, 
a reddish to an orange, or brown coloration is produced, the presence 
of a foreign vegetable oil (usually a seed oil) is to be suspected. 

Bach gives the following table showing the action of strong nitric acid 
on various oils: 



Kind of Oil. 


After Agitation 
with Nitric Acid. 


After Heating for 
Five Minutes. 


Consistency after 

Standing Twelve to 

Eighteen Hours. 


Olive 


Pale green 
' ' rose 

White 
Dirty white 

Yellowish brown 
Pale rose 


Orange-yellow 
Brownish yellow 
Orange-yellow 
Brownish yellow 
Reddish yellow 
Reddish brown 
Golden yellow 


Solid 




(< 




< I 




Liquid 




Buttery 






*i 







* A sample of alleged olive oil purchased in a Massachusetts drug store and found to 
be adulterated with cocoanut oil, had the following constants; 

Specific gravity 0.911 

Reichert-Meissl number 2.90 

Iodine number 74-5 

Butyro-refractometer at 26° 56.5 



EDIBLE OILS AND FATS. 



415 



The Zeiss Butyro-refractometer furnishes one of the most useful 
and easily applied preliminary means of judging the purity of the sample. 
If the reading is beyond the limits of pure olive oil, it at once indicates 
adulteration and often points to the particular adulterant. On the other 
hand, it is not always safe to assume the oil to be pure if the reading is 
correct, since, mixtures of higher and lower refracting foreign oils may 
be so skillfully prepared as to read well within the limits of the pure oil 
on the refractometer scale. The refractometer reading of pure cottonseed 
oil is almost five degrees higher than that of pure olive. 



READINGS ON ZEISS REFRACTOMETER OF OLIVE AND COTTONSEED 




OILS.* 






Scale Reading. 




Scale Reading. 


Temperature 




Temperature 
(Centigrade). 




(Centigrade). 












Olive Oil. 


Cottonseed Oil. 




Olive Oil. 


Cottonseed OiL 


35-° 


57-0 


61. S 


25-5 


62.4 


67-5 


34-5 


57-2 


62.1 


25.0 


63.0 


67.9 


34-0 


57-4 


62.3 


24-5 


63-3 


68.2 


33-5 


57-7 


62.5 


24.0 


63.6 


68.5 


33-° 


s8.o 


62.8 


23-5 


63-9 


68.8 


32-5 


58.3 


63.0 


23.0 


64.2 


69.1 


32.0 


58.5 


63.2 


22.5 


64-5 


69.4 


31-5 


59-° 


63.6 


22.0 


64.8 


69.7 


31-0 


59-2 


64.0 


21-5 


65.1 


70.0 


30-5 


59-4 


64.2 


21.0 


65.4 


70-3 


30.0 


59-9 


64.5 


20.5 


65.7 


70.6 


29-5 


60.1 


64.9 


20.0 


66.0 


70.9 


29.0 


60.3 


65.1 


19-5 


66.3 


71.2 


28.5 


60.6 


65-3 


19.0 


66.6 


71-5 


28.0 


60.9 


65.7 


18.5 


66.9 


71.8 


27.5 


61. 1 


66.0 


18.0 


67.2 


72.1 


27.0 


61.5 


66.5 


17-5 


67-5 


72.4 


26.5 


62.0 


67.0 


17.0 


67.8 


72.7 


26.0 


62.2 


67-3 


I6.S 


68.1 


73-0 



The Elaidin Test, in the case of pure olive oil, is very distinctive, since 
it yields by far the hardest elaidin of all the common oils, and solidifies 
the most quickly. 

Archbutt f shows the effect on this test of the mi.xture with olive oil 
of various proportions of rape and cottonseed oil, as follows: 



Kind of Oil. 



Minutes Required for Solid- 
ification at 25° C. 



Consistency. 



Olive oil 



-1- 10% rape oil 

+ 20% " 

+ 10% cottonseed oil. 

+ 20% 



230 

320 
From 9 to 1 1 4 hours 

" 9" Hi " 
More than iit " 



Hard but penetrable 
Buttery 

Very soft. 



' Ann. Rep. Mass. State Bd. of Health, 1899, p. 647. t Jour. Soc. Chem. Ind., 1897, p. 447. 



41 6 FOOD INSPECTION /IND /IN A LYSIS. 

Cottonseed Oil as an adulterant is best detected by means of the Hal- 
phen or Bechi tests. Its presence in notable quantities increases the 
specific gravity, refractometer reading, and iodine number verj' materially. 
Its high Maumene figure is also distinctive. 

Peanut Oil, when present to a considerable extent, betrays its presence 
by its peculiar bean-like flavor. Most of the constants of peanut oil 
lie within the limits of olive oil, with the exception of the refractometer 
reading, which is somewhat higher. A considerable admixture of peanut 
oil raises the refractometer reading perceptibly over that of pure olive. 
Its presence is best detected, however, by tests for arachidic acid (p. 424), 
taking care not to neglect the fact that pure olive oils of certain varieties ^ • 
have been known to respond to these tests. ^j^v\_'.c<u':tt'-I-4' ^ 

Sesame Oil differs more particularly from olive in its higher specific 
gravity and iodine and Maumene numbers, and is readily detected by 
distinctive color tests (p. 420). 

Rape Oil is characterized by a much lower saponification value and 
higher iodine number than olive. 

Com Oil differs materially from olive in its exceedingly high iodine 
number and refractometer reading. Its specific gravity and saponifica- 
tion numbers are also higher. 

Lard Oil, when present in considerable quantity, is often rendered 
apparent by its characteristic odor on warming. Its low refractometer 
reading and iodine number are also distinctive. 

Poppyseed Oil differs most widely from olive oil in its refractometric 
reading, its high dispersion, and its Maumene number, which in tlie case 
of poppyseed is 87° and of olive about 42°. 

Cocoanut Oil in mixture with olive perceptibly raises the solidifying- 
point. When more than 12% of cocoanut oil is present, the sample will 
become solid when placed in ice water. 

Fish Oils, when present, are rendered apparent by reason of their 
strong taste and smell, and by their very high iodine number. Boiling 
the sample with sodium hydroxide develops a peculiar reddish colora- 
tion, when fish oils are present. 

Routine Examination of Olive Oil for Adulterants. — First note the 
smell and taste of the sample, and then take the refractometric reading. 
An abnormally high refraction indicates adulteration. Then lest with 
strong nitric acid (p. 414). If the refraction is normal, and the color 
resulting from the acid reaction a pale green, the presumption is that 
the oil is pure. Test first for cottonseed oil by the Halphen reaction, 



EDIBLE OILS AND F/ITS. 417 

and then in succession try the various color reactions for sesame and rape 
oils. If all these are absent, and, by abnormal constants, or by color 
with nitric acid, there is reason to believe the oil is adulterated, determine 
carefully such of the constants as are most indicative, by their wide 
variation from olive, of poppyseed, mustard, and corn oils. 

If all these oils are presumably absent, and either a high refractom- 
eter reading or a color reaction with nitric acid still indicates adultera- 
tion, peanut oil is more than likely to be present, and should be tested for 
either by Renard's or Bellier's method. 

The edible oils and adulterants are arranged in order of their relative 
price about as follows: 

Olive oil. 

Lard oil. 

Peanut oil. 

Sesame oil. 

Poppyseed oil. 

Rape oil. 

Corn oil. 

Cottonseed oil. 

COTTONSEED OIL. 

Source and Preparation. — This oil, largely used as a table oil and as 
an adulterant of olive oil, is derived from seeds of the various species 
of the cotton plant, Gossipium, of which the most common are G. herba- 
ceiim, native to Asia, but cultivated extensively in southern Europe and 
in the United States, G. religiosum, in China and the East Indies, and- G. 
barbadense, in the West Indies. 

The seeds are in reality a by-product in cotton manufacture. In 
shape they are irregularly oval, measuring from 5 to 8 mm. greatest diam- 
eter. The seed skin or pod is covered with the tiber of the cotton. 

The seeds are first cleaned and separated from dirt by sifting machines, 
and from the fiber by specially constructed gins, after which they are 
cut into small pieces, freed from their hulls, crushed between rollers, and 
afterward submitted to hydraulic pressure in bags to express the oil, 
which is clarified by filtration or refined. The refining consists in wash- 
ing the crude oil with sodium hydroxide solution, whereby the impuri- 
ties are dissolved and thus removed. 

Nature and Composition of Seeds and Oil. — The seeds of the cotton 
plant are rich in oil, containing from 10 to 29 per cent, according to the 



4i8 



FOOD INSPECTION AND ANALYSIS. 



variety. Four samples of American cottonseed were found to be com- 
posed as follows, according to Brannt:* 



Constituents. 



South 


Georgia 


Georgia 


Carolina. 


I. 


II. 


9-S 


10. 1 


9.8 


20. 1 


16.2 


17. 1 


17.8 


17-4 


17.2 


2-3 


2.9 


3-2 


.8 


-9 


-7 


26.2 


27.4 


26.1 


17.6 


19.2 


19.8 


S-7 


5-9 


6.1 


100. 


100. 


100. 



Georgia 
III. 



Water 

Cottonseed oil 

Nitrogenous compounds 

Ammonia-making compounds 

Gum, sugar, and soluble starch 

Cellulose, starch, and resin 

Ligneous tissue 

Ash (phosphate of lime, silica, alumina, 
iron, magnesia, potash, soda, etc.) 



8.2 
19.6 
18. 1 

3-7 

-9 

20.7 

22.4 

6.4 



Refined cottonseed oil is a pale-yellow oil of thick consistency, possess- 
ing a bland though pleasant taste and odor. It consists of the glycer- 
ides of oleic, stearic, palmitic, and linoleic acids, and evidently also a small 
content of hydroxyacids, though this has not been investigated as yet. 

On cooling the oil to a temperature below 12° C. particles of solid 
fat will separate. At about 0° to - 5° C. the oil solidifies. When the 
oil is brought in contact with concentrated sulphuric acid, a dark, red- 
dish-brown color is instantly produced. 

Cottonseed Stearin. — This product, used as an adulterant of lard 
as well as a substitute therefor, is obtained by submitting the oil to a low 
temperature, and subjecting the solid portion that separates out to pres- 
sure. It is a light-yellow fat, resembling butter in consistency. 

Cottonseed oil from its cheapness is rarely adulterated by the admix- 
ture of foreign oil, but inferior grades are often sold for the best. 

Bechi's Silver Nitrate Test. — Hehner's Modification. — Two grams of 
silver nitrate are dissolved in 200 cc. of 95% alcohol free from aldehyde, 
40 cc. of ether are added, and the reagent made very slightly acid with 
nitric acid. 

In applying the test, a small quantity of the melted fat or oil is mixed 
in a test-tube with half its volume of the above reagent,, and the tube is 
immersed in boiling water for fifteen minutes. With proper precautions 
the presence of cottonseed oil is indicated by a more or less strong reduc- 
tion of the silver, while an oil or fat free from cottonseed oil causes 
no appreciable reduction. 

Certain oils free from cottonseed that have become rancid or decom- 
posed, as well as fats that have been subjected to a high temperature, 

* Vegetable Fats and Oils, p. 223. 



EDIBLE OILS AND FATS. 419 

sometimes show a slight reduction with Bechi's test. In cases of doubt 
it is well to apply the test on the fatty acids as follows: 

Milliau^s Modification oj Beckys Test.* — Heat 20 grams of the 
sample with 30 cc. of alcoholic potash solution (20% sodium hydroxide 
in 70% alcohol), shaking at intervals till saponification is complete. 
Continue the heating for some minutes afterward until the alcohol is 
driven oflf, and dissolve the soap in 250 cc. of hot water. Add a slight 
excess of 10% sulphuric acid, and wash the separated fatty acids three 
times by decantation with water. Then proceed with a portion of the 
fatty acids as in Bechi's test. 

Halphen's Test. — This is a much more delicate test for cottonseed 
oil than either of the preceding, as little as 2% of cottonseed oil being 
rendered apparent in olive oil. A mixture is made of equal volumes 
of amyl alcohol and carbon bisulphide in which 1% of sulphur has been 
dissolved. From 3 to 5 cc. of melted fat are mixed with an equal volume 
of the above reagent in a test-tube, loosely stoppered with cotton, and 
heated in a bath of boiling saturated brine for fifteen minutes. If 
cottonseed oil is present, a deep-red or orange color is produced. In 
its absence little or no color is developed. 

Previous heating of the oil diminishes the delicacy of the Halphen 
test, and Holde and Pelgry f state that if cottonseed oil has been heated 
at 250° for ten minutes, it will fail to respond to the test. 

SESAME OIL. 

Sesame, otherwise known as benne, oil is pressed from the seeds of 
Sesamum indicum and Sesamum orientate, plants which are native to 
southern Asia, but now extensively cultivated in nearly all tropical coun- 
tries. The larger portion of commercial sesame oil is manufactured in 
England, France, Germany, and Austria. 

The seeds are yellow to dark brown, and in some cases black, inclined 
to the oval in form, the average longest diameter being about 4 mm. 

The seeds are commonly subjected to cold pressure once, and after- 
wards twice pressed when warm, thus yielding three grades of oil. From 
47 to 60 per cent of oil is contained in the seeds. 

According to Brannt | the composition of sesame seeds is as follows : 



* Moniteur Scientifique, 1888, p. 366. 

t Jour. Soc. Chera. Ind., 1899, iS, p. 711. 

X Vegetable Fats and Oils, p. 251. 



420 



FOOD INSPECTION /IND ANALYSIS. 





Sesamum 
Orientale. 


Sesamum 
Indicum. 


Oil. 


55-63 

30.95 

21.42 

3-39 

7.52 

3-90 


50.84 

35-25 

22.30 

3-56 
6.85 
7.06 


Organic substances 

Protein therein 

Nitrogen therein 

Ash 


Water 




100.00 


100.00 



Sesame oil consists of the glycerides of oleic, stearic, palmitic, and 
myristic acids. It is golden yellow in color, free from odor, and pos- 
sesses a delicate and characteristic flavor, on account of which the 
highest grades are by some considered equal to olive oil as a condiment. 
It is accordingly sold to some extent as an edible oil. It was formerly 
used as an adulterant of olive oil, but has of late years been largely dis- 
placed by cheaper oils for purposes of adulteration. When cooled to 
— 3°C., sesame oil congeals to a yellowish- white mass. Concentrated 
sulphuric acid converts it into a brownish-red jelly. 

Adulterants to be looked for in sesame oil are cottonseed, popp}'- 
seed, corn, and rape oils. 

Tocher's Test.* — One gram of pyrogallic acid is dissolved in 15 cc. 
of concentrated hydrochloric acid and mi.xed with 15 cc. of the sample 
in a separatory funnel. After standing for a minute, the aqueous solu- 
tion is withdrawn and boiled. If sesame oil is present, the solution 
shows a red coloration by transmitted, and blue by reflected, light 

Badouin's Test.f — Dissolve o.i gram of cane sugar in 10 cc. of hydro- 
chloric acid (specific gravity 1.20) in a test-tube, and shake thoroughly 
with 20 grams of the oil to be tested for one minute. Then allow the 
mixture to stand. The aqueous solution quickly separates from the oil, 
and in the presence of 1% or more of sesame oil will be colored deep red. 

Certain pure Tunisian and Algerian olive oils have been found to 
cause a slight coloration with this test, but of a different shade from sesame. 
Moreover, if the test is applied to the fatty acids of the oil, no coloration 
in the case of olive is produced, while with sesame the color is the same as 
with the oil. 

Villivecchia and Fabris Test.t — This test was suggested on account 
of the fact that the color reaction in the Badouin test was attributed to 



* Chem. Zeit. Rep., 1891 (5), 15-33. 
t Zeits. angew. Chem., 1892, p. 509. 
X Jour. Soc. Chem. Ind., 1S94, pp. 13-69. 



EDIBLE OILS AND FATS. 



421 



the agency of the levulose produced by the inversion of the sugar by 
hydrochloric acid. As furfurol is the chief product of the reaction between 
levulose and hydrochloric acid, it was substituted as follows: Dissolve 2 
grams of furfurol in 100 cc. of 95% alcohol, and shake o.i cc. of this solu- 
tion in a test-tube with 10 cc. of the oil to be tested and 10 cc. of hydro- 
chloric acid (specific gravity 1.20) for half a minute. The aqueous 
layer, on settling out, will be colored deep red, if sesame is present. 

Or 0.1 cc. of the alcohol furfurol solution is mixed with 10 cc. of 
oil and i cc. of hydrochloric acid in a separatory funnel, shaken well, 
and the separation aided by the addition of chloroform, which causes 
the aqueous layer, showing color with sesame oil, to float. 

Since furfurol produces with hydrochloric acid alone a violet colora- 
tion, it is necessary to use it in dilute solution as above. 



RAPE OIL. 

Rape or colza oil is expressed from the seeds of the Brassica or rape- 
plant, of which there are three principal varities, Brassica napus, B. coni- 
pestris, and B. rapa, one or another of which are cultivated in nearly 
every country of Europe, excepting Greece. Large amounts are also 
grown in India and China. The seeds are small, round grains, from 
2 to 2.5 mm. in diameter, yielding from 30 to 45 per cent of oil. The 
seeds, according to Brannt,* have the following average composition: 





Fresh Seeds. 


Old Seeds. 


Oil 


36 -So 

49-30 

2.50 
4.80 
g.io 


38-5° 
53-25 

3-II 
3-90 

4-35 


Organic substances 

Nitrogen therein 

Ash 

Water. .. 




100.00 


roo.oo 



In the process of preparation the seeds are first crushed, and the oil 
removed by pressing or extraction. The crude oil is of a brownish- 
yellow color, and when fresh is almost free from taste and smell, so that 
it serves, when cold pressed, as an edible oil, or an adulterant of such 
oils. It develops a disagreeable and peculiar taste and odor on long 
standing, due to the presence of certain albuminous and mucilaginous 
substances which it contains. These may be removed by refining, usually 
by treatment with sulphuric acid, but the refined oil has an unpleasant 
taste and odor. 

* Vegetable Fats and Oils, p. 240. 



422 



FOOD INSPECTION AND ANALYSIS. 



The principal components of rape oil are the glycerides of stearic, 
oleic, erucic, and rapic acids. The chief adulterants are cottonseed 
and poppyseed oils. 

Palas Test for Rapeseed Oil.* — Mix in the cold 30 cc. of a 1% solu- 
tion of fuchsin, 20 cc. of sodium bisulphite (specific gravity 1.31), 200 cc. 
of water, and 5 cc. sulphuric acid. If the sample of oil to be tested be 
shaken with the reagent, a rose-red coloration is obtained in the presence 
of rape oil, said to be delicate to the extent of detecting 2% of the oil in 
mixtures. 



CORN OR MAIZE OIL. 



Corn oil is derived from the seed of the American grain Zea mays, or 
Indian corn, the constitution of the yellow and white varieties of which 
is, according to Andes, f as follows: 





Yellow Corn, 
Per Cent. 


White Com. 
Per Cent. 


Organic matter 

Starch 


82.93 

61.95 
10.71 

1-32 
9.50 
6.25 


80.76 

62.23 
9.62 
1.04 
10.60 
7.60 

100.00 


Albuminoids 

Ash 


Water 


Oil 




100.00 



Nearly all the oil is contained in the germ of the seed, the oil con- 
stituting in fact over 20% of the germ. Corn oil consists chiefly of the 
glycerides of palmitic and oleic acids. There is some doubt as to the 
presence of stearin. It is golden yellow in color, and possesses a pleasant 
odor and taste, resembling in ilavor freshly ground grain. 

It is prepared by subjecting to hydraulic pressure the germ separated 
in the manufacture of starch and of glucose, the germs yielding about 
15% of pure oil. While most of the oil of commerce is a by-product 
from starch and glucose factories, a small amount is recovered from the 
residue of fermentation vats in the manufacture of alcohol. Com oil is 
coming to be used more and more as an adulterant of olive oil, and, 
according to Lewkowitsch, of lard. 

It is claimed by Hopkins,t by Hoppe-Seyler, and others, that corn oil, 

* Analyst, XXII, p. 45. 

f Vegetable Fats and Oils, p. 131. 

% Jour. Am. Chcm. Soc, 1898, 20, p. 948. 



EDIBLE OILS AND FATS. 



423 



unlike most vegetable oils, contains cholesterol. Olive oil was long 
supposed to be unique as a vegetable oil in containing this substance. 
Hoplcins, on the assumption that cholesterol occurs in com oil, sug- 
gested that a test for corn oil as an adulterant of certain vegetable oils 
lay in the identification of cholesterol. 

Gill and Tufts * claim that, while the alcohol of corn oil is not phytos- 
terol, neither is it cholesterol, but a third substance, known as sitosterol, f 
occurring in wheat and rye. 

There are no color reactions identifying corn oil as such. Its pres- 
ence in other oils is indicated only by its influence on the various con- 
stants, the iodine number and refractometric reading especially being 
much higher than those of other edible oils. 

PEANUT OIL. 

Peanut or arachis oil is obtained from the seeds of the Arachis hypo- 
gma (peanut, ground nut, or earth nut) cultivated in most tropical coun- 
tries, notably in South America, China, India, and Japan. The plant 
is a creeping herb, developing its blossoms in the axes of the leaves. The 
fruit buds grow down into the earth, where the fruit is ripened, forming 
the well-known peanuts of commerce, the composition of which, accord- 
ing to Brannt, is as follows: 





Per Cent. 


Per Cent. 


Oil 


37-48 
52.86 

27.25 

2-43 

7-37 


to 41.63 
" 53-" 

= 7-85 

" 2 . 50 
" 2.75 


Organic substances 


Ash 


Water 




100.00 


100.00 



Peanut oil is composed chiefly of the glycerides of oleic, palmitic, 
hypogasic, and arachidic acids. The oil is extracted by pressure, the 
first cold-drawn oil being practically colorless, and possessing a pleasant 
taste suggestive of kidney beans. It is especially adapted for use ai 
a salad or table oil. A second pressure of the moistened residue from 
the first yields an inferior oil, yellowish in color, also somewhat used 
for edible purposes, and sometimes commercially called "butterine oil." 

* Jour. Am. Chem. Sec, XXV, 1903. 

t Burian, Monatsh. Chem., 18, 1897, p. 551. 



424 FOOD INSPECTION AND ANALYSIS. 

Adulterants of peanut oil are cottonseed, poppyseed, rape, and 
sesame oils. Very little pure peanut oil is found in commerce in the 
United States. It is to be looked for as an adulterant of French and 
Italian olive oils. 

Characteristic Tests. — Peanut oil, when pure or nearly pure, may 
Qs a rule be readily identified from other oils. When present in large 
admixture in other oils it is not difficult to detect, but when only a small 
amount is present, in olive oil for instance, its detection becomes a more 
troublesome matter. 

This difficulty arises from the fact that the constants of peanut oil 
are nearly the same as those of olive, with the single exception of the 
refractometric reading. Furthermore, there is no readily applied color 
test identifying peanut oil. 

All the other common adulterants of olive oil, as cottonseed, sesame, 
corn, poppyseed, and rape oils, are readily identified, when present in 
small amounts, either by special color tests, or by reason of the fact that 
certain of their constants differ very widely from those of olive oil. Much 
more care and precaution are necessary in dealing with small admi.xtures 
of peanut oil than with almost any other adulterant. 

The Renard Test* has long been in use for detecting and estimating 
peanut oil in mixtures, but cannot be regarded as entirely satisfactor}-, 
since it has been found to give the reaction for arachidic acid in cases of 
certain varieties of pure olive oil, as well as of cottonseed and sesame /■' 
oils, known to be free from peanut oil. Under these conditions it can; -'■ 
hardly be regarded as infallible, and by many is deemed useful chiefly ' - 
as a confirmatory negative test in proving the absence of peanut oil frorn) '_ 
a doubtful sample. 

Tolmant claims to be able to obtain positive results by carrying out 
the Renard method as follows: 

Five grams of the oil are saponified in a 250-cc. Erlenmeyer flask with 
50 cc. of alcoholic potassium hydroxide (40 grams potassium hydroxide 
in I liter of 95% redistilled alcohol). Neutralize with dilute acetic acid, 
using phenolphthalein as an indicator, and wash into a 500-cc. flask 
containing a boiling mixture of 200 cc. water and 60 cc. 10% solution 
of lead acetate. 

Boil for a minute and cool the contents of the flask by immersing 
in cold, or, preferably, ice water, whirling the flask occasionally so that 

* Comp. Rend., 1871, 73, p. 1330. 

t U. S. Dept. of Agric, Bur. of Chem., Bui. 65; also Bui. 77. 



EDIBLE OILS AND l-ATS. 425 

the soap when cold adheres to the sides of the flask. The water and 
excess of lead acetate can then be poured out, leaving the soap in the 
flask. Wash by shaking and decantation, first with cold water and 
then with 90% alcohol. .Add 200 cc. of ether, cork the flask, and allow 
to stand with occasional shaking till the soap is disintegrated, after which 
boil on a water-bath under a reflux condenser for five minutes. Cool 
the soap solution down to a temperature between 15° and 17°, and allow 
it to stand for about tweh'e hours. 

Filter and wash the precipitate with ether, after which the soap in 
the filter is washed back into the original flask with a stream of hot water 
acidulated with hydrochloric acid. 

Add an excess of hydrochloric acid and enough hot water to make 
a volume of from 300 to 400 cc, and cool in ice water till the fatty acids 
have hardened and separated from the lead chloride. Then fiher, wash 
the precipitate with water, and, after draining dry, pour slowly through the 
filter 25 cc. of boiling 95% alcohol. The crj'stals of arachidic acid separate 
out as the solution cools. To further purify, filter and wash the pre- 
cipitate into a flask with a stream of alcohol, measuring the volume used, 
which should be about 20 cc. Cork the flask, shake, and again filter, 
and wash with 70% alcohol. Finally dissolve off the precipitate with 
boiling absolute alcohol, evaporate to dryness in a tared dish, dry and 
weigh. To the weight add 0.0025 gram for each 10 cc. of 95% alcohol 
used in the crystallization and washing, if done at 15° C, and 0.0045 gram 
for each 10 cc. if done at 20°. 

The approximate amount of peanut oil is found by multiplying the 
weight of arachidic acid by 20. 

Arachidic acid crystals thus obtained should be examined micro- 
scopically, and the melting-point determined. For arachidic acid obtained 
in this manner the melting-point should lie between 71° and 72° C. 

Methods of J. Bellier.* — Qualitative Test. — Saponify i gram of the 
oil with 5 cc. of an alcoholic potash solution containing 85 grams po- 
tassium hydroxide per liter of strong alcohol, conducting the saponi- 
fication in a small Erlennieyer flask on the water-bath. After saponi- 
fication, boil for two minutes, neutralize with dilute acetic acid, using 
phcnolphthalcin as an indicator, and cool by setting the flask in water 
at a temperature of from 17° to 19°. After a short time, a precipitate 
nearly always comes down. Then add to the solution 50 cc. of 70% 
alcohol, containing 1% by volume of strong hA'drochloric acid (specific 

* Ann. Chim. Anal., 1899, 4, p. 49; Zeits. fur untersuch. Nahr., 1899, 2, p. 726. 



426 FOOD INSPECTION AND /IN A LYSIS. 

gravity 1.20). Cork the flask, shake vigorously, and again cool by setting 
the flask in the above cooling-bath. In the absence of a precipitate, the 
oil may be pronounced free from peanut. If 10% or more of peanut oil 
is present, a more or less characteristic precipitate forms, and often with 
less than 10% a cloudiness in the solution is perceptible after standing 
between 17° and 19° for half an hour. Pure olive oil remains perfectly 
clear as a rule. 

A few varieties of olive oil from Tunis especially high in solid fat 
acids, as wefl as cottonseed oil and sesame oil, give similar turbidity on 
the addition of the 70% alcohol. To distinguish between these oils 
and peanut oil, heat ihe mixture on the water-bath till complete solution 
takes place, and again cool to 17° to 19°. In the case of peanut oil the 
cloudiness or precipitate again occurs to the same extent as before, while 
in the other cases the solution should remain clear or nearly so. 

Quantitative Determination. — Saponify 5 grams of the oil with 25 cc. 
of the above alcoholic potash solution in a 250-cc. Erlenmeyer flask, 
neutraHze exactly with acetic acid, and cool quickly in water. After 
standing an hour, pour upon a 9-cc. fiUer and wash the precipitate with 
70% alcohol containing 18% by volume of hydrochloric acid, the tem^ 
perature of the solution being not less than 16° nor more than 20°. Con- 
tinue the washing till the wash water no longer shows turbidity when 
diluted with water. 

Dissolve the precipitate in 25 to 30 cc. of hot 95% alcohol, dilute with 
water until the alcohol is 70%, let stand in water at 20°, filter, wash with 
10% alcohol, dry at 100°, and weigh. 

Bellier states that he has recognized with certainty as small an admix- 
ture as 2% of peanut oil by this method. 

MUSTARD OIL. 

The fixed oil of mustard is a by-product expressed from the seeds 
of the black and white mustard {Sinapis nigra and S. alba) in the process 
of preparation of mustard flour as a spice. The seeds contain from 
25 to 35 per cent of oil. 

Mustard oil somewhat resembles rape in composition, containing 
glycerides of erucic, behenic, and probably rapic acid. 

Black mustard oil is brownish yellow in color, having a mild flavor, 
and an odor but slightly suggestive of mustard. White mustard oil is 
golden yellow, and has a somewhat sharp taste. 



EDIBLE OILS AND FATS. 



427 



Mustard oil is an alleged adulterant of edible oils, though by no means 
a common one. 



POPPYSEED OIL. 

This oil is obtained from the seeds of the opium poppy {Papaver 
somnijerum), native in the countries east of the Mediterranean, and cul- 
tivated extensively for opium and for oil in all parts of Europe, Asiatic 
Turkey, Persia, Egypt, India, and China. Most of the oil of conmierce 
comes from France and Germany. 

There are two chief varieties of poppy, the black (P. nigrum) and 
the white (P. album), the finest oil being produced from the white. The 
seeds are somewhat flattened in form and kidney-shaped, yielding from 
40 to 60 per cent of oil. According to Brannt the seeds have the follow- 
ing composition: 





White Poppy- 
seed. 


Black Poppy- 
seed. 


Oil 


55-62 
32. n 

16 89 

3-42 

8.85 


51 -,36 
35-14 

17-50 
4.00 

9-5° 


Organic substances 

Protein therein 

Ash 

Water 


100.00 


100.00 



The oil is obtained by crushing the seeds and applying pressure. 
The best grade of cold-drawn oil is pale yellow in color, possessing a 
pleasant taste when fresh, and being practically free from odor. Lower 
grades shade into deeper yellow and even reddish color, possessing a 
strong taste and odor. Poppyseed oil is much used in Europe as a table 
oil, and does not readily turn rancid. It is composed of the glycerides of 
stearic, palmitic, and linoleic acids. Poppyseed oil has been used to some 
extent as an adulterant of olive oil. It is itself not infrequently adulter- 
ated with sesame oil. 



SUNFLOWER OIL. 



Sunflower oil is derived from the seed kernels of the plant of the same 
name {Helianthus annuus), originally grown in Mexico, but now culti- 
vated most extensively on a commercial scale in southern Russia. 



428 



FOOD INSPECTION AND ANALYSIS. 



According to S. M. Babcock * the composition of sunflower seeds 
is as follows: 





Air-dry. 


Dried. 


Water . . . . . 


12.68 
3.00 
15.88 
29.21 
18.71 
20.52 


3-43 
1S.19 

33-45 
21-43 
23-50 


Ash 


Albuminoids (N X 6.25) 


Nitrogen-free extract 

Fat (ether extract) 


100.00 


100. o« 



The seeds arc long, black, and oval in shape, yielding from i8 to 28 
per cent of oil. The liquid fatty acids of sunflower oil consist for the 
most part of linoleic, but little oleic acid being found. 

The seeds are first shelled, then crushed, and finally submitted to 
pressure both cold and hot. 

Sunflower oil is pale yellow in color, has a mild, pleasant taste, and 
is nearly free from odor. The cold-drawn oil is the variety most used 
for edible and culinary purposes in Russia, and as an adulterant of olive 
oil. Its use as an adulterant is, however, limited, and the writer has no 
knowledge of its having been found in olive oils used in the United States. 



ROSIN OIL. 

Rosin oil is prepared by the distillation of common rosin, and is an 
alleged adulterant of olive oil. It may be detected when present by 
shaking i to 2 cc. of the sample with acetic anhydride while warming. 
Cool, remove the anhydride by a pipette, and add a drop of sulphuric 
acid (specific gravity 1.53). Rosin oil gives a fugitive-violet color.f 

Cholesterol also responds to this color reaction. 

Renard's Test for Rosin Oil. — Prepare a solution of stannic bromide 
by allowing dry bromine to fall drop by drop upon tin in a dry, cool flask, 
and dissolving the product in carbon bisulphide. 

Add a drop of this reagent to i cc. of the oil. In presence of rosin 
oil a violet color will be produced. 

Polarization Test for Rosin Oil.f — The oil is dissolved in definite 
proportion in petroleum ether, and polarized in a 200-mm. tube. Rosin 

* The Sunflower Plant, its Cultivation, Composition, and Uses. U. S. Dept. of Agric, 
Div. of Chem., Bui. 60, p. 18. 

t U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 32. 



EDIBLE OILS AND FATS. 



429 



oil polarizes from + 30 to + 40 on the cane sugar scale, while other oils 
have a reading between + 1 and — i. 



COCOANUT OIL. 

Cocoanut oil is the fat expressed from the kernels of the cocoanut 
or fruit of the cocoa palm (Cocos nucifcra), indigenous to the South Sea 
Islands and to the East-Indian archipelago, but grown in many tropical 
countries. 

It is sometimes known as "copra oil," from the copra or pulp, which 
contains from 60 to 70 per cent, of fat. According to Brannt, the com- 
position of the pulp is as follows: 





Indian Copra. 


African Copra. 


Oil 


68.75 

23-65 

9-16 

1-45 
6-15 


66.80 

25-25 

10.20 
I -50 
6-45 


Organic substances 


Albuminous substances 

Ash 


Water 




lOO-OO 


lOO-OO 



In the preparation of the oil the moist copra is separated from the 
shell, crushed in mortars and subjected to pressure, yielding a milky 
mass. This is then heated in boilers, and the oil which rises to the sur- 
face is removed by skimming. 

In some localities the pulp is first dried and then pressed. 

Cocoanut oil is usually white and possesses a mild taste and pleasant 
odor. The cold-drawn Malabar oil is of greenish color, and is used by 
the natives as an edible oil or substitute for butter. This variety is seldom 
found in commerce. 

Cocoanut oil contains, besides palmitin and olein, large proportions 
of myristin and laurin. Unlike the other vegetable oils, it contains also 
notable quantities of the glycerides of the volatile fatty acids caproic, 
capric, and caprylic, hence the high saponification value and Reichert 
number are the two most distinguishing constants. The oil is rarely 
adulterated. 

Cocoanut oil easily becomes rancid. According to Andes, crystals of 
cocoanut oil appear under the microscope as a thick network of long 
needles. 



430 FOOD INSPECTION AND ANALYSIS. 

COCOA (cacao) butter. 

This preparation is not, properly speaking, in itself an edible fat. It 
is a by-product in the manufacture of cocoa, being removed by pressure 
from the crushed and ground cocoa nibs. The fat in cocoa beans varies 
from 36 to 50 per cent. The expressed fat is yellowish white, of a tallow- 
like consistency, has a pleasant taste and an odor suggestive of chocolate. 
It keeps a long time without turning rancid. In composition it consists 
of the glycerides of stearic, palmitic, and lauric acids, with traces of the 
glycerides of arachidic and butyric acids. 

Its demand for pharmaceutical purposes is, however, sufficiently great 
to render the use of cocoa-butter as an aduUerant of food-fats extremely 
rare. It should be borne in mind as a possible adulterant in examining 
various oils. 

It is subject to adulteration with paraffin, tallow, and cottonseed 
stearin. 

TALLOW. 

The rendered fats of various animals, especially the cow and sheep, 
constitute what is generally known as tallow. The untreated fatty tis- 
sues are more properly known as suet, the tallow being the clear fat 
separated entirely by heat from the cellular material. 

Tallow consists almost entirely of olein, palmitin, and stearin. Mut- 
ton tallow is usually, but not always, harder than beef tallow. 

Excepting in the manufacture of material for oleomargarine; wherein 
the heart and caul fats of beef arc almost exclusively used, the fats from 
different parts of the animal are not, as a rule, separated. 

Fresh tallow has very little free fatty acid, but when it becomes rancid, 
the fat contains sometimes as high as 12% of free acid, reckoned as oleic. 

Tallow is of chief interest to the food analyst in connection with its 
use as an adulterant of lard. 

BUTTER. 

Nature and Composition. — Butter is the product obtained by the 
churning of cream or milk, whereby the fat particles are caused to adhere 
together into a compact mass, inclosing a certain portion of the casein, the 
excess of milk serum being subsequently largely removed by washing and 
mechanical working. 



EDIBLE OILS AND FATS. 



431 



Butter fat is of extremely complex composition, containing a larger 
variety of glycerides than any other fat. Besides olein, palmitin, and 
stearin, the usual glycerides of the insoluble or fixed fatty acids found 
in most fats, butter contains notable quantities of the glycerides of a 
number of the volatile fatty acids, chief among which are butyrin, caproin, 
caprin, and capr\'lin, to which are due its distinctive taste, and which 
by exposure to light and air readily become decomposed into their fatty 
acids — butyric, caproic, capric, and caprylic, respectively. This decom- 
position in butter causes, or, more properly speaking, accompanies, what 
is commonly known as "rancidity." 

The process of separation of butter fat into its component glycerides 
is a matter of extreme difficulty, and results obtained by different chemists 
vary widely. Separation has been attempted by fractional distillation, 
by methods depending on the difference in chemical affinity of the various 
acids, and on the difference in solubility of the various lower homo- 
logues in water at different temperatures.* 

According to Brown, the composition of butter fat is as follows: 



Acid. 


Percentage of 
Acid. 


Percentage of 
Triglycerides. 


Dio.wstearic 


I.OO 

32-5° 
1.83 

38.61 
9.89 

2-57 
0.32 
0.49 
2.09 

5-45 


1.04 

33-95 
1. 91 
40.51 
10.44 
2-73 
0.34 
0-53 
2.32 
6.23 


Oleic 


Stearic 


Palmitic 


Mvristic 


Laurie 


Capric 

Caprvlic 


Caproic 




Totals 


94-75 


100.00 





Upwards of 300 analyses of butter are summarized by Konig in the 
following table: 





Water, 
Per Cent. 


Fat, 
Per Cent. 


Casein, 
Per Cent. 


Milk, 
Per Cent. 


Sugar, 
Per Cent. 


Lactic Acid, 
Per Cent. 


Salts, 
Per Cent. 


Minimum 

Maximum 


4-15 
35-15 
13-59 


69.96 
86.15 
84-39 


0.19 
4.78 
0.74 


0.50 


0-45 
1. 16 


0.12 


0.02 

15-08 

0.66 





* Brown, .\ Contribution to the Chemistry of Butter Fat, Jour. Am. Chem. Soc, 21, 
1899, p. 807. 



432 FOOD INSPECTION AND /ANALYSIS. 



ANALYSES OF BUTTER. 

Preparation of the Sample. — (.4. O. A. C. Method.) * — If large quan- 
tities of butter are to be sampled, a butter-trier or sampler may be used. 
The portions thus drawn, about 500 grams, are to be perfectly melted 
in a closed vessel at as low a temperature as possible, and when melted, 
the whole is to be shaken violently for some minutes till the mass is homo- 
geneous, and sufficiently solidified to prevent the separation of the water 
and fat. A portion is then poured into the vessel from which it is to be 
weighed for analysis, and should nearly or quite fill it. This sample 
should be kept in a cold place till analyzed. 

Water. — About 2 grams of the sample are weighed in a flat-bottomed 
platinum dish such as is used for determining water in milk, and the dish 
and its contents kept in contact with the live stream of a water-bath till 
a constant weight is attained. 

Fat. — This may be determined cither directly or indirectly. Foi 
the direct determination, a weighed amount of the sample, from 2 to 3 
grams, is first dried at 100° in sand or asbestos, contained in a thin and fragile 
round-bottomed evaporating-shell (Hoffmeister's Schalchen). If desired, 
the moisture may be determined in this connection by loss in weight after 
dr}'ing. The shell is afterwards inclosed 1h a piece of fat-free filter- 
paper, and crushed in pieces between the fingers in such a manner as 
to avoid loss. The pieces are gathered in a mass and folded together 
in the filter-paper to form a packet of a size readily transferable to a 
Soxhlet extractor, in which the fat is removed in the usual manner and 
weighed, after drying, in a tared flask. 

Or, the fat may be indirectly determined as follows: The residue 
from the moisture determination is washed with 50 cc. of absolute 
ether or naphtha from the platinum dish into a flask, in which it is 
thoroughly shaken with the solvent, and then poured upon a weighed 
G3och crucible, containing previously ignited asbestos, or upon a tared 
filter. The flask is rinsed out and the residue on the Gooch or filter 
washed free from fat with fresh portions of ether or naphtha, which may 
conveniently be contained in a wash-bottle. t The Gooch or filter is then 
dried at 100° to constant weight and weighed, the fat being determined 
by difference. 



* U. S. Dept. of Agric, Div. of Chem., Bui. 46, p. 43. 
■j" Recoven' of the ether may be effected by distillation. 



EDIBLE Oils AND FATS. ■ 433 

Ash. — About lo grams of the butter are transferred to a tared flask 
of about loo cc. capacity, and its exact weight determined. About 50 cc. 
of ether or naphtha are then added, and the fat dissolved by shaking, pour- 
ing the solution upon an ash-free filter or on a tared Gooch. Wash out 
the flask and the residue on the filter with fresh portions of ether or naphtha, 
dry the residue, and if fiher-paper is used, transfer to a porcelain dish 
and burn to a white ash in a muffle or over a free flame, or burn the Gooch 
directly. Cool in a desiccator and weigh. 

Casein. — Proceed with 10 grams of the fat as in the preceding section 
up to the point of washing the residue upon a filter. Dry the residue 
on the filter and determine the nitrogen according to the Gunning method, 
making a blank test on the filter and reagents: 

Nitrogen X 6.37 = casein. 

Milk Sugar and Lactic Acid compose most of the undetermined 
matter remaining after deducting from the total solids the sum of the 
fat, casein, and ash. Determine milk sugar, if desired, in an aqueous 
extract of the butter by Fehling's solution. 

Determination of Salt. — In a tared dish or beaker weigh out about 
5 grams of butter, taking a gram or so at a time from different parts of 
the sample. Add hot water to the ^veighed part, and after it has melted, the 
contents of the dish are poured into a separatory funnel, shaken and 
allowed to stand till the fat collects at the top, after which the underlying 
aqueous solution is drawn off into an Erlenmeyer flask, leaving the fat 
in the funnel bulb. Hot water is again added, and from ten to fifteen 
extractions are made, using about 20 cc. of water each time, all the water 
being collected in the Erlenmeyer flask. 

A few drops of a solution of potassium chromate are then added for 
an indicator, and the sodium chloride volumetrically determined by a 
standard silver nitrate solution. 

Sal.ed butter contains from 0.5 to 6% of salt. 

Examination of Butter Fat. — The butter fat is best obtained free 
from curd and salt by filtering when hot, the sample being best melted 
in a beaker on the water-bath. The water, with the curd and sah, will 
settle to the bottom. The clear fat is then filtered at a temperature not 
exceeding 50° C., and subjected to such examination as may be desired 
to determine its purity. 

U. S. Standard Butter Fat has a Reichert-Meissl number not less 

40° 
than 24 and a specific gravity not less than 0.905 at — 5 C. 

40 



434 FOOD INSPECTION /IND ANALYSIS. 



ADULTERATION OF BUTTER. 

The artificial coloring of butter is an art practiced for so many years, 
and is so far in accord with the popular demand, that it can hardly be 
considered as an adulteration. The most recent custom of adding pre- 
servatives other than salt to butter is, however, very properly considered 
in most localities as reprehensible, unless the character and amount of 
the preservative be made clear to the purchaser by a suitable label. 

The most common and time-honored sophistication is the substitu- 
tion in whole or in part of foreign fat, as in the case of oleomargarine, 
and, more recently, in the fraudulent sale of renovated or process butter 
for the freshly made article. 

U. S. Standard Butter is butter containing not less than 82.5% of 
butter fat. 

Artificial Coloring Matter in Butter.— Formerly carrot juice 
and annatto were used almost entirely as butter colors. The carrot furnished 
to the farmer a ready means of coloring his dairy butter, and its use was 
long in vogue for this purpose, before the commercial butter colors were 
available. Other vegetable colors, such as turmeric, marigold, saffron, 
and safflower, are said to have been used for this purpose, but, with the 
possible exception of turmeric, the writer is not aware of authentic cases 
in which they have been found in recent years. While annatto as a butter 
color is still in use, it is rapidly giving place to various oil-soluble, azo coal- 
tar colors, which are admirably adapted to the purpose. All butter 
colors are now put on the market in solution in oil, usually cottonseed 
in this country and sesame in Europe. 

Detection. — Martin* devised a general scheme, applicable for the 
detection of various colors in butter. His reagent consists of a mixture of 2 
parts of carbon bisulphide with 15 parts of ethyl or methyl alcohol. 25 cc. of 
this solution are shaken with about 5 grams of the butter to be tested, and, 
after standing for some minutes, the mixture separates into two layers, of 
which the lower consists of the fat in solution in the carbon bisulphide, 
while the upper is the alcohol, which dissolves out and is colored by the 
artificial dye employed. If saffron is present, the alcoholic extract will be 
colored green by nitric acid and red by hydrochloric acid and sugar. 

Coal-tar dyes, if present, may be fixed on silk or wool by boiling bits 
of the fiber in the alcoholic extract, diluted with water and acidulated 
with hydrochloric acid. 

* Analyst, 12, p. 70. 



EDIBLE OILS AND FATS. 435 

Turmeric is to be suspected, if ammonia turns the alcoholic extract 
browTi ; marigold, if silver nitrate turns it black, and annalto, if on evapo- 
rating the alcoholic solution to dryness and applying to the residue a drop 
of concentrated sulphuric acid, a greenish-blue coloration is produced. 

Turmeric is further tested for in the residue from the alcoholic extract 
as above obtained, by boiling the residue in a few cubic centimeters of 
a dilute solution of boric acid (or a solution of borax acidulated with 
hydrochloric acid), and soaking a strip of filter-paper therein. On drying 
the paper, if it assumes a cherry-red color, turning dark olive by dilute 
alkali, the presence of turmeric is assured. 

Carrotin (the coloring matter of the carrot root) does not impart its 
color to the alcohol layer in Martin's test. Moore * has pointed out 
this exception, and shown that while \vith carrotin present the alcohol 
layer in Martin's test remains colorless, as in the case of uncolored butter, 
that when, however, a drop of very dilute ferric chloride is added, and the 
test-tube shaken, if carrotin be present, the alcohol will gradually absorb 
the yellow color from the butter. Care must be taken to avoid an excess 
of ferric chloride, as very little of this reagent will suffice. 

Allen states that a butter color commercially known as "carrotin" 
consists in reality of i part of annatto in 4 parts of oil. 

Detection of Annatto in Butter. — Treat 2 or 3 grams of the melted 
and filtered fat (freed from salt and water) with warm, dilute sodium 
hydroxide. After stirring, pour the mixture while warm upon a wet 
niter, using to advantage a hot funnel. If annatto is present, the filter 
will absorb the color, so that, when the fat is washed oi5 by a gentle stream 
of water, the paper will be dyed straw color. It is well to pass the warm 
alkaline filtrate two or three times through the fat on the filter to insure 
removal of the color. 

If, after drying the filter, the color turns pink on application of a 
drop of stannous chloride solution, annatto is assured. 

Detection of Coal-tar Colors in Butter. — Geislefs Method.^ — A few 
drops of the clarified fat are spread out on a porcelain surface and a pinch 
of fullers' earth added. In the presence of various azo-colors, a pink 
to violet-red coloration will be produced in a few minutes. Some varieties 
of fullers' earth react much more readily with the azo-dyes than do others. 
In fact some do not respond at all. When once a satisfactory sample of 
this reagent is obtained, a large stock should be secured of the same variety. 
Lcrw's Method.X — A small amount of material to be tested is melted 

* Analyst, 11, p. 163. -j" Jour. Am. Chem. Soc, 20, 1898, p. no. J Ibid., 20, p. 889. 



435 POOD INSPECTION AND ANALYSIS. 

in a test-tube, an equal volume of a mixture of i part of concentrated 
sulphuric acid and 4 parts of glacial acetic acid arc added, and the tube 
is heated nearly to the boiling-point, the contents being thoroughly mixed 
by shaking; the tubes are set aside, and after the acid solution has settled 
out it will have been colored wine-red in the presence of azo-color, while 
with pure butter fat, comparatively no color will be produced. 

Doolittle's Method for Azo-colors and Annattc* — The melted sample 
is first fihered. Two test-tubes are taken and into each are poured about 
2 grams of the filtered fat, which is dissolved in ether. Into one test- 
tube are poured i or 2 cc. of dilute hydrochloric acid, and into the other 
about the same volume of dilute potassium hydroxide solution. Both 
tubes are well shaken and allowed to stand. In the presence of azo- 
dye, the test-tube to which the acid has been added will show a pink 
to wine-red coloration, while the potash solution in the other tube will 
show no color. If annatto has been used, on the other hand, the potash 
solution will be colored yellow, while no color will be apparent in the 
acid solution. 

PRESERVATIVES AND THEIR DETECTION. 

Fresh or unsalted butter and renovated butter arc often found with 
an added preservative, the one most commonly used for this purpose 
being the so-called "boric mi.xture" (borax and boric acid) already dis- 
cussed under milk aduUeration. Salted butter is occasionally though 
not so often found preserved. Other preservatives used in butter are 
formaldehyde and salicylic and sulphurous acids. These latter are, 
however, rarely found. 

Boric Acid. — This, if present, is best detected in the aqueous solution 
that settles to the bottom when butter is mehed at the temperature 
of the boiling water bath, the supernatant fat being decanted off. 
Richmond f claims to be able to distinguish free boric acid from borax 
as follows: If on applying turmeric-paper directly to the aqueous liquid 
the paper turns red, the color being especially evident on drying, free 
boric acid is indicated. As a confirmatory test the reddened turmeric- 
paper is treated with dilute caustic alkali, whereupon it turns a dark olive- 
green if boric acid is present. 

In the absence of a red color by the above test, or when this color is 

* U. S. Dept. of Agric, Bur. of Chcm., Bui. 65, p. 152. 
t Dain,' Chemistn', p. 254. 



EDIBLE OILS AND FATS. 437 

faint, the aqueous solution is acidified slightly with hydrochloric acid 
and the turmeric-paper applied as before. If borax be present to an 
appreciable extent, the red color will now be quite marked, even though 
not appearing before. In other words, testing with turmeric-paper with- 
out acidifying with hydrochloric acid shows, according to Richmond, 
a slight coloration due to the free acid alone, while the more intense color 
formed by first acidifying is due to the combined acid or borax. 

Determination of Boric Acid. — Ten grams of the butter fat are 
weighed in a beaker and transferred with hot water to a separator)^ funnel 
in which the fat is extracted with 10 to 15 portions of hot water as 
described on page 433. The combined aqueous extract is evaporated 
to dryness in a platinum dish, the residue made alkaline, and ignited at 
a dull red heat. Boil the ash with water, fiher, and wash with hot water, 
keeping the volume of the filtrate under 60 cc. Make sure that the solu- 
tion is perfectly neutral to methyl orange by treatment, if necessary, 
with sulphuric acid and tenth-normal alkali, add 30 cc. of glycerin, a 
few drops of the phenolphthalein indicator, make up to 100 cc, and 
titrate with tenth-normal sodium hydroxide according to Thompson's 
method (p. 669). 

Butter being practically free from phosphates, the preliminary treat- 
ment for removing phosphoric acid in Thompson's method may be 
omitted. 

Formaldehyde. — The aqueous solution from which the fat of the 
butter melted at low temperature has been poured off, is added to some 
milk previously found free from formaldehyde, and the test for the latter 
with hydrochloric acid and ferric chloride is tried directlv in the milk. 

Salicylic Acid. — Detection. — See method No. 2 for detection in milk, 
page 143- 

Determination oj Salicylic Acid. — Method oj the Paris Municipal 
Laboratory. — Repeatedly exhaust 20 grams of butter in a separatoiy 
funnel with a solution of Sodium bicarbonate, thas obtainin<^ soluble 
sodium salicylate, if salicylic acid be present. Acidulate the aqueous 
extract with dilute sulphuric acid, and extract with ether. Evaporate 
the ether, and to the residue add a little mercuric nitrate, forming a pre- 
cipitate nearly insoluble in water. Fiher this off, wash the precipitate 
with water, and decompose into free sahcylic acid with dilute sulphuric 
acid. Redissolve in ether, evaporate the solvent as before, and dry the 
residue at a temperature of 80° to 100°. E.xtract the residue with petroleum 
ether, dilute the ethereal liquid with an equal volume of 95% alcohol 



438 FOOD INSPECTION AND ANALYSIS. 

and titrate with tenth-normal alkah, using phenolphthalein as an indi- 
cator. 

I CO. of tenth-normal alkali = 0.0138 gram salicylic acid. 

Sulphurous Acid. — The aqueous liquid, separated from the butter fat, 
is distilled, and the distillate treated with bromine water and barium 
chloride. A precipitate on the addition of the latter reagent indicates the 
presence of sulphurous acid or a sulphite in the butter. 

Renovated or Process Butter. — This product is also variously termed 
"boiled," "aerated," and "sterilized" butter. There are various modi- 
fications of the process of manufacture, but the object is to melt up and 
treat rancid butter in such a manner that for a time at least it is sweet. 
The following manner of treatment is typical, and shows in the main the 
necessary steps in carrying out the process, though details of manipu- 
lation vary in different localities. 

The butter is melted in large tanks surrounded with hot water jackets 
at a temperature vaiying from 40° to 45° C. By this means the curd 
and brine settle to the bottom, whence they are drawn off, while the lighter 
particles rise to the top in the form of a froth or scum and are removed 
by skimming. 

The clear butter fat is then, as a rule, removed to other jacketed 
tanks, and, while still in a molten condition, air is blown through it, which 
removes the disagreeable odors. The melted fat is then churned with 
an admixture of milk (more often skimmed) till a perfect emulsion is 
formed, after which it is rapidly chilled by running into ice cold water, 
with the result that it becomes granular in form: It is then drained 
and "ripened" for some hours, after which it is worked free from excess 
of milk and water, salted, and packed. 

Under some state laws this product, to be legally sold, must conform 
to rules of labeling as strict as those prescribed for oleomargarine. In 
other localities it may be sold with impunity. It is not infrequently 
put on the market as the very choicest creamery butter, and sometimes at 
the same price. 

U. S. Standard Renovated or Process Butter is renovated or process 
butter containing not more than 16% of water, and at least 82.5% of 
butter fat. 

Oleomargarine or Butterine. — These terms are applied in the United 
States to artificial butter composed wholly or in part of fat not produced 
exclusively from milk or cream. The product is commonly known in 
England as margarine. Though butter substitutes are known to exist 



EDIBLE OILS AND FATS. 439 

composed entirely of fat other than that derived from milk or cream, 
they are comparatively rare. As a rule the oleomargarine of commerce 
is composed of refined oleo oil, usually churned up with neutral lard, 
milk, and a small amount of pure butter, the whole being salted and 
sometimes colored to resemble butter. 

Oleo oil is prepared from the fat of beef cattle somewhat as follows : * 
Immediately after the animals are killed the fresh intestinal and caul 
fat are removed and placed in tanks of water at a temperature of about 
80° F. From this water they are transferred to other tanks of cold water 
and chilled until all animal heat is removed. The fat is then cut or 
hashed into small pieces and melted at about 150° F. in jacketed steam 
kettles, until the clear oil is entirely separated from the connective 
tissue. 

This oil is then drawn off into vats, wliich, on account of the appear- 
ance of the oil on cooling, are called graining or seeding vats, where it 
is allowed to stand for twenty-four hours or more at a temperature of 
about 85° F. From these vats the semi-solid emulsion of oil and stearin 
is dipped into cloths, which are folded and placed in a press between sheets 
of metal and subjected to powerful pressure. By this means the oil 
is separated from the stearin, and is drawn into casks for export or for 
manufacture into oleomargarine. Large quantities are annually exported 
to Holland, where oleomargarine is manufactured, and either sold for 
consumption in that country, or re-exported to other countries in Europe. 

The oleo oil thus expressed is a mixture of olein and palmitin. When 
first prepared, it is a clear amber-colored fluid, free from odor or fatty 
taste. It is packed in tierces, and, wlien opened at ordinary temperature, 
is a light-yellow solid. 

The further process of manufacture of oleomargarine consists in 
the main of mixing the oleo oil as above obtained with varying propor- 
tions of neutral lard, milk, and genuine butter, with or without added 
coloring matter, and churning the mixture at a temperature above the 
melting-point of the fats, the neutral lard having previously been cured 
for at least forty-eight hours in salt brine. Occasionally small quantities 
of other vegetable oils, as cottonseed, peanut, or sesame, are included in 
the above mixture. After the churning, the whole mass is cooled by 
contact with ice water. The chilled mass is drained, and afterwards 
salted, worked, and given much the same treatment as butter. 

* Report on Oleomargarine, Its Manufacture and Sale, 19th An. Report, Mass. St. Bd. 
of Health, 1887. 



440 FOOD INSPECTION /fND ANALYSIS. 

The composition of commercial oleomargarine varies between the 
following limits: 

Oleo oil 20 to 25% 

Neutral lard 40 " 45% 

Butter 10 " 25% 

Milk, cream, salt, etc 5 " 30% 

The artificial coloring matters employed for oleomargarine are the 
same as in the case of butter, and are similarly tested for. 

In many states oleomargarine cannot be legally sold when colored 
to resemble butter. Under other state laws coloring matter is allowable. 
The federal law and most state laws prescribe the most rigid rules for 
marking packages containing oleomargarine, with a view to affording 
the utmost protection to die producer of butter against the fraudulent 
substitution therefor. 

Healthfulness of Oleomargarine.^Under the directions of the Massa- 
chusetts Board of Health,* a large number of artificial digestion experi- 
ments were made to show the relative nutritive value of butter and oleo- 
margarine, and at the same time the wholesomeness of oleomargarine 
as a food was carefully investigated. The general conclusions reached 
were that, when comparing the best grades of both products, there is 
little if any difference between butter and oleomargarine on grounds of 
digestibility, while a good oleomargarine is much to be preferred to a 
poor butter from a nutritive standpoint. As to its wholesomeness, a 
large number of experts consulted were unanimous in expressing their 
favorable opinions of oleomargarine as a healthful article of food. 

When sold on its own basis in accordance with the law, it forms an 
excellent cheap substitute for butter. It is only when fraudulently sold 
as butter or in violation of the various state and federal laws, that it 
comes within the province of the health authorities to condemn it, and, 
unfortunately, by reason of its close resemblance to the dairy product 
the temptation to sell it for what it is not is always great. 

Distinguishing Oleomargarine from Butter. — The two products, 
made up as they are of mixtures of the same fats, and differing for the 
most part only in the percentage composition of these fats, show many 
properties in common. For instance, the melting-point is so nearly the 
same for both products as to be of no use as a distinguishing indication. 
Other physical characteristics, as of taste and smell, are very similar in 
both products, except in the hands of the expert. The microscope is 

* igth An. Report, Mass. State Board of Health.. 1887, p. 248. 



EDIBLE OILS AND FATS. 



441 



of limited value, except in so far as it indicates that the fat has first been 
melted and afterwards solidified. 

From the fact that oleo oil and neutral lard form by far the larger 
portion of the mixture known as oleomargarine, the glycerides that make 
up the fat of the latter are chiefly those of the insoluble fatty acids, stearic, 
oleic, and palmitic. The percentage of volatile fatt}f acids present in 
oleomargarine is very small, and the presence of these volatile acids is 
due entirely to the admixture of butter which it contains. This furnishes 
the most ready means of distinguishing chemically between the two 
products, and, as indicated by the Reicheii number, is the chief reliance 
of the analyst for court evidence. 

Incidentally, as will be seen by the accompanying table, the refrac- 
tometer reading, the iodine number, the saponification equivalent, and 
the specific gravity are all useful constants in indicating points of differ- 
ence between the two fats, it being understood that in oleomargarine, 
as in butter, the fat for examination is melted and separated by filtra- 
tion or otherwise from the curd, salt, and other constituents. 



CONSTANTS OF BUTTER FAT AND OLEOMARGARINE. 





>■ . 

02" 







"a 

<! 
m 


i 


"2 
■3 
c 

■§ 

< 


•H 

c3 


'ii 

p 


* 

.■Si 


u 

a; 


t 

I 
E 
(2 


Butter fat: 

Maximum 

Minimum 

Oleomargarine, 


o.870§ 
.867§ 

.862S§ 


3l.SSt 
4 -441 

11.69! 
9.34t 


89.6ot 
Ss.63t 

92.46t 
95-45t 


S.94t 
3.oot 

i.l6t 
0.1 2i 


S.62t 
o.ooj 

3.64t 


.87St 
.i7St 

.35ot 
.3063! 


3. lot 24I§ 
o.49t 253§ 

o.74t 277§ 


IS. St 

I2.4T 

S.5t 
o.st 


47. 7t 
44 -St 

S4.8t 
53 ot 


35° 




■8s85§ 















* Number of cubic centimeters N 'to alkali neutralizing volatile acids in 2.5 grams fat. 

t From analyses made in Mass. State Board of Health laboratory. 

t From analyses made in laboratory of U. S.' Dept. of Agric, Bur. of Chem. 

§ From analyses by A. H. Allen. 

The constants for varying mixtures of butter with foreign fat as found 
by Villiers and Collin || are tabulated on page 442 . 

Odor and Taste. — It is easy with a little practice to become so 
accustomed to the odor and taste of oleomargarine, as to be able to pass 
judgment with considerable confidence by these senses alone, whether 
a sample in question is oleomargarine or butter. The distinction is 
rendered more apparent by melting a portion of the sample on the water- 
bath. If the product is butter, either fresh or renovated, the butyric 
odor of the melted fat is very characteristic, while the melted oleomargarine 

II Les Substances Alimentaires, p. 731. 



44-! 



FOOD INSPECTION AND ANALYSIS. 



not only is lacking in the butyric odor (a negative property), but possesses 
a distinctive "meaty" smell peculiar to itself, which, while not unpleasant, 
is unmistakable. The flavor of oleomargarine to one experienced in dis- 
tinguishing between the two produces is very apparent. This flavor, 
slight though it is, might be compared to that of cooked meat. 









Hehner's 


Soluble 


Koettstorfer's 


Volatile 








Number. 


Acids. 


Equivalent. 


Acids. 


Pure butter 


88 


5 


224 


26 


Butter, 9S%; 


foreign fat 


5%.... 


!^^5 


4-8 


222.6 


24-7 


" 00^7 


< 1 n 


10%.... 


88.70 


4.5 


221.2 


23-4 


" 85% 


n n 


15%---- 


89.05 


4-3 


219.8 


22.2 


80% 


it (( 


20%.... 


89.40 


4-1 


218.4 


20.9 


" 75% 


it tt 


25%---- 


89-75 


3-9 


217 


ig.6 


" 70% 


( ( ( ( 


30% 


90.10 


3-6 


2IS.6 


1S.3 


" 6^% 


1 c (t 


35% 


90-45 


3-4 


214.8 


17. 1 


bo<^c 


tt (1 


40%.---- 


90.80 


3-2 


212.8 


15-8 


" iS% 


It ft 


45%---- 


91-15 


3 


211. 4 


14-5 


" S°% 


tt 1 1 


50%-... 


91-50 


2-7 


210 


13-2 


" 45% 


tt 't 


55%---- 


91.85 


2-5 


20S.6 


12 


" 40% 


Ct tl 


60% .... 


92.20 


2-3 


207.2 


10.7 


" 35% 


tt CI 


65%-- •■ 


92-55 


2.1 


205-8 


9-4 


'■ 30% 


It tt 


70%.... 


92.90 


1. 8 


204.4 


8.1 


" 25% 


It It 


75%--.. 


93-25 


1.6 


203 


6.9 


" 20% 


(f tt 


8or..... 


93.60 


1-4 


201.6 


5.6 


" 15% 


tt 1 1 


85%.... 


93-95 


1.2 


200.2 


4-3 


" 10% 


tt l( 


90%.... 


94-30 


0-9 


198.8 


3 


" . 5% 


tl (1 


95%---- 


94-65 


0.7 


197-4 


1.8 


Foreign fat. . 






95 


0-5 


196 


0-5 









Distinguishing between Butter, Process Butter, and Oleomargarine.^ 

With the increased occurrence in the market of the commercial product 
known as "process" butter, especially in localities where its sale is 
restricted or regulated by law, it becomes incumbent on the analyst to 
distinguish it from the other products which it resembles. 

As a rule, the tests, chiefly physical, that are applied on the edible prod- 
uct as a whole (i.e., without separation of the curd, salt, etc.), such as the 
foam test, the milk test, the microscopical examination, and the appear- 
ance of the melted sample, distinguish broadly between pure fresh butter 
on the one hand, and oleomargarine on the other. In other words, al- 
though there are those skilled in making the above tests who claim to 
be and doubtless are able to note distinguishing features between oleo- 
margarine and process butter, yet these two products respond alike, 
though perhaps in var>'ing degrees, to these tests, and are classed together 
as distinguished from pure butter. 

On the other hand, such tests as depend upon the refractometer, 
the Reichert number, and, indeed, all the so-called chemical constants, 



EDIBLE OILS /IND F^TS. 443 

which are apphed to the separated fat, freed from other substances, will 
serve to distinguish between oleomargarine and butter, whether "pro- 
cess" butter or otherwise, since the "processing" or "renovating" of 
butter does not change the character of its fat sufficiently to materially 
alter these constants. 

It is best, therefore, for purposes of routine preliminary separation 
to submit all samples to the "foam" test and to examine them by the 
butyro-refractometer.* These tests alone, which are very quickly and 
readily applied, will rarely fail to separate into the three classes, butter, pro- 
cess butter, and oleomargarine, the products under examination, after which 
such confirmatory tests as are desired are made on adulterated samples. 

The Butyro-refractometer. — This instrument, as its name implies 
was primarily intended by Zeiss for the examination of butter, and, while 
its use has been extended for work with other fats and oils, its construc- 
tion is such as to show particularly a distinction between butter and 
oleomargarine by the appearance of the critical line of the fat. This 
mode of differentiation is due to the peculiar construction of the double 
prism, which shows differences of dispersive power by different appear- 
ances of the critical line. The prisms are so constructed that the 
critical line of pure butter is colorless, while margarine and artificial 
butter, which have greater dispersive powers than natural butter, show 
a blue-colored critical line. But anomalies in the color, both with pure 
butter and mixtures, are more or less observable, which render it im- 
possible to draw a sharp line lictween adulterated and genuine butter. 
The appearance of a blue fringe may, however, be a useful factor in 
cases of suspected adulteration. 

The following particulars respecting the application of the refractom- 
eter for analysis of butter are contained in a paper of Dr. R. Wollny of 
Kiel,t who assisted in the construction of the instrument. The readings 
of the refractive indices of a large number of butter samples taken at 
25° C. by Dr. Wollny have been directly reduced to scale divisions and 
yield the following equivalents: 

* Out of the large number of samples of butter and oleomargarine examined on the 
butyro-refractometer in the author's laboratory during eight years, he has never found a 
single instance where the instrument failed to show the difference between the two products. 

t Dr. R. Wollny, Schlussbericht iiber die Butteruntersuchungsfrage, Milch wirthschaft- 
licher Verein, Korrespondenzblatt, No. 39, 1891, p. 15. 

Older papers on butter tests by refraction of light will be found in: Mueller, Rep. d. analyt. 
Chemie, 1886, pp. 346, 366. Skalweit, Milchzeitung, 1886, 15, p. 462. Wollny, Ueber die 
Kunstbutterfrage, Leipzig, 1887, p. 50. 



444 FOOD INSPECTION AND ANALYSIS. 

Natural butter. . .(1.4590- 1.4620): 49. 5 -54.0 scale divisions 
Oleomargarine. . .(1.4650— i.47oo):58. 6 — 66.4 " " 

Mi.xtures (artificial 
butter) (i. 4620-1. 4690)154. 0-64. 8 " 

Limit oj Scale Reading jor Pure Butter. — Whenever in the refracto- 
metric examination of butter at a temperature of 25° C. higher values 
than 54.0 are found for the critical line, these samples will, according 
to Wollny, by chemical analysis always be found to be adulterated; but 
with all samples in which the value for the position of the critical line 
does not reach 54.0 chemical analysis may be dispensed with, and the 
samples may be pronounced to be pure butter. Wollny suggests, as a 
means of removing all chances of adulterated butter escaping detection, 
that the above limit be placed still lower, and that all samples exhibiting 
values exceeding 52.5 (at a temperature of 25° C.) be set aside for chemi- 
cal analysis. 

lo calculating the position of the critical line for other temperatures 
than 25° C. allow per 1° C. variation of temperature a mean value of 
0.55 scale division.* The following table, which has been compiled 
in this manner, shows the values corresponding to various temperatures, 
each value being the upper limit of scale divisions admissible in pure 
butter: 



Temper- 


Scale 


Temper- 


Scale 


Temper- 


Scale 


Temper- 


Scale 


ature. 


Division. 


ature. 


Division. 


ature. 


Division. 


ature. 


Division. 


45° 


41-5 


40° 


44-2 


35° 


47.0 


30° 


49.8 


44° 


42.0 


39° 


44-8 


34° 


47-5 


29° 


5°-3 


43° 


42.6 


38° 


45-3 


33° 


48.1 


28° 


50.8 


42° 


43-1 


37° 


45-9 


32° 


48.6 


27° 


51-4 


41° 


43-7 


36° 


46.4 


31° 


49.2 


26° 


51-9 


40° 


44-2 


35° 


47.0 


30° 


49.8 


25° 


52-5 



If, therefore, at any temperature between 45° and 25° values be 
found for the critical line which are less than the values corresponding 
to the same temperature according to the table, the sample of butter may 
safely be pronounced to be natural, i.e., unadulterated butter. If the 
reading shows higher numbers for the critical line, the sample should be 
reserved for chemical analysis. 

Note. — Dr. Eichel of Metz has suggested that instead of comparing 
the scale divisions at the same temperature, the position of the critical 

* With natural butter this number is, as a rule, somevirhat less (0.53), with oleomargarine 
a little greater' (0.56). 



EDIBLE OILS AND F/ITS. 



445 



01 



line may be determined at the moment when the butter begins to set. 
In this case he gives fifty-four as the highest admissible number for the 
critical line of pure butter. 

No sharp distinction is apparent between pure and renovated butter 
on the refractometer. 

Special Thermometer for the Butyro-refractometer. — Instead of em- 
ploying the ordinaiT thermometer, as shown in Fig. 91, a special ther- 
mometer (Fig. 98) has been devised for work both with Q 
butter and with lard. This instrument has two scales, 
arranged side by side, one for butter and one for lard, 
each of which indicates at once the highest allowable reading 
for the pure fat, corresponding to the temperature at which 
the observation is made, which, however, need not be noted. 

If the scale reading of the instrument, as observed 
through the telescope, differs materially from the reading 
of the special thermometer, the fat under examination is 
undoubtedly adulterated, or, in the case of butter, a higher 
reading indicates oleomargarine. The special thermometer 
thus indicates the highest permissible number for pure butter. 

The Reichert or Reichert-Meissl Number * is by far the 
most important single determination in establishing proof 
of the character of the sample, whether butter or oleo- 
margarine, for evidence in court, and in such cases this 
determination is indispensable. The result is conclusive, 
excepting in those rare instances where the admixture of 
foreign fat is so small as to cause the Reichert number to pjg „g '^gpp^igl 
approximate that of pure butter. In common instances of Butyro-refrac- 
creamen' butter and commercial oleomargarine the Reichert '""^'*''^'' "" 

/- _ mometcr for 

number shows a very marked distinction (see table. Butter and 

p. 441). Lard. 

It is difficult to fix a minimum figure below which, in doubtful cases, 
a sample may be pronounced impure by reason of admixture with foreign 
fat. In general, however, a Reichert number under 10 would be almost 
sure to show adulteration, though instances are on record where butter 
of known purity has sho\vn a Reichert number even lower than this. 
It is in fact rare that pure butter has a Reichert number under 12. 

* The WTiter prefers to carrj- out this process on 2.5 grams of the butter fat, expressing 
thus the Reichert number, this being practically half the Reichcrt-Mcissl number, which is 
based on the use of 5 grams. 



446 FOOD INSPECTION AND ANALYSIS. 

Stebbins * gives the maximum, minimum, and average of the Reichert 
number obtained by him on 317 samples of unadulterated butter, some 
of which were of low grade, as follows: Maximum, 18.2; Minimum, 
1 1.2; Average, 14.7. 

As a rule little difference is apparent between pure and "renovated" 
samples as regards their Reichert number. 

Vieth has shown that the Reichert number of butter is generally a 
trifle lower after it becomes rancid. 

Specific Gravity. — Skalweit has shown that the specific gravity of 
butter and oleomargarine relative to each other varies with the temper- 
ature at which it is taken, the difference between the two growing less 
and less as the temperature increases above 35°. The greatest variation 
being at 35°, he recommends this temperature as the best at which to 
make the determination. 

The Foam Test, also known as the "boiling" or "spoon" test.f 
This, though originally intended as a household test, is in reality one of 
the very best laboratory methods of separating pure butter samples from 
renovated butter and oleomargarine. A small lump of the sample (from 
3 to 5 grams) is heated in a large spoon over a Bunsen flame, turned 
ver}' low, stirring constantly during the heating. Genuine butter, under 
these conditions, will boil quietly, but with the production of consider- 
able froth or foam, which will often swell up over the sides of the spoon, 
when, just after boihng, the latter is raised from the flame. Renovated 
butter or oleomargarine, under this treatment, will bump and sputter 
noisily like hot grease containing water, but will not foam.J Another 
point of difference is that on removing the spoon from the flame and 
observing the character of the curdy particles, in the case of genuine 
butter these particles of curd will be very small and finely divided in 
the melted fat, being indeed hardly perceptible, while with oleomargarine 
and renovated butter, the curd will gather in somewhat large masses or 
lumps. 

The test may be carried out in a test-tube if desired. 

The Waterhouse or Milk Test.§ — This test is based on the assump- 
tion that butter fat, which is in itself exclusively the product of milk, 
will mingle intimately with the milk when added thereto in a melted 

* Jour. Am. Chera. Soc, 21, 1899, p. 939. 
t Farmer's Bulletin, No. 131. 

% A very slight foam is sometimes observable with occasional renovated samples, but 
nothing like the abundant amount produced by the genuine product. 
§ Parsons, [our. Am. Chem. Soc, ^3, 1901, p. 200. 



EDIBLE OILS AND FATS. 447 

condition and cooled therein, whereas oleomargarine, being foreign to 
milk fat, will, under like conditions, refuse to diffuse itself naturally 
in milk as a medium. 

About 50 cc. of well-mixed sweet milk are heated nearly to boiling 
in a beaker, and from 5 to 10 grams of the fat sample are added. The 
mixture is then stirred, preferably with a small wooden stick, until the 
fat is melted. The beaker is then placed in a dish of ice cold water, and 
the stirring continued till the fat reaches the solidifying-point, at which 
period, if the sample is oleomargarine, the fat can readily be collected 
by the stirrer into one lump or clot, but, if butter, it cannot be so collected, 
but remains in a granulated condition, distributed through the milk 
in small particles. It is not necessary to keep up the stirring through 
the entire term of cooling, but to begin stirring before the fat starts to 
solidify, which should require from ten to fifteen minutes after the mixture 
is placed in cold water. 

This test, if carefully carried out, shows a marked distinction between 
butter, whether pure or renovated, and oleomargarine. Under certain 
conditions, as when the cooling is too rapid, samples of renovated butter 
fat will sometimes show a slight tendency to clot together as in the case 
of oleomargarine, but to no such extent as the latter. 

The author's experience with this test has shown it to be very reliable 
not only in identifying oleomargarine from butter, but in nearly every 
case renovated butter can be distinguished from genuine. As a rule, 
genuine butter fat, even after cooling to the solidifying-point, shows the 
greatest tendency to emulsionize with the milk when stirred, without 
adhering to the wooden rod, and is slow to come to the surface when 
the stirring is stopped. Renovated butter fat, when stirred in the cold 
milk, almost instantly gathers in a film on the surface of the milk when 
the stirring is stopped, without emulsionizing. It does not clot together 
like oleomargarine, but it tends to adhere to the wooden rod. 

Patrick * recommends the use of skimmed or partially skimmed 
milk, and heats to the boiling-point after the fat has been introduced 
into the hot milk. 

Examination of the Curd. — The curd of genuine butter is made up 
largely of such of the milk proteids as are insoluble in water and hence 
pass into the cream when separated. These proteids form a gelatinous 
mass in the butter, readily clotting together when the fat is melted. On 
the other hand, the curd of process butter, which is, as it were, artificially 

* Farmer's Bulletin, No. 131. 



44S FOOD INSPECTION AND ANALYSIS. 

derived from the entire or skira milli used in its manufacture (in order 
to replace the natural curd which has been removed in the "purifying" 
process), differs from the proteids of cream in that it is granular and 
flaky, consisting chiefly of coagulated casein. Hence the distinction 
noted as to the appearance of the curd in the foam test. 

For the same reason, if beakers containing pure and renovated butter 
are melted on the water-bath, the curd of the pure sample will settle at 
once, or in a very few minutes, to the bottom after melting, leaving a 
comparatively clear supernatant fat. The renovated sample will nearly 
always fail to settle out clear, even after standing on the water-bath for 
half an hour or more, but will still be cloudy throughout the mass, due 
to particles of non-cohesive, floating curd. 

In the case of oleomargarine, the curd of which is composed partly 
of pure butter curd (from cream proteids) and partly of the proteids 
of the milk with which it is churned, the cloudiness of the fat on melting 
depends on the relative proportion of milk proteids, and in general is not 
especially characteristic. 

Identification of the Source of the Curd.*^Half fill a small beaker 
with the sample and melt on the water-bath. Decant as much as possible 
of the fat and pour the rest, consisting largely of the water, salt, and 
curd, upon a wet filter. Acidify the filtrate, which contains the salt 
and soluble proteids, with acetic acid and boil. If the sample is pure 
butter, only a slight milkiness is found, indicating absence of albumins, 
whereas, in the case of process butter, a white, flocculent albuminous 
precipitate is produced. 

Apply to the filtrate also Liebermann's test for albumin; i.e., add 
strong hydrochloric acid. If a violet coloration is produced, the sample 
is presumably "process" butter. 

Microscopical Examination of Butter. — Considerable information may 
in general be gained by an examination of the sample under ordinary 
light and with a rather low power, say from 120 to 150 diameters. For 
examination in this way a bit of the sample on the edge of a knife blade 
is placed on the glass slide, and simply pressed lightly into a thin film 
by the cover-glass. A very characteristic difference between genuine 
and renovated butter is at once seen in the relative opacity of the fields. 
The fat film, in the case of fresh, pure butter, is much more transparent 
than that of the renovated. Again, the curd is so finely divided through- 
out the mass of genuine butter fat that the field is much more even than 

* Hess and Doolittle, Jour. Am. Chem. Soc, 22, iqoo, p. 151. 



EDIBLE OILS AND FATS. 449 

that of the renovated, wherein often large and opaque patches of curd 
are frequently distributed throughout the field. 

When a renovated butter sample, mounted as above, is viewed hy 
reflected light, for which purpose the microscope mirror is turned so as 
not to transmit light through the instrument, one sees a very dark and 
scarcely perceptible field; but the opaque patches of curd above referred 
to are strikingly apparent as white masses against a dark background. 

With Polarized Light. — It has already been stated that the micro- 
scope is useful in showing whether or not a fat has been melted, the 
crystalline structure of the fat once melted and afterward cooled being 
rendered apparent, especially when viewed by polarized light. This 
fact has long been known and put to practical use in the identification 
microscopically of butter and oleomargarine.* 

When viewed by polarized light between crossed Nicols under a 
low magnification, pure butter not previously melted should show no 
crj-stalline structure, being uniformly bright throughout, and, if the 
selenite plate be used, should present an evenly colored field, entirely 
devoid of fat crystals. On the other hand, with process butter or oleo- 
margarine, both of which have been melted and subsequently cooled, 
the crystaUine structure should be marked, showing with polarized light 
a more or less mottled appearance, and a play of colors with the selenite. 

Various conditions enter in to affect the reliability of the polarized light 
test. It is nearly always possible in cold weather to observe these dis- 
tinctions in practice, as above described, in a sharp and striking manner. 
Figs. 269, 270, and 271, PI. XXXVIII, show typical fields of the three 
products with crossed Nicols and selenite plate. The appearance of pure 
butter is perfectly blank, while oleomargarine presents a much more 
mottled appearance than renovated butter. Such well-defined points 
of variation as are shown in Plate XXXVIII are not always to be seen 
in practice, even in the hands of an expert. Pure butter sometimes 
exhibits a somewhat mottled field, due to a slight crystallization at some 
period in its history. In the summer-time, for instance, when butter 
melts so easily at ordinary temperature, these distinctions between pure 
and adulterated samples as shown by polarized light are by no means 
as satisfactory as in the winter. 

Great care should be taken on this account, on the part of the col- 
lector of samples as well as the analyst, to keep the sample from melting 
imder ordinary conditions before it is examined. 

* Hummel, Jour. Am. Chem. Soc, 22, p. 327; Crampton, loc. cit., supra, p. 703. 



45° FOOD INSPECTION AND ANALYSIS. 

Hess and Doolittle's Method of Examining the Curd.* — A convenient 
portion of the sample of suspected butter is melted in a beaker, as much 
of the fat as possible is decanted off, and the remaining curd, washed 
free from fat with ether, is poured out on a glass plate and dried. A 
sample of pure butter is treated in like manner by way of comparison- 
When examined under a very low magnification of from 3 to 6 diameters, 
the curd from the pure sample will be seen to be non-granular 
and amorphous in appearance, while, in the case of renovated butter, 
the curd will appear very coarse grained and mottled. 

Zega's Test for Oleomargarine.f— A portion of the filtered fat is 
poured into a test-tube and kept for two minutes in a boiling water-bath. 
I cc. of this fat is then measured with a hot pipette into a 50-cc. tube con- 
taining 20 cc. of a mixture of 6 parts ether, 4 parts alcohol, and i part 
glacial acetic acid. The tube is stoppered, shaken well, and cooled in 
•water at 15° to 18° C. In the case of pure butter fat, the solution remains 
clear for some time, a slight deposit being apparent only after standing 
an hour or more. With oleomargarine, a deposit is evident in a very 
short time, and in ten minutes a heavy precipitate comes down. With 
10% of oleomargarine in butter, a separation occurs in about fifteen 
minutes. When a few solid particles have separated out, they are with- 
drawn and examined under the microscope. With genuine butter, long 
narrow rods appear, sometimes pointed at the ends, often bent, and grouped 
as a rule centrally in star-shaped bundles. Oleomargarine presents an 
appearance of bundles of fine needles, closely packed to form masses 
frequently resembling sheaves and dumb bells in shape. 

Identification of Various Oils and Fats. — Cottonseed oil may be 
recognized, if present in butter or its substitutes, by the Halphen test, 
and sesame oil by the Badouin test. Peanut oil is tested for by the 
Bellier or Renard test. 

Cocoanut oil is sometimes said to be present in butter substitutes. 
It has a higher Reichert number than most adulterants, and hence a 
larger admixture of this than of other foreign fats could be used, without 
lowering the Reichert number of the whole below the allowable limits 
of pure butter. Its presence would, however, be rendered apparent 
by the low iodine and refractometer numbers. 

Glucose in Butter.J — Crampton states that glucose has been found by 
him in butter intended for export to tropical countries, added to pre- 

* Jour. Am. Chem. Soc, 22, 1900, p. 151. 

t Chem. Zeit., 1899, 23, 312; Abs. Analyst, 24, p. 206. 

X Jour. Am. Chem. Soc, 20, 1898, p. 201. 



EDIBLE OILS AND FATS. 45 1 

vent decomposition. In one sample made for export to Guadeloupe 
he found over io% of glucose. 

For its detection or estimation lo grams of the sample are weighed 
out and transferred to a separatory funnel with hot water, and shaken 
out with successive portions of hot water. These are combined, and 
the aqueous extract made up to 250 cc. The reducing sugar may be 
determined by Fehling's solution or by polarization, using in the latter 
case alumina cream as a clarifier. While a slight reduction should be 
disregarded, any considerable reduction may be undoubtedly ascribed 
to glucose. 

Adulterants of Oleomargarine. — This product is liable to adultera- 
tion not only by the use of inferior and unwholesome fat, but by the admix- 
ture in some cases of paraffin.* This sophistication is made manifest, 
if an appreciable amount of the adulterant has been used, by the high 
melting-point and the low saponification number, as well as by the low 
specific gravity. If a clear saponification is impossible under ordinary 
conditions, paraffin is to be suspected. It may be separated and quanti- 
tatively determined as described on p. 409. 



LARD. 

Nature and Composition. — Lard is the fat of hogs, separated by heat 
from the scraps or containing tissues. The choicest or highest grade of 
lard is known as leaf lard, and is derived from the fat which surrounds 
the kidneys. A comparatively small part of the lard of commerce is, 
however, strictly speaking, pure leaf lard. Most of it is derived from 
the whole fat of the animal by rendering, by the aid of steam under 
pressure, either in open kettle or in closed tanks, the former being used 
more often for rendering lard on a small scale, and the latter being the 
most common commercial method. 

Next to the leaf, the fat from the hog's back is considered the best 
in quality, after which is graded, in the order named, the fat from the 
head, the region of the heart, and the small intestines, the last two grades 
constituting what is commonly known as "trimmings." 

Good lard is white and granular, having the consistency of salve. It 
has an agreeable, characteristic odor and taste. 

The leaf or kidney fat furnishes also the source of the so-called neutral 
lard, already mentioned as an ingredient of oleomargarine. The leaf, 

* Geissler, Jour. Am. Chem. Soc, 21, p. 605. 



452 



FOOD INSPECTION /IND ANALYSIS. 



being first chilled and finely ground, is placed in the kettle and ren- 
dered at a temperature of from 40° to 50° C, at which heat only a portion 
of the lard separates. This portion is, while melted, washed with water 
containing sak or dilute acid, and forms the neutral lard, a product 
almost entirely free from odor. The remainder of the leaf is then trans- 
ferred to the closed tank and subjected for some hours to steam under 
pressure at a temperature of 230° to 290° F., the resulting lard being 
graded as pure leaf lard. 

The composition of the mixed fatty acids of lard is thus calculated 
by Twitchell: 

Linoleic acid 10.06% 

Oleic acid 49-39% 

Solid acids (by difference), stearic and palmitic .. 48.55% 

Lewkowitsch * gives the following constants for American lards made 
from fat from different parts of the animal : 





Specific 

Gravity 

at 100° C. 

(Water at 

iS°C. = i.) 


Iodine 
Value. 


Maumen^ 

Number at 

40° C. 


Melting-point, Bense- 
mann'st Method. 


Refractive 
Index. 


Fat from 


Temp. C. 

of Incipient 
Fusion. 


Melted to 
a Clear 
Drop. 


Butyro- 

refractom- 

eter at 

40° C. 


Head 


0.8637 
0.8629 
0.8631 
0.8611 
0.8621 
0.8616 
0.8637 
0.8615 
0.8700 
0.8589 
0.8641 
0.8615 
0.8628 


66.2 
66.6 
65.0 

61.5 
65.0 
65.1 
62.2 

59 -o 
63.0 
68.8 
68.4 
66.6 
68.3 


33 
32 
34 
37 
35 

38 

30 

38 


24 
24 
24 
28. 5 
28. 5 

31-5 

26 

29 

28.S 

24 

26 

26 

26 


44.8 
44.8 
45-° 
48. 5 
48.5 
46 . 
45 
44 

44-5 
40 

45 
44 
44-5 


52.6 


Back 


52-5 
52.0 

52-4 


Leaf 


Si-8 
Si-9 

51-4 


Foot 


50.2 
52.0 
44.8 


Ham 


51-9 




51-9 
S3-0 


Ham (German) 


0-8597 


SS-o 


30 


32 


46 


49-2 



Lard Oil. — This oil is obtained by subjecting lard contained in woolen 
bags to hydraulic pressure in the cold. The lard oil (chiefly olein) 
thus expressed constitutes nearly 60% of the whole, and the residue 
is known as lard stearin. 

Lard oil is a thin fluid, pale yellow in color, and with varying specific 

* Oils, Fats, and Waxes, p. 568. 

t Bensemann distinguishes between the temperature at which the fat begins to liquefy 
and that at which it becomes completely transparent. 



EDIBLF. OILS AND FATS. 453 

gravity, due to varj'ing conditions of pressure and temperature. It has 
a pleasant, though somewhat bland taste, and is used to some extent as 
an edible oil. It is used in France as an adulterant of olive oil, and 
with the Maumene, elaidin, and nitric acid tests, it behaves much like 
olive oil. 

According to the U. S. Pharmacopoeia, the specific gravity of lard oil 
should be from 0.910 to 0.920 at 15° C. 

At a temperature a little below 10° C. it should form a semi-solid 
white mass. 

When it is brought in contact with concentrated sulphuric acid, a 
dark reddish-brown color should instantly be produced. 

Lard oil should not respond to the Bechi test for cottonseed oil. 

If 5 cc. of the oil, contained in a small flask, be mixed with a solution 
of 2 grams of potassium hydroxide in 2 cc. of water, then 5 cc. of alcohol 
added, and the mixture heated for about five minutes on a water-bath 
with occasional agitation, a perfectly clear and complete solution should 
be formed, which, on dilution with water to the volume of 50 cc, should 
form a transparent, light-yellow liquid, without the separation of an 
oily layer (absence of appreciable quantities of paraffin oils). 

Adulterants of lard oil are cottonseed and corn oils. 

Compound Lard. — The article so extensively made and sold under 
this name is a mixture consisting usually of lard stearin, beef stearin, 
and cottonseed oil. Sometimes no lard whatever is present, but only 
a mixture of beef and cottonseed stearins. 

Lard stearin is the residue left in the cloths after the lard oil has been 
removed by pressure (p. 452). 

Beef stearin is, similarly, the residue from which oleo oil has been 
expressed (p. 439). The cottonseed oil used is highly refined, and finally 
decolorized by mixing with fullers' earth and filtering. 

U. S. Standards. — Standard Lard and Standard Leaf Lard are lard and 
leaf lard respectively, free from rancidity, containing not more than 1% 
of substances other than fatty acids, not fat, necessarily incorporated 
therewith in the process of rendering, and standard leaf lard has an iodine 
number not greater than 60. 

Adulteration of Lard. — The mixture known as "compound lard" 
is quite commonly fraudulently sold for pure lard. Indeed, the adul- 
terants of lard usually met with are cottonseed oil or stearin and beef 
stearin. Other oils said to have been used as adulterants are peanut, 
sesame, com, and cocoanut. Formerly water was incorporated into 



454 FOOD INSPECTION AND ANALYSIS. 

the fat to such an extent as to materially cheapen it, but this sophistica- 
tion is now rare. Moisture is determined as in the case of butter. 

The Butyro-refractometer Reading. — The refracting degree of cotton- 
seed oil on the butyro-refractometer is about 8.9 in excess of the standard 
refraction of lard, while that of beef tallow is about 3.8 less than the 
standard. If, therefore, the refractometer reading is unusually low, the 
presence of beef stearin is to be suspected; if unusually high, cottonseed 
oil should be looked for. A mixture of the two adulterants with pure 
lard such as is found in "compound lard," may sometimes, though not 
often, be found to give rcfractometric readings within the limits of pure 
lard. 

Detection of Foreign Oils. — Cottonseed oil is best detected by the 
Halphen test. A very slight color reaction should not be taken as proof 
positive of the admixture of cottonseed oil, since it has been found that 
the fat of hogs fed on cottonseed meal gives a slight reaction with both 
the Bechi and the Halphen tests. Sesame and peanut oils are detected 
by their special tests. Corn oil is indicated by the abnormally high 
rcfractometric reading and iodine number, cocoanut oil by the high 
Reichert number and the high saponification equivalent. 

Beef stearin is difficult to identify chemically, but is usually distin- 
guished by a microscopical examination of the fat after crystallization 
as follows: 

The Microscopical Examination of Lard. — From 2 to 5 grams of 
the fat are dissolved in 10 to 20 cc. of ether* in a test-tube, and the solu- 
tion allowed to stand 12 hours or over night at about 20° C, the test- 
tube being loosely stoppered with cotton. The crystals obtained vary 
considerably with the condition of heat, amount of solvent, rate of crys- 
tallization, etc., so that the operator had best vary these conditions till 
he is satisfied that the best possible results have been obtained. It is 
often advantageous to separate the crystals first obtained by filtration 
from the mother liquor, and to redissolve in ether and recrystallize in 
a second test-tube. The crystals formed at the bottom of the test-tube 
are, for the purpose of thus purifying, separated from the mother liquor 
by filtration through a small filter, and the precipitate washed several 
times with ether. The washing with ether should not be continued 
so long that the crystals are perfectly freed from mother liquor and olein, 
for in this case they are so dry and pulverulent as to require a mountant 
when on the slide for microscopical examination. The writer prefers 

* Some analysts get better results with a mixture of ether and alcohol. 



EDIBLE OILS AND FATS. 455 

to have them slightly oleaginous, so that when applied to the slide no 
mountant need be used. In this case the crystals seem to stand out in 
wider contrast to the background than when cottonseed oil, the usual 
medium, is used. 

If the crystals are, however, in a pulverulent condition, a drop of 
alcohol can be used as a mountant, or oil, as preferred. Mounted under 
a cover-glass they are examined under various powers of the microscope. 

Figs. 272 and 273, PI. XXXIX, show the typical appearance of 
pure lard stearin from a leaf lard of known purity, and Figs. 276, 277, 
and 278 illustrate beef stearin. These figures show distinctive crystal- 
lization of each form under the best conditions. The lard stearin 
crystals when thus obtained are flat rhomboidal plates cut oE obliquely 
at one end, and are grouped irregularly, as if thrown carelessly together. 
The beef stearin crystals, on the other hand, are cylindrical rods or 
needles, often curved, with sharp ends, and are arranged as shown in fan- 
shaped clusters. Conditions of crystallization are frequently such as not to 
show the sharp distinctions noted above. Both forms of crystals are at 
times apt to gather in clusters that at first sight appear somewhat 
similar, and are often misleading as to their true character. It is found 
almost invariably that the beef stearin crystals gather in clusters, radiat- 
ing from a common center or point, often with a peculiar twisted appear- 
ance, breaking up into little fans. Lard crystals, it is true, do not always 
lie flat in irregular groups as shown in Fig. 272, but, as in Fig. 274, form 
clusters that, unless studied carefully, might at first sight be considered 
as identical with the fan shapes of the beef stearin already described. 
It will be seen, however, that if the best possible conditions are attained, 
the crj'stals of lard, instead of radiating from a point, are arranged more 
like feathers or alternate leaves on a branch, each crystal being given forth 
from another close at hand. Moreover, the lard crystals are themselves 
straight and not curved, the apparent curve in the appearance of the 
clusters being, on careful examination, especially under high power, 
seen to be chiefly due to several of these straight crystals arranged at 
angles to each other. 

Even when the highest powers of the microscope are applied to the 
beef stearin crystals, they will always appear as cylindrical, sharp- 
pointed rods, some straight, others curved; while with the lard crystals 
they should be capable of showing the thin, flat, oblique-ended structure 
when examined with higher powers, even when they are arranged in the 
feathery clusters, the apparently pointed ends of some of the crystals 



456 



FOOD INSPECTION /1ND ANALYSIS. 



being due to the fact that the plates are viewed edgewise. This is apparent 
in Fig. 275, in which the crystals are magnified to 480 diameters. 

According to Belfield, who was one of the earliest to employ the micro- 
scope for identification of foreign fat in lard, it is possible to detect well- 
defined crystals of both lard and beef stearin in mixtures crystallized 
out in the above manner from ether. Later investigators, however, find 
difficulty in getting both kinds of crystals in the final deposit, it being 
the more common experience that the character of the final crystals from 
a mixture of the two fats more often tends to one or the other forms of 
crj'stallization. Repeated crystallizations may change the character of 
the crystals and a number of such crytallizations should therefore be 
made before final judgment is passed. 

The Iodine Number (p. 3S0). — This test is generally prefigured by 
the refracto meter. Cottonseed oil will absorb about 108% of its weight 
of iodine, while beef fat will absorb about 37%. 

ANALYSES OF SAMPLES ILLUSTRATING TYPES OF LARD, LARD SUBSTI- 
TUTES, AND MIXTURES. 



Nitric Acid Test. 



Crystallization. 



Bechi Reac- 
tion. 



Butyro-refrac- 
tometer. 



afc 

£q 



«; 



C o « 



Conclusion. 



A 
B 
C 
D 
E 
F 
G 
H 
I 



K 

L 

M 
N 



Slight color. . 
Red 

Slight color . 



Very slight color 
Deep-brown red 

Red 

Very slight color 
Deep brown . . . . 
Red 



Lard stearin 



Beef stearin 
Few small 

bunches 
Lard stearin 

Lard and 

beef stearin 
Lard stearin 



Lard and 
beef stearin 



None 



Deep color 
it (I 

None 
Deep color 



42-5 
42 

41-5 
43 

41-3 
42 

42 

5° 
42 

43 
43 

43-S 

43-7 
43-5 



49-7 

5° 

50.1 

5° 

51 

5°-5 
49-7 
41.2 

58.7 



5°-5 

48.5 

SI 

5°-i 
49-1 



4-O.I 
-1-0.2 

-1-0. o 

-1-0.6 
-1-0.8 
-1-0.7 

— o. r 
-3-8 
-1-8.9 

+ 1-3 

-0.7 

-l-i.i 

+ 1-3 
+ °-3 



58 
59 
58 
63 
64 
64 

56.4 
37-3 
108 

69-5 
SS-2 

71-4 

66.7 
54.7 



Lard 



Leaf lard 
Beef tallow 
Cottonseed oil 

Lard and cotton- 
seed oil 

Lard and beef 
tallow 

Lard and cotton- 
seed oil 
Ditto 

Lard, beef tallow, 
and cottonseed 
oil 



Notes on the Above Table. — It will in general be noted that adultera- 
tion of lard with cottonseed oil alone is indicated by an abnormally high 



EDIBLE OILS /IND FATS. 457 

refractometer number, while the presence of tallow will result in an 
abnormally low refraction. But both adulterants may be present and 
a normal refraction result. In such a case the positive detection of one 
of them, such as the cottonseed oil by the Bechi or Halphen test, will 
indirectly show the presence of the other (tallow), and this indirect proof 
will be confirmed by crystallization. 

Samples A, B, and C give reactions corresponding to normal, pure 
lard. D, E, and F show somewhat high refractometer and iodine 
numbers, but give no direct reaction for cottonseed oil by the Bechi test. 
G, although showing low iodine and refractometer numbers, gives no 
evidence of the presence of tallow by crystallization. In fact, the crj's- 
tals from this sample proved under all circumstances to be most clearly 
typical of pure lard, broad and flat plates with obliquely cut ends. 

This sample was, in fact, pure leaf lard. It is generally true that a 
stiff, strictly pure leaf lard, wliich both by its consistency and by its low 
iodine and refractometer numbers might suggest the presence of beef fat, 
shows on crystallization much more definitely characteristic lard stearin 
than does a whole-hog lard, whose iodine and refractometer numbers 
are more nearly the normal standard. 

In distinction from such leaf lard, a sample which may have a similar 
consistency and iodine and refractometer numbers, but which is composed 
of a whole-hog lard of a comparatively high iodine number, together 
with beef fat, gives unmistakable proof of its adulteration by its crystal- 
lization. 

REFERENCES ON EDIBLE OILS AND FATS. 

Andes, L. E. Animal Fats and Oils. 

Vegetable Fats and Oils. London, 1897. 

Benedikt R. Analyse der Fette und Wachsarten. Berlin, 1892. 

Beauvisage, G. Les Matieres Gras. Paris, 1891. 

BocKAiRY, L. Huiles Comestibles. Analyse des Matiferes AHmentaires (Girard et 

Duprd), p. 401. Paris, 1894. 
Bornemann, G. Die Fetten Oele des Pflanzen und Thierreiches. Weimar, 1889. 
Brannt, W. T. Animal and Vegetable Fats and Oils. Phila., 1888. 
Cannizzaro, S., and Fabeis, G. Reliability of Tests for Determining the Purity of 

Olive Oil. Rome, 1891. 
Gill, A. A Short Handbook of Oil Analysis. Phila., 1900. 
Hehner, O., and Mitchell, C. A. On the Determination of Stearic Acid in Fats. 

Analyst, 21, 316. 
Hopkins, E. H. The Oil Chemists' Handbook. New York, 1901. 
Hunt, F. W. A Comparison of Methods used to Determine the Iodine Values of Oils. 

Jour. Soc. Chem. Ind., 1902, 454. 



458 FOOD INSPECTION AND ANALYSIS. 

Lewkowitsch, J. Chemical Analysis of Oils, Fats, and Waxes. London, 1898. 

Laboratory Companion to Fats and Oils Industries. London, 1901. 

LiCHTENBERG, C. Die Fettwaaren und fatten Oele. Weimar, 1880. 

Lythgoe, H. C. Readings on the Zeiss Butyro-refractometer of Edible Oils and Fats. 

Technology Quarterly, 16, 1903, p. 222. 
M.ACFARLANE, T. OHve Oil. Can. Inl. Rev. Dept. Bui. 67. 
Rae & Co. Prima Arborum. The Ohve Tree and its Fruit. New York, 1887. 
ScHADLER, C. Die Untersuchung der Fette, Oele, Wachsarten, etc. Leipzig, 1889. 

Die Technologic der Fette und Oele des Pflanzen und Thierreichs. Leipzig, 1892. 

Thalmann, F. Die Fette und Oele. Leipzig, 1881. 

ToLMAN, L. M. Edible Oils and Fats. U. S. Dept. of Agric, Bur. of Chem., Bui. 65, 

p. 20. 
ToLMAN, L. M., and Mxjnson, L. S. Use of the Bechi Test in Ohve Oils. Jour. Am. 

Chem. Soc, 24, 1902, 397. 

Refractive Indices of Salad Oils. Jour. Am. Chem. Soc, 24, 1902, 754. 

— ■ — - Iodine Absorption of Oils and Fats. Jour. Am. Chem. Soc, 1903, 244. 

Olive Oil and its Substitutes. U. S. Dept. of Agric, Bur. of Chem., Bui. 77. 

Villon, A. M. Les Corps Gras. Paris, 1890. 

VuLTE, H. T., and Gibson, H. W. Nature and Properties of Corn Oil. Jour. Am. 
Chem. Soc, 23, i. 

Wright, A. C. Analysis of Oils and Allied Substances. New York, 1903. 

Wkight, C. R. a. Animal and Vegetable Fixed Oils, Fats, Butters, and Waxes. Lon- 
don, 1894. 

California Exp. Sta. Buls. 104, 123, 129, 137, et al. on Cahforaia Olives and Olive 

Oils. 
CaUfomia Exp. Sta. An. Reports, 1892 et seq. 
Connecticut E.xp. Sta. An. Report, 1897, p. 44. 



REFERENCES ON BUTTER. 

Alvord, H. E. Composition and Characteristics of Butter. Penn. Dept. of Agric. 

An. Rep., 1898, p. 558. 
BocKAiRY, L. Beurre, Analyse des Matiferes Alimentaires (Girard et Dupre), p. 351. 

Paris, 1894. 
Brackett, E. G. Healthfulness of Oleomargarine as an Article of Food. Mass. State 

Board of Health An. Rep., 1887, p. 248. 
Browne, C. A., Jr. A Contribution to the Chemistry of Butter Fat. Jour. Am. 

Chem. Soc, 21, 1899, 612, 807, 975. 
Cochran, C. B. Butter and Butter Adulterants. Jour. Frankl. Inst., 147, 1899, 85. 

Butter and Butter Adulterants. Penn. Dept. of Agric. An. Rep., 1898, p. 616. 

— — Detection of Foreign Fats in Butter. Jour. Am. Chem. Soc, 19, p. 796. 
Cornwall, H. B. Examination of Butter Colors. Chem. News, 55, p. 49. 
Geissler, J. F. A Delicate Test for Color in Butter. Jour. Am. Chem. Soc, 20, 

p. no. 



EDIBLE OILS AND FATS. 459 

Genth, F. a. The Necessity for a Butter Standard. Perm Dept. of Agric. An. Rep., 
1897. p. 549- 

GiRARD et Brevans. Le Margarin et le Beurre Artificiel. Paris, 1889. 

Hehner, O., and Angell, A. Butter, its Analysis and Adulteration. London, 1877. 

Hess, W. H., and Doolittle, R. E. Methods for the Detection of Process or Reno- 
vated Butter. Jour. Am. Chem. Soc, 22, 150. 

Hummel, J. A. Examination of Brown and Taylor's Official Method of Identifying 
Butter. Jour. Am. Chem. Soc, 22, 1900, 327, 703. 

Lang, V. Fabrikation von Kunstbutter. Leipzig, 1885. 

Low, A. W. Testing for a Yellow Azo-Color in Fats. Jour. Am. Chem. Soc, 20 
(1898), p. 889. 

Macfarlane, T. Butter. Can. Inl. Rev. Dept. Bui. 16. 

Martin, E. W. Detection of Artificial Coloring Matter in Butter, Oleomargarine, 
etc. Analyst, 12, 1887, p. 70. 

Moore, R. W. A Test for Carrot Color in Butter. Analyst, 11, 1886, 163. 

VON Ryn, J. J. L. Composition of Dutch Butter. London, 1902. 

DE SCHWEINITZ and Emery. Use of the Calorimeter in Detecting Adulterations of 
Butter. Jour. Am. Chem. Soc, 18, p. 174. 

Sell, E. Ueber Kunstbutter, ihre Herstellung, etc. Berlin, 1886. 

Stebbins, J. H. On the Reichert Figure of Butter. 

Zane, a. J. General Analyse des Beurres. Paris, 1892. 

Farmer's Bulletin 12. Nostrums for Increasing the Yield of Butter. 

" " 57. Butter Making on the Farm. 

" " 92. Pasteurization in Butter Making. 

" " 131. Household Tests for the Detection of Oleomargarine and 

Renovated Butter. 
Minnesota Exp. Station Bui. 74. Digestibility and Food Value of Butter. 
New York Exp. Sta. (Ithaca), Bui. 118. Butter Increasers. 
North Carolina Exp. Sta. Bui. 166. Butter, its Composition, Artificial Imitation, and 

Adulterants. 
Storrs Conn. Exp. Sta. nth An. Rep., page 85. Bacteriology in Butter Making. 

REFERENCES ON LARD. 

Cochran, C. B. Detection of Foreign Fats in Lard and Butter. 

CONROY, M. Lard, its Adulteration with Cottonseed Oil and Detection Thereof. Ana- 
lyst, 13, 203. 

Gladding, T. S. Examination of Lard for Adulteration. Analyst, 14, 32. 

Microscopic Detection of Beef Fat in Lard. Jour. Am. Chem. Soc, 18, 189. 

Hehner, O. On Belfield's Test for Beef Stearin in Lard. Analyst, 27, 247. 

Macfarlane, T. Lard. Canadian Inl. Rev. Dept. Bui. 7. 

Stock, W. F. K. On the Estimation of Beef Fat in Lard. Analyst, 19, 2. 

Tennile, G. F. Determination of Solid Fats in Compound Lard'. Jour. Am. Chem. 
Soc, 19, 51. 

Wesson, D. Examination of Lard for Impurities. Jour. Am. Chem. Soc, 17, 723. 



46o FOOD INSPECTION /4ND yiN^ LYSIS. 

Wiley, H. W. Quantitative Estimation of Adulterants in Lard Analyst, 14, 1889, 

P- 73- 
Lard and Lard Adulterations. U. S. Dept. of Agric, Div. of Chem., Bui. 13, 

part 4. 
WiRTHLE, F. Detection of Cottonseed Stearin in Lard. Analyst, 27, 247. 

Conn. Exp. Sta. An. Rep., 1896, p. 128 

Mass. State Board of Health An. Rep., 1895, p. 668. 



CHAPTER XIII. 
SUGAR AND SACCHARINE PRODUCTS. 

Nature and Classification of Sugars. — Of all classes of food mate- 
rials the sugars from their great solubility are the most readily available, 
and on this account are very valuable as nutrients. As in the natural 
processes of digestion the starches and more difficuUly digestible of the 
carbohydrates are converted into sugar and thus rendered assimilable, 
so by processes quite analogous to those that take place in the alimentary 
tract, the chemist converts these same carbohydrates into sugar as an 
end-point for purposes of definite determination. 

The sugars are characterized by their sweet taste, their ready solu- 
bility in water, their power to rotate the plane of polarized light, and 
their insolubility in ether and absolute alcohol. 

The sugars occurring commonly in food naturally divide themselves 
into two groups: First, the Saccharoses, or cane sugar group, having 
the composition CijHjjOu, of which the most prominent members are 
sucrose, maltose, and lactose; and, second, the Glucoses, or grape sugar 
group, expressed by the formula CeH^jOe, which includes dextrose, levulose. 
and galactose, besides other less common sugars. 

The members of both groups are intimately related. Thus by the 
ordinary process of so-called inversion sucrose, or cane sugar, belonging to 
group I, is converted by the action of heat and dilute acid into two sugars, 
dextrose and levulose, which are members of group 2, in accordance 
■with the following reaction: 



CioHjjOii-t-HjO =CsH,206+C6H^,Oa• 
Cane sugar Dextrose Levulose 



The same formula expresses also the result that takes place when 
lactose, or milk sugar, is heated with dilute acids, breaking up into dextrose 

and galactose. 

461 



462 



FOOD INSPECTION AND ANALYSIS. 



Occurrence. — Sugars occur in roots, grasses, stems of plants, trunks 
of trees, leaves, and fruits, usually in the form of cane sugar, or sucrose, 
and of invert sugar (dextrose and levulose) mixed in varying propor- 
tions. 

The following table from Buignet * shows the kind and amount of 
sugars occurring in some of the common fruits : 



Apricots 

Pineapples 

English cherries. . 

Lemons 

Figs 

Strawberries 

Raspberries 

Gooseberries . 

Oranges 

Peaches (green). . 
Pears (Madeleine) 
Apples 

Prunes 

Grapes (hothouse) 
' ' green 



Cane Sugar. 



6.04 

"■33 
.00 

.41 
.00 

6-33 



4.22 
.92 

-36 
5.28 
2.iq 

5-24 
.00 
.00 



Reducing 
Stigar. 



■74 



2. 

i.9» 

10.00 

1.06 

"•55 
4.98 
5.22 
6.40 
4-36 
1.07 
8.42 
8.72 
5-45 
2-43 

17.26 
1.60 



Acid. 



1.864 

•547 
.661 

4.706 
■°S7 
-55° 

1.380 

1-574 

.448 

3.900 

■115 
1. 148 

•633 
1.288 

-345 
2.48s 



CANE SUGAR, OR SUCROSE. 

Nature and Occurrence. — This, the most common of all the sugars, 
is nearly always understood by the unqualified term of sugar. It crys- 
tallizes in monoclinic prisms. Its specific gravity is 1.595. Its mehing- 
point is about 160° C. Its specific rotary power [a]p in solutions having 
a concentration of from 10 to 20 grams in 100 cc. is, according to Tollens, 
66.48°. Sucrose is extremely soluble in water, which, when cold, will 
hold in solution twice its weight of the sugar. 

Cane sugar is ordinarily derived from four sources — the sugar beet, 
the sugar cane, the maple tree, and the sorghum plant. The first two 
sources supply the principal output of commercial cane sugar, about 
two-thirds of the sugar on the market being furnished, according to 
Wiley, by the sugar beet and one-third by the sugar cane. It should be 
understood that the product sucrose, or cane sugar, is chemically the same 
whether derived from either of the above sources and thoroughly refined. 

U. S. Standard Sugar is white sugar containing at least 99.5% of 
sucrose. 

* Ann. Chim. Phys., 59, 233. 



SUGAR AND SACCHARINE PRODUCTS. 



463 



The Sugar Cane (Saccharum officinarum) is cultivated principally in 
Louisiana and other southern states, in Cuba and the West Indies, and 
in the Hawaiian Islands. Its growth and cultivation form an industry 
in nearly all tropical countries. 

Allen * has compiled the following table showing the composition 
of the juice of the sugar cane from different localities: 



Locality and Kind 
of Cane. 


Water. 


Sugar. 


Woody 
Fiber. 


Salts. 


Authority. 


Martinique 

Guadaloupe 


72.1 
72.0 
77.0 

65-9 
69.0 

76-73 
76.08 


18.0 
17.8 
12.0 

17-7 
20.0 

13-39 
14.28 


9-9 
9-8 

II .0 

16.4 
10. 

9-07 
8.87 


0.4 
I.O 

-39 

-35 


Peligot 
Dupuy 


Cuba 






leery 

Avequin 

Avequin 


Ribbon cane 

Tahiti 





The composition of raw cane sugar ash according to Monier is as 
follows : 

RAW CANE SUGAR ASH. 

Carbonate of calcium 49.00 

" " potassium 16.50 

Sodium and potassium sulphate 16.00 

Sodium chloride 9 .00 

Silica and alumina 9-5° 



100.00 



Manufacture of Cane Sugar. — The process of manufacturing raw 
sugar from sugar cane is briefly as follows: The juice is tirst e.xtracted 
from the canes by crushing in roll mills and is freed from nitrogenous 
bodies, organic acids, etc., by the process of defecation, which consists 
in heating to coagulate the albumin, and nearly neutralizing with milk 
of lime, the impurities being removed as a scum. The juice is then 
subjected to evaporation and crj'stallization, the raw, or muscovado sugar, 
which contains from 87 to 91 per cent of sucrose, being separated from 
the molasses, which is the mother licjuor, by draining or by centrifugal. 

Some of the best grade of muscovado, or raw sugar, is used as ' ' brown 
sugar" without further refining, and much of the molasses is used as a 
table syrup and for cooking, while the lower grades of molasses are used 
in the manufacture of ram. 



' Com. Org. Analysis, i, p. 315. 



464 



FOOD INSPECTION AND A N/1 LYSIS. 



The following table from Thorpe * shows the average composition 
of raw and refined sugar: 



Cane 
Sugar. 



Glucose^ 



Water. 



Organic 

Matter. 



Ash. 



RAW SUGAR. 

Good centrifugal 

Poor centrifugal 

Good muscovado 

Poor muscovado 

Molasses sugar 

Jaggary sugar , 

Manilla sugar , 

Beet sugar, ist 

Beet sugar, 2d , 



REFINED SUGAR. 

Granulated sugar 

White coffee sugar 

Yellow X C sugar 

Yellow sugar 

Barrel sugar 



96. 
92. 
91. 
82. 
85. 

75- 
87. 

95- 
91. 



99-8 
91 .0 
87.0 
82.0 
40.0 



°-75 
2.50 
2.25 
7.00 
3.00 
11.00 

5-5° 
0.00 
0.25 



0.20 
2.40 
4-5° 
7-5° 
25.00 



1.50 
3.00 
5.00 
6.00 
5.00 
8.00 
4.00 
2.00 
3.00 



0.00 

5-50 

6.00 

6.00 

20.00 



0.85 

1-75 
1. 10 

3-50 
5.00 
4.00 
2.25 
1-75 
3-25 

0.00 
0.80 
1.50 
2.50 
10.00 



0.40 

0-75 
0.65 
1.50 
2.00 
2.00 
1-25 
1-25 
2.50 

0.00 
0.30 
1. 00 
2.00 
S.oo 



' The term " ' glucose ' 
optically active. 



includes sugars which reduce Fehling's solution, but are not necessarily 



The following minimum and maximum figures are taken from analyses 
made by Babington f of twenty-two samples of brown sugar and thirty- 
one samples of molasses. 



BROWN SUGAR. 

Direct polarization 84 to 87 

Invert " -27 " -29 

Sucrose by Clerget 83 . 5 "' 91.5 

Reducing sugar 3 " 6 

Moisture 3-5" 6 

Ash 0.8" 3.0 

MOLASSES. 

Direct polarization 30 to 50 

Invert " -10 " -21 

Sucrose by Clerget 32 " 52 

Reducing sugar 13 " 24 

Moisture 29 " 32 

Ash 0.5" 4 

* Outlines of Industrial Chem., p. 383. 
t Can. Inl. Rev. Dept. Bui. 25. 



SUG/IR AND SACCHARINE PRODUCTS. 



465 



The Sugar Beet {Beta vulgaris) is grown chiefly in France and Ger- 
many, and to a lesser extent in Holland and England. The successful 
growth of the sugar beet in the United States is confined mainly to Cali- 
fornia, Utah, and Nebraska, and the entire output of beet sugar in this 
country is comparatively small. 

According to R. Hoffmann, sugar beets have about the following 
composition, three types being selected — first, those poor in sugar; second, 
those having a medium sugar content, and third, those rich in sugar: 



COMPOSITION OF THE SUGAR BEET. 



First Type. 


■ Second Type. 


Third Type 


8g.20 


83.20 


75 • 20 


4.00 


9.42 


15.00 


1. 00 


1.64 


2.20 


4.13 


3-34 


4.2,3 


1. 01 


1.50 


2.07 


0.66 


0.90 


1.30 


100.00 


100.00 


100.00 



Water 

Sugar 

Nitrogenous compounds 

Non-nitrogenous compounds: 

Soluble 

Insoluble (cellulose) 

Ash 



The following is the mean composition of ten samples of California 
sugar beet : * 

Per cent juice extracted 61 .38 

Specific gravity i .062 to i .075 

Per cent of reducing sugar o.gi 

Per cent of sucrose 14-38 

Total solids calculated 16.58 

Total solids weighed 1 7 . 20 

Per cent of ash o . 994 

The composition of beet sugar ash according to Monier is as follows: 

RAW BEET SUGAR ASH. 

Carbonates of potassium and sodium 82 . 20 

Carbonate of calcium 6.70 

Potassium and sodium sulphate and sodium chloride. ... 11 .10 

100.00 

Manufacture of Beet Sugar. — In making raw sugar from sugar beets 
the latter arc first washed and sliced by machinery and the juice extracted 

* U. S. Dept. of Agric, Div. of Chem., Bui. 27, p. 202. 



466 FOOD INSPECTION /iND /IN A LYSIS. 

by difjudon or digestion with warm water. The juice is then clarified 
or defecated in much the same manner as that from the sugar cane, after 
which it is usually bleached with sulphur dioxide. 

The subsequent evaporation and crystallization are carried out usu- 
ally in vacuum pans, and the sugar separated out by centrifugals. 

Beet sugar molasses is unfit for food, due to the presence of nitroge- 
nous bodies, which give it a very unpleasant taste and smell. 

Process of Refining. — In refining raw sugar, a syrup is made, which 
is subjected to centrifuging and further defecation, using lime, clay, 
liquid blood, calcium acid phosphate, and other substances as clarifiers. 
The juices are then filtered, first through cloth bags and then through 
bone char, after which they are evaporated and allowed to crystallize, the 
resulting granulated sugar being separated, as in the case of raw sugar, 
by centrifugal machines. 

Granulated Sugar of cornmerce is without doubt the purest food product 
on the market, being generally 99.8% sucrose. It is usually treated with 
an extremely weak solution of ultramarine to counteract the natural 
yellow color. 

The syrup from which the granulated sugar is separated forms the 
"golden," or "drip," syrup used on the table. Its typical composition 
is as follows: Sucrose, 40%; reducing sugars, 25%; water, 20%; organic 
matter, 10%; ash, 5%. 

The dry sugars, whether white or brown, are rarely subjected to 
adulteration. 

Maple Sap. — The sap of the maple tree, Acer saccharinum, or Acer 
harhatiiin, furnishes a sugar considerably prized for its peculiar flavor. 
The maple sugar industry is largely confined to the northeastern states 
and to Canada, and the maple sugar season is generally limited to six 
weeks or two months in the spring. 

The following are minimum and maximum figures from the analyses 
of five samples of maple sap made in Massachusetts: 

Specific gravity i -ooy to i .015 

Sucrose 0.769'" 2.777 

Reducing sugar " 0.012 

The ash of maple sap varies from 0.5 to i per cent. Albuminoids 
are present in amount varj-ing from 0.008 to 0.03 per cent. 

Maple Sugar and Syrup are made by simply boiling down the sap 
to the proper consistency, usually in open pans, and removing the scum 



SUGAR AND SACCHARINE PRODUCTS. 



467 



with great care, since this contains nitrogenous matters that would cause 
fermentation in the finished product. Pure cane sugar is never com- 
mercially produced from the maple sap, since the refining process would 
deprive it of the flavor which gives to maple sugar the chief value. 

McGill gives the following as the average analyses of six samples 
of maple syrup of known purity: 





Saccharim- 
eter Invert. 


Cane Sugar 
by Clerget. 


By Copper. 


Ash. 


Water. 




eter Direct. 


Reducing 

Sugar. 


Cane Sugar. 


SoKds. 


+ 62.2 


— 21.2 


62.4 


.42 


63-36 


•53 


35-7° 


64.30 



The following is a summary of the analyses of twenty samples of 
maple sugar : * 

Sucrose 71.80 to 86.89% 

Reducing sugar Trace" 12.19% 

Water 6.77 " 11.57% 

Ash 0.31" 1.50% 

Methods for the analysis of maple sugar are identical with those for 
raw, or brown, sugar. 

Adulleralion 0] Maple Sugar and Syrup. — The chief aduUerants of 
maple sugar arc brown, or molasses sugar, and white, or refined sugar, 
the latter being often used in mixture with burnt or inferior maple stock, 
which itself would be abnormally dark in color and of a rank taste. 
Maple syrup is commonly adulterated with golden, or drip syrup, wi:h 
commercial glucose, with molasses, and with refined sugar. 

The ash of pure maple syrup, according to Sharpies, should not be 
less than 0.35 or 0.40 per cent, a lower ash indicating the admi.xture of 
refined cane sugar. On the other hand, the addition of molasses, or 
brown sugar stock would tend to raise the ash far above the average for 
pure maple, as well as to increase the reducing sugars. A high reducing 
sugar, say over 5%,, while suspicious, should not be assumed as conclusive 
evidence in itself of molasses sugar, since old and inferior samples of 
maple sugar and syrup are sometimes found with reducing sugar abnor- 
mally high. It is frequently possible to identify brown, or molasses, 
sugar, especially when it forms the larger portion of the alleged maple 
sugar or syrup by the physical sense of taste. When the perfectly charac- 

* U. S. Dept. of .Agric, Div. of Chem., Bui. 5, p. ig8. 



468 FOOD INSPECTION AND ANALYSIS. 

teristic taste of brown, or molasses sugar, or of " drip syrup," so far 
predominates over the maple flavor as to be unmistakable, especially in 
cases where the maple flavor is entirely lacking, one need have little 
hesitation in condemning the product.* See also Appendix, p. 767. 

Sorghum {Andropogon sorghum, variety saccharatus) has for many 
years been growm quite extensively in the southern and western states, 
and used as a source of syrup, but only in recent years has it been found 
practicable to produce crystallized cane sugar from it on account of the 
presence of starch, uncrystallizable sugar, etc. 

Much experimental work has been done of late along this line by the 
U. S. Department of Agriculture. The sorghum plant is as yet, however, 
a very small factor in the production of cane sugar, though much progress 
is being made. 

The composition of the juice of the sorghum plant is shown by the 
following results of analyses of eleven varieties made by Hardin: f 

Total solids 15-97 to 18.71 

Specific gravity i .0656 " i .0775 

Solids not sugar 5.02 " 10.63 

Cane sugar 2.81 " 8.01 

Reducing sugars 3.87 " 7.55 

Some varieties of sorghum juice have been known to contain 15 or 
even 17 per cent of sucrose. 

In making syrup from sorghum, the ripe canes are crushed, the juice 
is heated with milk of lime, and the scum removed. The juice is then 
concentrated usually in open pans to the required consistency. 

GRAPE SUGAR, OR DEXTROSE. 

Dextrose (CoHi^Oe+HjO), otherwfse known as starch sugar, occurs 
in honey with levulose, and in fruits with both levulose and cane sugar. 
It is produced by the action of dilute acids or of certain ferments on starch, 
dextrin, or cane sugar. Grapes contain about 15% of dextrose. Anhy- 
drous dextrose is soluble in 1.2 parts of cold water. It is soluble in alcohol, 
but less so than cane sugar. It is much less sweet than cane sugar. 

* The sense of taste, if properly cultivated, and with its limitations recognized, should be 
entitled to as much consideration as the other senses in forming an opinion. Taste and smell 
are often vers' useful factors in detecting adulterants, but should of course be used with dis- 
cretion. 

t U. S. Dept. of Agric, Div. of Chem., Bui. 37, p. 75. 



SUGAR AND SACCHARINE PRODUCTS. 469 

The specific rotary power of dextrose is 

[a]D=52-3. [a]; = s8. 

A normal solution of dextrose on the Soleil-Ventzke scale polarizes at 
78.6°. For the commercial preparation of dextrose see p. 471. 

U. S. Standards for Various Sugars. — Standard 70 sugar, or brewers' 
sugar, is hydrous starch sugar containing not less than 70% of dextrose, 
and not more than 0.8% of ash. 

Standard 80 sugar, climax, or acme sugar, is hydrous starch sugar 
containing not less than 8o9^i of dextrose,, and not more than 1.5% of ash. 

Standard anhydrous grape sugar is anhydrous grape sugar contain- 
ing not less than 95% of dextrose without water of crystallization, and 
not more than 0.8% of ash. 

The ash of these standard products consists almost entirely of chlorides 
and sulphates of lime and soda. 

LEVULOSE. 

Levulose is of importance in foods only as the product of inversion 
of cane sugar. It is prepared by the action of dilute acids on inulin. 
Normally it is in the form of a syrup, being with difficulty cr\-stallized, 
but with extreme care pure anhydrous levulose can be obtained. Dia- 
betene is a commercial form of dry levulose. Levulose is formed with 
dextrose in the inversion of cane sugar (p. 461), and with dextrose occurs 
in honey and in many fruits. The specific rotary power of levulose 
varies with the temperature. At 15° C. [«]£>= —98.8°, decreasing by 
0.6385° for each degree increase in temperature. Its left-handed reading 
on the Ventzke sugar scale at 15° C. is equivalent to 148.6°. Levulose 
is sweeter than de.xtrose. Its reducing power on Fehling's solution is 
assumed to be the same as that of dextrose. 

MALT SUGAR, OR MALTOSE. 

Maltose (CijH^jOji-f HjO) is of little importance from the standpoint 
of the food analyst, excepting as an ingredient of commercial glucose, 
and as being the sugar produced by the action of ptyaHne, the ferment 
of the saliva on the starch of food in the ordinary process of digestion. 
When gelatinized starch is subjected to treatment with malt extract at 
55° to 60° C, it is converted into dextrin and maltose as follows: 

C,sH3„0,5+ H3O = CeH.oOs-f C,M,fi,,. 

Starch Dextrin Maltose 



470 FOOD INSPECTION AND ANALYSIS. 

In its commercial preparation maltose is separated from dextrin by 
crystallization in alcohol. By the action of weak acids and heat bofh 
dextrin and maltose are further converted into dextrose. 

iSIaltose usually crystallizes in minute needles, and its molecule of 
water is expelled at iio°C. It is somewhat less soluble in water than 
dextrose. It is slightly soluble in alcohol, though less than sucrose. So- 
lutions of maltose possess the property of birotation; i.e., when freshly 
prepared they do not at once assume their true optical activity. The 
rotation of a freshly prepared solution of maltose increases on standing, 
requiring several hours to reach its maximum. The specific rotary 
power, according to O'Sullivan, of anhydrous maltose is [a]o= 139.2, 
[a]y= 154.5. For hydrated maltose [a]p would thus be 132.2. 

A normal solution of maltose on the Soleil-Ventzke scale should po- 
larize at 198.8°. 

DEXTRIN. COMMERCIAL GLUCOSE. 

DEXTRIN, (CeHioOj),, possesses more the nature of a gum than of a 
sugar, and is sometimes called British gum. It is said to occur naturally 
in the sap of various plants, but this is not definitely assured. 

It undoubtedly occurs in beer and in bread crust, and is one of the 
constituents of commercial glucose. Like starch, it is convertible by 
hydrolysis with acid into dextrose. By treatment of starch with malt 
extract or diastase, starch is converted into dextrin and maltose, these 
two bodies being separated, in the commercial preparations of dextrin, 
by repeated treatment with alcohol. 

Dextrin is an uncrystallized, colorless, tasteless body, capable of 
being pulverized. It is readily soluble in water, slightly soluble in dilute 
alcohol, but insoluble in alcohol of 60% or stronger. It is not colored 
by iodine, and exercises no reducing action on alkaline copper solution. 
Its specific rotary power is [a]o=2oo, [a] =222. 

Commercial Glucose, otherwise known as mixing syrup, crystal syrup, 
and slarch, or corn syrup, is a heavy, mildly sweet, colorless, semi-tluid 
substance, having a gravity of 40° to 45° Baume. It is largely used as 
an adulterant of maple syrup, molasses, honey, drip syrup, and jellies 
and jams, and as an ingredient of confectionery. 

In France and Germany it is made from potato starch, but in the United 
States mainly from corn. The starch, being first extracted from the 
corn, is boiled with dilute acid (usually sulphuric), after which the acid 
is neutralized with marble dust, precipitating out calcium sulphate, the 



SUGAR AND SACCHARINE PRODUCTS. 471 

juice is filtered through bone black, and finally concentrated by evapora- 
tion, the degree of conversion and of concentration depending on whether 
the liquid glucose or the solid dextrose is wanted for the final product. 
The end product obtained by complete conversion is the dry commercial 
grape sugar, or dextrose, which is purified by repeated crystallization. 

Commercial glucose is a mixture of dextrin, maltose, and de.xtrose 
of the following varying composition: 

Dextrin 29.8% to 45-3% 

Maltose 4.6% "19.3% 

Dextrose 34-3% "36-5% 

Ash 0.32% " 0.52% 

Water 14.2% "17.2% 

Calcium sulphate is usually found in the ash. 

Solid commercial grape sugar, or dextrose, has the following com- 
position: 

De.xtrin 0% 9 . i"/o 

Maltose ' 0% 1.8% 

Dextrose 72% 99-4% 

Ash 0.3% 0.75% 

Water 0.6% 17.5% 

U. S. Standard glucose, mixing glucose, or confectioners' glucose, is color- 
less glucose, var)'ing in density between 41° and 45° Baume, at a tempera- 
ture of 100° F. (37.7° C). It conforms in density, within these limits, to 
the degree Baume it is claimed to show, and for a density of 41° Baume 
contains not more than 21% of water, and for a density of 45° not more 
than 14%. It contains on a basis of 41° Baume not more than 1% of 
ash, consisting cliiefly of chlorides and sulphates of lime and soda. 

Healthfulness of Glucose. — The analyst alleging commercial glucose 
as an adulterant is frequently asked in court as to its healthfulness, so 
that the following conclusions of a committee appointed some years ago 
by the National Academy of Sciences to ascertain among other things 
whether there is any danger attending the use of this product in food are 
in point: "First, that the manufacture of sugar from starch is a long- 
established industry, scientifically valuable and commercially important; 
second, that the processes which it employs at the present time are unob- 
jectionable in their character and leave the product uncontaminated; 
third, that the starch sugar thus made and sent into commerce is of excep- 



472 FOOD INSPECTION AND ANALYSIS. 

tional purity and uniformity of composition and contains no injurious 
substances; and fourth, that though having at best only about two- 
thirds the sweetening power of cane sugar, yet starch sugar is in no way 
inferior in heaUlifulness, there being no evidence before the committee 
that maize starch sugar, either in its normal condition or fermented, has 
any deleterious effect upon the system, even when taken in large quan- 
tities." 

MILK SUGAR, OR LACTOSE. 

Lactose (CioHjjOn+HjO) is prepared commercially from skim- 
milk by coagulating with rennet and digesting the whey with chalk and 
aluminum hydroxide. The insoluble matter is filtered out, and the 
filtrate is concentrated in vacuo to a syrup, wliich, on standing, yields 
crystals of lactose. The product is purified by repealed crystallization. 

Lactose ordinarily crystallizes in rhombic, hemihedral crystals. Its 
specific gravity is 1.525. Its water of crystallization is lost by drying at 
130° C. It is soluble in 6 parts of cold water, and in 2i or less of boiling 
water. It is insoluble in absolute alcohol and ether. It has a very slightly 
sweet taste. 

The .specific rotary power of milk sugar, after remaining in solution 
long enough to overcome its birotation, is 

[a]/> = 52-5- 

In the ordinary souring of milk the lactose becomes converted into 
lactic acid. 

On heating lactose with dilute acids it undergoes inversion, forming 
dextrose and galactose in accordance with the formula given on p. 461, 
illustrating the inversion of cane sugar. 

Milk sugar is of considerable importance by reason of the large amount 
used of late in the preparation of modified milk for infant feeding. 

Grape sugar and cane sugar are to be looked for as adulterants of 
milk sugar. 

The purity of milk sugar is best established by titrating against Feh- 
ling's solution, 10 cc. of which are equivalent to 0.067 gram of lactose. 

RAFFINOSE. 

Raffinose, CijHjjOieSHoO, is a sugar belonging neither to the saccha- 
rose nor the glucose group, but to the so-called saccharoid group, the other 
members of which do not occur in foods. 



SUGAR AND SACCHARINE PRODUCTS. 



473 



Raffinose occurs in beet root molasses to the extent of fron 3 to 4 
per cent. It is a crystalline, slightly sweet substance, soluble in water 
and slightly soluble in alcohol. It does not reduce Fehling's solution, 
but readily undergoes fermentation. On inversion it splits up into 
levadose and mclibiose (Ci^HjjOn). 

The melting-point of raffinose is 118° to 119° C. Its specific rotary 
power [«]£!= + 104.5 ^t 3, temperature of 20° C. 

THE POLARISCOPE AND SACCHARIMETRY. 

A full discussion of the principles of polarized light and even a detailed 
description of their application to the polariscope will not be given here, 
but the reader who wishes full information along this line is referred to 
the various text-books, and especially to those of Tucker, Spencer, and 
Landolt ,* in which various forms of polariscopes are described and their 
underlying principles discussed. 

The Soleil-Ventzke Saccharimeter is the one most commonly used 
in this country, being adopted as the standard for all United States govern- 
ment work. Fig. 99 shows this instrument, known as the half -shadow 




I [Daf □ 



Fig. 99. — Single-wedge Saccharimeter. 

apparatus, in its simplest form with a single movable wedge in its com- 
pensating system. 

An excellent light for work with this instrument is that furnished by 
the Welsbach burner, a convenient form of lamp being shown in Fig. no, 
in which the burner is inclosed in a sheet-metal chimney of suitable con- 
struction. An argand, gas, or kerosene burner may however be used, 



* See references, p. 522. 



474 FOOD INSPECTION AND ANALYSIS. 

and in a late form of Schmidt and Haensch instrument, Fig. loo, a 
specially constructed incandescent electric lamp is supplied. 

The Single-wedge Saccharimeter. — The following description of the 
saccharimeter and directions for its use are from the revised regulations 
of the U. S. Internal Revenue Department. The tube N, Fig. 99, con- 
tains the illuminating system of lenses and is placed next to the lamp; 
the polarizing prism is at O and the analyzing prism at H. The quartz 
wedge compensating system is contained in the portions of the tube marked 
FEG and is controlled by the milled head M. The tube / carries a small 
telescope, through which the field of the instrument is viewed, and just 
above is the reading-tube K, which is provided with a mirror and magnify- 
ing lens for reading the scale. 

The tube containing the sugar solution is shown in position in the 
trough between the two ends of the instrument. In using the instrument 
the lamp is placed at a distance of at least 200 mm. from the polarizing 
end; the observer seats himself at the opposite end in such a manner 
as to bring his eye in line with the tube J. The telescope is moved in or 
out until the proper focus is secured to give a clearly defined image, 
when the field of the instrument will appear as a round, luminous 
disk, divided into halves by a vertical line passing through its center, 
and darker on one half of the disk than on the other, when the com- 
pensating quartz wedge is displaced from the neutral position. If the 
observer, still looking through the telescope, will now grasp the milled 
head M and rotate it first one way and then the other, he will find 
that the appearance of the field changes, and at a certain point the 
dark half becomes light and the light half dark. By rotating the milled 
head delicately backward and forward over this point he will be able to 
find the exact position of the quartz wedge operated by it, in which the 
field is neutral, or of the same intensity of light on both halves. The 
three different appearances presented by the field are shown in Fig. 103, 
opposite page 477. 

One of the compensating quartz wedges is fixed and the other is 
movable, sliding one way or the other according as the milled head is 
turned, so that for different relative positions of the two wedges a different 
thickness of quartz is interposed in the path of the polarized ray. By 
this means the amount of the rotation which the sugar solution or other 
optically active substance examined exerts upon the light polarized by 
the prism at O may be, as it were, counteracted by varying the relative 
position of the wedges. 



SUGAR AND SACCHARINE PRODUCTS. 



475 



With the milled head set at the point which gives the appearance of 
the middle disk showTi in Fig. 103, the eye of the observer is raised to the 
reading tube K, which is adjusted to secure a plain reading of the divisions, 
and the position of the scale is noted. It will be seen that the scale proper 
is attached to the quartz wedge, which is moved by the milled head; 
and attached to the other quartz wedge is a small scale called a vernier, 
which is fixed, and which serves for the exact determination of the posi- 
tion of the movable scale with reference to* it. On each side of the zero 
line of the vernier a space corresponding to nine divisions of the movable 
scale is divided into ten equal parts. By this device the fractional part 
of a degree indicated by the position of the zero line is ascertained in 




Fig. 100. — Single-wedge SoleilA'entzke Saccharimeter, mounted on Bock Stand and 
provided with Incandescent Electric Lamp. 

tenths; it is only necessary to count from zero until a line is found which 
makes a continuous line with one on the movable scale. 

With the neutral field, as indicated above, the zero of the movable 
scale should correspond closely with the zero of the vernier, unless the 
zero point is out of adjustment. 

Adjusting the Instrument. — If the observer desires to secure an exact 
adjustment of the zero of the scale, or in any case if the latter deviates 
more than one-half of a degree, the zero lines are made to coincide bv 
moving the milled head and securing a neutral field at this point by 



476 FOOD INSPECTION JND ANALYSIS. 

means of the small key which comes with the instrument, and which 
fits a small nipple on the /f//-hand side of F, the fixed quartz wedge of 
the compensating system. This nipple must not be confounded with 
a similar nipple on the r/^/;/-hand side of the analyzing prism H, which 
it fits as well, but which nnisl never be touched, as the adjustment of 
the instrument would be seriously disturbed by moving it. With the 
key on the proper nipple it is turned one way or the other until the 
field is neutral. Unless the deviation of the zero be greater than 0.5° it 
will not be necessary to use the key, but only to note the amount of the 
deviation, and for this purpose the observer must not be content with 
a single setting, but must perform the operation five or six times and take 
the mean of these different readings. If one or more of the readings 
show a deviation of more than 0.2° from the general average they should 
be rejected as incorrect. Between each observation the eye should be 
allowed a moment of rest. 

The Scale usually has no equal divisions on one side of the zero for 
reading right -handed polarization, and 20 equal divisions on the other 
side for left-handed polarization. The scale is an arbitrary one, based 
on the plan that a normal aqueous solution of pure cane sugar (26.048 
grams made up to 100 cc.) will read exactly 100° or divisions to the right 
of the zero. 

The accuracy of various portions of the scale may be verified by 
quartz control plates of varying thickness, usually mounted in tubes, 
the correct polariscopic reading of each of which plates has been accurately 
aetermined, this reading being as a rule marked on the tube. As the 
sugar value of such a quartz plate varies with the temperature, the 
temperature at which the particular reading marked thereon applies is 
usually specified, and in many cases a table giving its exact value at 
different temperatures from 10° to 35° accompanies the plate. 

The Double-wedge Saccharimeter is shown in Fig. loi, the arrangement 
of the optical parts being also shown. 

In this instrument the two sets of wedges employed are of oppo- 
site optical properties, so that extreme accuracy may be arrived at by 
making the readings with both, the inaccuracies of one being compen- 
sated for by the other. Ordinarily in using this form, one movable wedge, 
say the one controlled by the right-hand milled screw head, is set at zero, 
while the reading of the sugar solution or other substance to be polar- 
ized is made with the other movable wedge. 

The Triple-shadow Saccharimeter. — The latest form of saccharimeter 




Fig. 103. — Appearances of the Field in the Half-shadow Saccharimeter. 




Fig. 104. — Appearances of the Field in the Triple-shade Saccharimeter. 

[To face p. 477. 



SUGAR AND SACCHARINE PRODUCTS. 



477 




Fig. ioi. — Double-wedge, Triple-shade Soleil-Ventzke Saccharimeter. 

is the triple-shadow instrument, the construction of the polarizer being 
sho\ATi in Fig. 102. 

In this form the analyzer is the same as in the fore- 
going instruments, but the polarizer consists of one large 
and two small Nicol prisms I, II, and III, the construction 
and arrangement being such that when the compensating 
wedges are at the neutral point, sections i, 2, and 3 of 
the circular field (corresponding respectively to the prisms 
I, II, and III) are evenly lighted, forming a circular 
uniformly colored field, while in any other position of I — 
the wedges section i is dark while 2 and 3 are light or 
vice versa. The accompanying diagram, Fig. 104, shows 
the appearance of the field of this instrument in the three 
positions of the quartz wedge, viz., at the neutral point 
and at both sides thereof. 

The lamp used for illumination should be separated 
from the polariscope on account of the influence of its F^g- i°2. 

heat on the readings. This is best accomplished by 
having the lamp in a separate compartment from the polariscope, so 




47S FOOD INSPECTION AND ANALYSIS. 

that both arc on opposite sides of a partition, an opening in which trans- 
mits the hght. In any event some kind of screen should be interposed 
between the two. Best results are obtained if the room in which the 
observations are made is dark. 

Comparisons of Scales of Various Polariscopes. — Besides the Soleil- 
Ventzke instrument, there are various other forms of polariscope. Among 
the best known of these are Laurent's, Wild's, and Duboscq's, all of 
which are made with scales reading in circular degrees, while in some 
cases modified forms have scales in which, like the Soleil-Ventzke, per- 
centages of sugar are directly read otT. Some instruments are provided 
with double scales reading both circular degrees and percentages of sugar, 
and in certain of the Duboscq instruments additional scales for percent- 
ages of milk sugar and diabetic sugar are provided. 

In the Wild, Duboscq, and Laurent instruments the source of light 
is the sodium llame, yielding what is termed a monochromatic light. 
This is produced by fused sodium chloride passing through a Bunsen 
flame, various mechanical devices being employed for making the light 
continuous. In the Ventzke instrument, as was stated above, the ordinary 
light from a bright gas or oil flame is used. 

For convenience in conversion of readings on one instrument to their 
equivalents on other scales, the following factors can be used: 

1° Ventzke =0.3468° angular rotation D. 

1° angular rotation D =2.8835° Ventzke. 

1° Ventzke =2.6048° Wild (sugar scale). 

1° Wild (sugar scale) =0.3840° Ventzke. 

1° " " " =0.1331° angular rotation O. 

1° angular rotation D =0.7511° Wild (sugar scale) 

1° Laurent (sugar scale) =0.2167° angular rotation D, 

1° angular rotation D =4.6154° Laurent (sugar scale). 

1° Soleil-Duboscq =0.2167° angular rotation D. 

1° " " =0.2450° " " /. 

1° " " =0.620° Soleil-Ventzke. 

1° " " =1.619° Wild. 

1° Soleil-Ventzke =1.608° Soleil-Duboscq. 

1° W'ild =0.618° 

Normal Weights of Sugar for Different Instruments. — The follow- 
ing normal weights (number of grams in loo cc. of water) are those on 
which the scales of the various instruments are based: 

Soleil-Ventzke 26 .048 

Soleil-Duboscq 16.35 

Formerly 16. 19 

Wild, usually 10 or 20 

Laurent 16.19 



SUC/1R AND SACCHARINE PRODUCTS. 479 

Specific Rotary Power. — This is a theoretical term to express a stand- 
ard by which the various optically active substances may be compared, 
and is understood to mean the amount in angular degrees through which 
the plane of polarization of a ray of light of stated wave length is rotated 
by I gram of a given substance dissolved in i cc. of water and forming 
a column i decimeter in length. The actual rotary power of a solution 
varies directly with the length of the column traversed by the light, with 
the concentration of the solution, and with the wave length of light, 
hence the need of a purely theoretical basis for purposes of comparison. 

The specific rotary power is usually expressed as {oc\d or [a];, the 
letters D or /' indicating the character of the light. Thus, D indicates 
the monochromatic light obtained from the sodium flame, named from the 
D line of Fraunhofer in the yellow portion of the spectrum, while j (from 
the French jaune) indicates what is known as the transition tint, the 
rose-purjjle color produced when ordinary white light passes through 
the polarizer and analyzer, placed with their principal sections parallel 
to each other and with a plate of quartz 3.75 mm. thick interposed between 
them.* 

The specific rotary power is determined as follows: 

r 1 r n I^ 

[a]o or [0:], = -^, 

where a = observed angular rotation, 

c = grams of the substance in 100 cc. of the solvent, and 
/ = length of the observation-tube in decimeters; or, in cases where, 
instead of the grams per 100 cc, the percentage composition is known 
(expressed by /> = grams of the substance in 100 grams of the solvent), 

and the specific gravity (expressed by d), then [a]D or [«],= ,. . 

pal 

Birotation. — In polarizing solutions of all the common sugars other 
than sucrose the phenomenon of birotation should be taken into account, 
whereby a change in optical activity is shown by standing. Thus, solu- 
tions of dextrose, Icvulose, and lactose polarize much higlier when freshly 
prepared than after long standing, recjuiring in some instances several 
hours before the lowest or normal ligure is reached. Maltose, on the 
other hand, increases in polarization after standing in solution. By 

* Some confusion is caused by the adoption of the characters D and /, since both would 
naturally seem to indicate yellow light. The so-called transition tint above defined is, how- 
ever, complementary to the mean yellow, or jaune moyen, and it is the complementary color 
and not the yellow itself that is indicated by the character / 



480 FOOD INSPECTION AND ANALYSIS. 

boiling the solution it may be at once brought to its correct reading. The 
desired result may also be accomplished by adding a few drops of ammo- 
nia, either treatment being resorted to before the solution is made up to 
the required volume. 

ANALYSIS OF CANE SUGAR AND ITS PRODUCTS. 

Qualitative Tests for Sucrose. — (a) Polariscopc Test. — The substance 
to be tested, if not already in solution, is dissolved in water, and if the 
solution is not perfectly clear, is clarified by the ?ddition of alumina 
cream or by subacetate of lead (p. 481) and filtered. An observation 
tube is filled with the clear solution and the polariscope reading noted. 
A measured portion of the same solution is then treated with one-tenth its 
volume of concentrated hydrochloric acid and is subjected to inversion 
(p. 483), after which the same tube as before is filled with the inverted 
solution and a second reading obtained, one-tenth of the observed reading 
being added for the true invert polariscopic reading. If the two readings 
are virtually the same, sucrose is absent, but, in the presence of sucrose, 
the second reading will be considerably lower than the first or may even 
be to the left of the zero. 

(b) Test with Nitrate oj Cobalt* — Prepare a 5% solution of cobaltous 
nitrate, and a 50% solution of potassium hydroxide. If the sugar solution 
to be tested contains dextrin or gums, these should first be removed 
by treatment with alcohol. 15 cc. of the sugar solution to be tested are 
mixed with 5 cc. of the cobaltous nitrate reagent, and 2 cc. of the potas- 
sium hydroxide solution are added. Sucrose produces under these con- 
ditions a permanent amethyst-blue color, while dextrose gives at first a 
turquoise-blue passing over into light green. In a mixture of the two 
sugars the color due to sucrose will predominate. 

According to Wiley, i part of sucrose in 9 parts of dextrose may be 
detected by this test. 

Analysis of Cane sugar. — In the case of commercial granulated or 
loaf sugar the sucrose determination is usually all that is necessary 
to determine its purity, and the same is true, as a rule, of the powdered 
white sugars. A fairly complete analysis of raw or brown sugar con- 
sists in the determinations of moisture, sucrose, invert sugar, ash, organic 
non-sugars, and quotient of purity. Care should be taken that the 
portion subjected to analysis is a fair representation of the whole, and is 
perfectly homogeneous. 

* Wiley, Ag. Anal., p. 189. 



SUGAR AUD SACCHARINE PRODUCTS. 481 

Determination of Moisture. — 5 grams of the sample are carefully 
weighed in a flat, tared platinum dish, and dried to constant weight in 
vacuo, or in a McGill oven* in a current of air, at a temperature not 
exceeding 70° C. Formerly it was customary to dry sugars at 100°, but 
it has recently been shown that at a temperature in excess of 70° the 
levulose becomes dehydrated. 

Determination of the Ash. — The residue from the moisture deter- 
mination is burned slowly and cautiously over a low flame until frothing 
has ceased. Afterwards increase the flame and ignite to a white ash 
at a low, red heat. 

In igniting saccharine substances which contain an appreciable amount 
of cane sugar, the contents of the dish will swell up and froth, unless 
great care be taken, to such an extent as to flow over the sides of the 
dish, occasioning loss and inconvenience. Such frothing may be largely 
held in check by directing the flame at first down from above upon the 
pasty mass, instead of from under the dish as ordinarily, till all is reduced 
to a dry char, afterwards continuing the ignition from below in the usual 
manner. 

Organic Non-sugars. — These consist mainly of compounds of organic 
acids, together with gum, coloring matter, albuminous bodies, etc. They 
are determined by difference between 100% and the sum of the sucrose, 
invert sugar, moisture, and ash. 

Quotient of Purity. — By this term is meant the percentage of pure 
sugar in the dry substance. It is calculated by dividing the per cent 
of total solids by the percentage of sucrose and multiplying the result 
by 100. 

Determination of Sucrose by the Polariscope. — Reagents. — Subace- 
tate oj Lead Soliition.'\ — This is prepared by boiling for half an hour 430 
grams of normal lead acetate, 130 grams of litharge, and 1000 cc. of 

* A. McGill, Laboratory of Inland Revenue, Ottawa, Canada, has devised a forced- 
draft water-oven for drying at temperatures between 60° and 90° C. The oven is heated 
by means of ordinary gas-burners, and the temperature is controlled by introducing at the 
bottom of the oven a blast of air from a blower run by a small water-motor. Before dis- 
charging into the oven, the air-tube enters the water-chamber and is coiled a number of 
times in order to sufficiently warm the air before it enters the oven. The exit end of the 
air-tube is covered with a concavo-convex disk in order to distribute the blast and to pre- 
vent harmful currents. By regulating the burners and the flow of air, a fairly constant tem- 
perature can be obtained. The bottom of the oven is curved instead of flat, to prevent 
bumping when the water is boiling; a perforated plate serves as a false bottom. 

f v. S. P. lead subacetate may be used. This is sometimes sold under the name of 
Goulard's extract. 



482 



FOOD INSPECTION AND AN/1 LYSIS. 



water. The mixture is allowed to cool and settle, when the super- 
natant liquid is diluted to 1.25 specific gravity with recently boiled water. 

Alumina Cream is prepared by dividing a cold, saturated, aqueous 
solution of alum into two unequal portions, to the larger of which add a 
slight excess of ammonia. Then add by degrees the remaining portion 
to a faint acid reaction. 

Process. — If the Solcil-Ventzke polariscope is to be used, weigh out 26.048 
grams of the sugar, which may conveniently be done in the German-silver, 
tared tray especially designed for this purpose, and which accompanies the 
Schmidt and Haensch polariscope, Fig. 105. If any other instrument than 




Fig. 105. — German-silver Sugar-tray with Tare. 



the Soleil-Ventzke is employed, weigh out tlie standard or normal weight 
for that instrument (see p. 478). Transfer the sugar by washing to a 
loo-cc. graduated sugar-fia^k, and if the solution is perfectly clear, as 
would be the case with a refined sugar, make up to the mark and shake 
to insure a uniform solution. If the solution is slightly turbid, or more 
or less opaque or dark-colored, a clarifier must be added before making 
up to the mark to obtain a clear solution for polarization. The kind 




Fig. 106. — A Convenient Sugar-scale. 

and amount of clarifier to be used depends on the nature of the sugar 
solution, and experience will soon indicate what is best adapted to given 
conditions. If the turpidity is only slight, from 5 to 10 cc. of alumina 
cream alone will often prove sufficient. In case of a very opaque solution, 
10 cc. of subacetate of lead solution will nearly always suffice. 



SUGAR AND SACCHARINE PRODUCTS. 483 

For additional details as to clarification see page 502, under Molasses. 
After adding the clarifier, the flask is filled to the mark with water 
and shaken, the solution being poured upon a dry filter and the first 
few cubic centimeters of the fiUrate rejected. A 200-ram. observation- 
tube is filled with the clear sugar solution and the polarization noted. 
If sucrose is the only optically active substance present, the direct read- 
ing on the polariscope will indicate its percentage. 

Process 0} Inversion. — In the presence of invert or other sugars the 
normal solution as above prepared is subjected to inversion as follows: 
Take 50 cc. of the above clear sugar solution or of the clarified filtrate, 
and add 5 cc. of concentrated hydrochloric acid. For this purpose a 
flask graduated both to 50 and 55 cc. is convenient. Place the flask 
containing this mixture in water and heat the water gradually till a ther- 
mometer in the flask indicates 68° C, maintaining it at between 68° and 
70° for five minutes, after which remove the flask and let it cool to room 
temperature. Filter if necessary, fill a 220-mm. observation-tube with 
the clear solution, and take the second or invert reading. Or if a 220-mm. 
tube is not available, use the same tube as before (200 mm.) and add 
10% to the reading. Note the temperature at which the invert reading 
is taken. 

The sucrose is obtained by the following formula of Clerget, based on 
the rotation of cane sugar before and after inversion. 




where 5 = per cent of sucrose, a = direct polarization, 6 = invert polari- 
zation, and / = temperature. Note that if the direct polarization is to 
the right or positive, and the invert to the left or negative, then a — b would 
be the sum of the two polarizations. 

In many cases where it is almost impossible to obtain a colorless 
solution for polarization in the 200-mm. tube, a loo-mm. tube may be 
employed, and the readings multiplied by 2, or half the normal weight,* 
viz., 13.024 grams, of the sample may be taken and made up to 100 cc, 
the 200-mm. tube employed, and the readings multiplied by 2. 

* Wherever the term "normal weight" occurs hereafter will be meant, unless otherwise 
noted, the normal weight of sugar for the Soleil-Ventzke polariscope, viz., 26.048, and by a 
"normal solution" will be meant 26.04S grams in 100 cc. of water. Clerget 's formula, as 
originally worked out by him, was not based on this normal weight, but on 16.35 grams. 
It is, however, applicable to 26.048 grams. 



484 FOOD INSPECTION /IND AN /I LYSIS. 

The determination of sucrose by the Clerget formula is appUcable 
to all mixtures of the common sugars excepting those in which lactose, or 
milk sugar, is present. 

Theory oj Inversion. — On p. 461 a reaction is given showing that 
when sucrose is subjected to inversion by the action of dilute acids or 
of invertase or yeast it splits up into the two sugars dextrose and levulose, 
forming equal quantities of each. The dextrose is, however, dextro- 
rotary and the levulose laevorotary. Invert sugar is the term applied 
to the mixture of dextrose and levulose formed by the inversion of sucrose. 
The specific rotary power of sucrose varies so little with the temperature 
as to be regarded for practical purposes as constant. At 87° a solution 
of invert sugar polarizes at zero. This is due to the fact that the rotary 
power of levulose, unlike that of sucrose and dextrose, varies with the 
temperature. At from 87° to 88° the left-handed rotation of the levulose 
balances the right-handed rotation of the dextrose in the invert sugar, 
hence the zero reading. As the temperature decreases from 87°, the 
rotary power of the levulose proportionally increases, till at 0° the normal 
invert sugar solution would polarize 44° to the left of the zero. On these 
facts Clerget's formula (p. 483) is based, assuming that a normal solution 
of pure cane sugar polarizes at -f 100°, while after inversion the reading 
for 0° temperature would be —44° and would decrease half a degree 
for each degree in temperature above 0°. Thus at 20° the invert reading 
would be —34. 

For polariscopes graduated in angular degrees Tuchschmidt* gives 
the following formula for calculation of sucrose, 

31.31-.11/ 

wherein, as in Clerget's formula, S = per cent of sucrose, a = direct polariza- 
tion, 6 = invert polarization, and / = temperature of invert reading. 

Detection of Invert Sugar. — Methyl-blue Test. — This test depends on 
the decolorization of methyl blue by invert sugar. 20 grams of sugar are 
dissolved in water and made up to 100 cc. If the solution is not clear, 
sufficient subacetate of lead solution is added to clarify before making 
up to the mark, and the solution is filtered. Add to the fihrate enough 
10% sodium carbonate solution to make alkaline, and filter a second 
time. Take about 50 cc. of the fihrate in a casserole, add 2 drops of a 

* Landolt Handbook of the Polariscope, p. 189. 



SUG^R AND SACCHARINE PRODUCTS. 485 

1% solution of methyl blue, and boil over a free flame, noticing particu- 
larly the time the solution begins to boil. 

If the color disappears in one minute after boiling, there is present 
at least 0.01% of invert sugar. If it is not completely decolorized by 
three minutes' boiling, no invert sugar is present. 

Determination of Invert Sugar in Caxie Sugar Products by the Polar- 
Iscope. — While invert sugar is best determined by Fehling's solution as 
described elsewhere, it may be approximately estimated by the polari- 
scope, though less satisfactorily. On p. 508 a method is given for the 
determination of levulose by polariscopic readings at two different tem- 
peratures. Since invert sugar is composed of equal parts by weight 
of dextrose and levulose, the percentage of levulose multiplied by 2 would 
give that of invert sugar. 

SUGAR DETERMINATION BY COPPER REDUCTION. 

Various convenient methods of determining sugars depend on the 
readiness with which certain of them, known as reducing sugars, act on 
copper salts, especially on the tartrate of copper, reducing it to cuprous 
oxide. 

This reducing power is exercised in a definite degree under fixed 
conditions, so that the amount of reducing sugar present may be accurately 
determined. Of the common sugars, sucrose is the only one that has 
no direct reducing action, but on undergoing inversion it is converted 
into reducing sugars, which arc readily determined. 

Use of Fehling's Solution. — There are various well-known mixtures 
of copper sulphate, tartaric acid salts (usually Rochelle salts or cream 
of tartar), and alkalies, called after chemists who have employed them 
in the determination of the reducing sugars, each one possessing certain 
advantages, but none have become so widely adopted as Fehling's solu- 
tion, the use of which in one form or another is now well-nigh universal. 

There are a number of methods by which Fehling's solution is employed 
for this purpose, both volumetric and gravimetric. The former are 
simpler and quicker of manipulation, and thus are preferable for com- 
mercial work where extreme accuracy is not required. The gravimetric 
methods are usually considered more delicate and accurate, calling for 
less skill, but more time in arriving at results, and with less of the " per- 
sonal element" than the volumetric. 

Some modifications of the Fehling method, especially as carried out 
gravimetrically, differ for the various reducing sugars to be determined, 



486 FOOD INSPECTION AND ANALYSIS. 

and others are carried out alike, so far as manipulation is concerned, whether 
the particular sugar to be determined be dextrose, maltose, or lactose. 

While, strictly speaking, the reducing power of dextrose, levulose, and 
invert sugar are not identical, it is customary in commercial work to 
regard them as such, and no appreciable error arises in consequence 
except in extreme cases. Thus the term "reducing sugars" is com- 
monly applied indiscriminately to dextrose, levulose, and invert sugar, 
the same factor being used in calculating either, in mixtures wherein 
other reducing sugars, as lactose, maltose, etc., having widely different 
reducing powers are absent. 

I Fehling's solution is made up in two separate parts as follows: 
' ' A. Fehling's Copper Solution. — 34.639 grams of carefully selected 
crystals of pure copper sulphate dissolved in water and diluted to exactly 
500 cc. 

B. Fehling's Alkaline Tartrate Solution. — 178 grams Rochelle salts 
and 50 grams sodium hydroxide are dissolved in water and diluted to 
exactly 500 cc. 

The Feliling solution should be standardized by dissolving 0.5 gram 
of pure anhydrous dextrose in water, and diluting to exactly 100 cc. 10 cc. 
of this dextrose solution should exactly reduce the copper in 10 cc. of 
the Fehling (5 cc. each of solutions A and B) when conducted according 
to the volumetric process described below. 

f Volumetric Fehling Process. — For determining dextrose, levulose, or 
invert sugar in a raw or brown sugar, make a solution of the sugar of such 
a strength that an accurately weighed amount dissolved in water and 
made up to 100 cc. shall contain not more than 1% of the reducing sugar, 
as nearly as can be guessed at with reference to the class of sugar under 
examination, or from a rough preliminary titration. 

Measure accurately into a flask of about 250 cc. capacity 5 cc. Feh- 
ling's copper sulphate solution. A, and 5 cc. of the alkali solution, B. 
Add about 40 cc. of water, mix and boil over a free flame, with copper 
gauze beneath the flask. While still boiling, add from a pipette or burette 
a measured quantity of the sugar solution, prepared as above, until the 
copper after three minutes' boiling is all reduced to cuprous oxide. The 
end-point is determined in a variety of ways. Practice ^vill soon enable 
the eye to judge the near approach of the end-point by the changes in color 
that take place in the solution, which turns from a deep blue, first to green, 
then to a dull-red tint, and finally to a bright brick-red. The sugar- 
containing solution may be added from the burette quite rapidly uncil 



SUGAR AND SACCHARINE PRODUCTS. 



487 




the solution reaches the dull-red tint, after which care is taken to add a 
little at a time, keeping account of the total amount added. If the flask 
be removed from the flame, and the bright, diffused light from a window 
viewed through the solution with the eye on a level with the surface, a thin 
film scarcely wider than a line will be observed just below the surface 
(see Fig. 107), which is blue so long as some of the copper in the solu- 
tion remains unreduced. When, however, all the 
copper has been reduced, this lilm ceases to be 
blue and becomes colorless or yellow. 

If the film is not at once apparent, it may often 
be made quite noticeable by simply diluting the 
solution in the flask with water. At the approach 
of the end-point the sugar-containing solution 
should be added a very little at a time. The 
exact end-point is best arrived at by decanting a 
few drops of the mixture in the flask through a 
filter, acidifying the filtrate with acetic acid, and 
adding a drop of a solution of ferrocyanide of 
potassium. As long as there is unreduced copper 
present, a precipitate or brown-red coloration will 
appear when the ferrocyanide is added. The 
sugar solution toward the end should be added 
to the contents in the flask in small installments 
(say half a cubic centimeter each time), boiling 
the liquor for at least three minutes after each 
addition, until no brown-red coloration is pro- 
duced by adding the ferrocyanide to a little of the filtered acidified liquid. 
When the number of cubic centimeters of sugar solution necessary to 
reduce the copper has thus been determined, a second titration should be 
made to verify the first, running the entire amount of sugar-containing 
liquid found necessary- in the first case into the second flask. 

The equivalents of 10 cc. of Fehling's solution in the above volumetric 
method are, in terms of the common reducing sugars, as follows: 

i invert sugar, i 

0.05 gram of -, dextrose, or ,- will reduce 10 cc. FehHng's solution. 

( Icvulose ) 

( cane sugar ~j 

0.0475 gram of -, after in- Vwill reduce 10 cc. Fehling's solution. 

( version ) 



Fig. 107. — Flask and Con- 
tents used in Volumetric 
Fehling Determinations. 
Showing layer just be- 
neath the surface, the 
color of which indicates 
the end-point in adding 
the sugar-containing li- 
quid. 



488 FOOD INSPECTION AND ANALYSIS. 

0.0807 gram of maltose will reduce 10 cc. Fehling's solution. 

0.067 gram of lactose " " 10 cc. " " 

Suppose, for example, a sample of brown sugar is to be examined 
for invert sugar. This class of sugar has usually from 2 to 6 per cent 
of invert sugar. Hence, if 10 grams of the sample are dissolved in 100 
cc, the resulting solution will contain not more than 1% of invert sugar. 

Suppose 12.9 cc. of this 10% sugar solution were found by the above 
process to reduce 10 cc. of Fehling's solution. 

10 cc. Fehling's solution are equivalent to 0.05 gram invert sugar. 

Therefore 12.9 cc. of the sugar solution contain 0.05 gram invert- 
sugar. 

100 cc. sugar solution contain 10 grams sample, and 12.9 cc. contain 

1.29 grams sample, the equivalent of 0.05 gram invert sugar. 

0.05X100 
Hence per cent mvert sugar = =3-9- 

GRAVIMETRIC FEHLING PROCESSES. — In determining reducing sugars 
by gravimetric processes, a measured volume of the sugar solution is 
allowed to act upon a measured volume of hot Fehling's solution for a 
fixed time, thus forming cuprous oxide. This may be dried and weighed 
direct, but is more commonly converted either into oupric oxide by ignition, 
or into metallic copper by reduction with hydrogen or by electrolysis. 
In any case the sugar is calculated from the weight of the cuprous oxide, 
the cupric oxide, or the metallic copper (whichever method be used) by 
the employment of the proper factor, or by the use of tables compiled 
for the purpose. 

Note. — Much difference of opinion exists as to the best and most 
accurate Fehling gravimetric method to employ. For the determination 
of dextrose, the Association of Official Agricultural Chemists has given 
its approval to the AUihn method, wherein the cuprous oxide deposited 
is further reduced to metallic copper and the dextrose calculated from 
the copper by AUihn's table. 

The author for two reasons prefers the method of O'Sullivan as 
employed by Defren, \vith the use of the Defren tables, in accordance 
with which the reducing sugar is expressed in terms of its equivalence 
to cupric oxide, first because of its comparative simplicity, involving as it 
does less processes than the AUihn method (each additional process 
introducing a possible source of error), and, second, because the same 
method as carried out is applicable for the determination not only of 
dextrose, but also of maltose and lactose, Defren having worked out 



SUGAR AND SACCHARINE PRODUCTS. 489 

tables adapted for them all. With the exception of Defren's method 
and tables, the author knows of no single accurate method adapted with- 
out modification to the determination of the various reducing sugars, 
since in using the tables for dextrose, maltose, and lactose compiled by 
Allihn, Wein, and Soxhlet, the method employed must in each case be 
carried out in strict accordance to the minutest details adopted by each 
of the above authorities, and they are by no means uniform. 

The Defren-O'SuUivan Method.* — Mix 15 cc. of Fehling's copper 
solution, A (p. 486), with 15 cc. of the tartrate solution, B, in a quarter- 
liter Erlenmeyer flask, and add 50 cc. of distilled water. Place the flask 
and its contents in a boiling water bath and allow them to remain five 
minutes. Then nm rapidly from a burette into the hot liquor in the 
flask 25 cc. of the sugar solution to be tested (which should contain not 
more than one- half per cent of reducing sugar). Allow the flask to remain 
in the boiling water bath just fifteen minutes after the addition of the 
sugar solution, remove, and with the aid of a vacuum filter the contents 
rapidly in a platinum or porcelain Gooch crucible containing a layer 
of prepared asbestos fiber about i cm. thick, the Gooch with the asbestos 
having been previously ignited, cooled, and weighed. The cuprous 
oxide precipitate is thoroughly washed with boiling distilled water till 
the water ceases to be alkaline. 

The asbestos used should be of the long-fibered variety, and should 
be specially prepared as follows: Boil first with nitric acid (specific 
gravity 1.05 to i.io), washing out the acid with hot water, then boil with 
a 25% solution of sodium hydroxide, and finally wash out the alkali with 
hot water. Keep the asbestos in a wide-mouthed flask or bottle, and 
transfer it to the Gooch by shaking it up in the water and pouring it 
quickly into the crucible while under suction. 

Dry the Gooch with its contents in the oven, and finally heat to dull 
redness for fifteen minutes, during which the red cuprous oxide is con- 
verted into the black cupric oxide. If a platinum Gooch is used (and 
this variety is preferred by the writer), it may be heated directly over 
the low flame of a burner. If the Gooch is of porcelain, considerable 
care must be taken to avoid cracking the crucible, the heat being increased 
cautiously and the operation preferably conducted in a radiator or muflle. 
After oxidation as above, the crucible is transferred to a desiccator, cooled, 
and quickly weighed. From the milligrams of cupric oxide, calculate 
the milligrams of dextrose from the following table: 

* Jour. Am. Chem. Soc. 18 (1896), p. 749, and Tech. Quart. 10 (1897), p. 167. 



490 



FOOD INSPECTION AND /INALYSIS. 



DEFREN'S TABLE FOR THE DETERMINATION OF DEXTROSE, MALTOSE, 

AND LACTOSE. 



Milligrams 

of Cupric 

Oxide. 


Milligrams 


Milligrams 


Milligrams 


Milligrams 

of Cupric 

Oxide. 


Milligrams 


Milligrams 


Milligrams 


of Dextrose. 


of Maltose. 


of Lactose. 


of Dextrose. 


of Maltose. 


of Lactose. 


3° 


13-2 


21.7 


18.8 


80 


35-4 


58-1 


50. 5 


31 


13-7 


22.4 


19-5 


81 


35-9 


58-9 


51-1 


32 


14. 1 


23.1 


20.1 


82 


36-3 


59-6 


51-7 


33 


14.6 


23-9 


20.7 


?3 


36.8 


60.3 


52.4 


34 


15-° 


24.6 


21.4 


84 


37-2 


61. 1 


S3-0 


35 


lS-4 


25-3 


22 .0 


85 


37-7 


61.8 


53-6 


36 


iS-9 


26.1 


22.6 


86 


38-1 


62.5 


54.3 


37 


16.3 


26.8 


23-3 


87 


38-5 


63-3 


54-9 


38 


16.8 


27-5 


23-9 


88 


39-0 


64.0 


55-5 


39 


17.2 


28.3 


24-5 


89 


39-4 


64-7 


56.2 


40 


17.6 


29.0 


25.2 


90 


39-9 


65-5 


56.8 


41 


18. 1 


29.7 


25-8 


91 


4°-3 


66.2 


57-4 


42 


18.5 


30-5 


26.4 


92 


40.8 


66.9 


58-1 


43 


ig.o 


31.2 


27.1 


93 


41.2 


67.7 


58.7 


44 


19.4 


31-9 


27-7 


94 


41-7 


68.4 


59-3 


45 


19.9 


32-7 


28.3 


95 


42.1 


69.1 


60.0 


46 


20.3 


33-4 


29.0 


96 


42.5 


69.9 


60.6 


47 


20.7 


34-1 


29.6 


97 


43-° 


70.6 


61.2 


48 


21 .2 


34-8 


30-2 


98 


43-4 


71-3 


61.9 


49 


21.6 


35-5 


30.8 


99 


43-9 


72.1 


62. s 


50 


22.1 


36.2 


3' -5 


100 


44-4 


72.8 


63-2 


SI 


22.5 


37-° 


32-1 


lOI 


44.8 


73-5 


63.8 


52 


23.0 


^z-7 


32-7 


102 


45-3 


74-3 


64.4 


S3 


23-4 


38-4 


33-3 


i°3 


45-7 


75-° 


65-1 


54 


23.8 


39-2 


34-° 


104 


46.2 


75-7 


65-7 


55 


24.2 


39-9 


34-6 


105 


46.6 


76-S 


66.3 


S6 


24-7 


40.5 


35-2 


106 


47-° 


77-2 


67.0 


57 


25-1 


41-3 


35-9 


107 


47-5 


77-9 


67.6 


58 


25-S 


42.1 


36.5 


108 


48.0 


78-7 


68.2 


59 


26.0 


42.8 


37-' 


109 


48.4 


79-4 


68.9 


60 


26.4 


43-5 


37-8 


no 


48-9 


80.1 


69-5 


61 


26.9 


44-3 


38-4 


III 


49-3 


80.9 


70.1 


62 


27-3 


45-° 


39-° 


112 


49-8 


81.6 


70.8 


63 


27.8 


45-7 


39-7 


"3 


^0.2 


82.3 


71-4 


64 


28.2 


46-5 


40-3 


114 


5°-7 


83.1 


72.0 


65 


28.7 


47-2 


40.9 


115 


51-1 


83.8 


72.7 


66 


29.1 


47-9 


41.6 


116 


51-6 


84-5 


73-3 


67 


29-5 


48.6 


42.2 


117 


52.0 


85.2 


74.0 


68 


30.0 


49-4 


42.8 


118 


52-4 


85-9 


74-6 


69 


30-4 


5°-i 


43-5 


119 


52.9 


86.6 


75-2 


70 


30-9 


50.8 


44.1 


120 


53-3 


87-4 


75-9 


71 


31-3 


51.6 


44-7 


121 


53-8 


88.1 


76.6 


72 


31-8 


52-3 


45-4 


122 


54-2 


88.9 


77-2 


73 


32-2 


53-0 


46.0 


123 


54-7 


89.6 


77-9 


74 


32.6 


53-8 


46.6 


124 


55-1 


90-3 


78-S 


75 


33-1 


54-5 


47-3 


125 


55-6 


91. 1 


79-1 


76 


33-5 


55-2 


47-9 


126 


56.0 


91.8 


79.8 


77 


34-0 


s6.o 


48. 5 


127 


56.S 


92-5 


80.4 


78 


34-4 


56.7 


49.2 


128 


56-9 


93-3 


81. 1 


79 


34-9 


57-4 


49.8 


129 


57-3 


94-° 


81.7 



SUGAR AND SACCHARINE PRODUCTS. 



491 



DEFREN'S TABLE FOR THE DETERMINATION OF DEXTROSE, MALTOSE, 
AND LACTOSE— (Con^JKwed). 



Milligrams 

of Cupric 

Oxide. 


Milligrams 


Milligrams 


Milligrams 


Milligrams 

of Cupric 

O.xide. 


Milligrams 


Milligrams 


Milligrams 


of Dextrose. 


of Maltose. 


of Lactose. 


of Dextrose. 


of Maltose. 


of Lactose. 


130 , 


57-8 


94-8 


82.4 


180 


80.4 


131. 8 


114. 6 


131 


SS.2 


95-5 


83-0 


181 


80.8 


132-5 


115. 2 


132 


58.7 


96-2 


83.6 


182 


81.3 


133-2 


1 15. 8 


^ii 


59-1 


97.0 


84.2 


183 


81.8 


134-0 


116. 5 


134 


59-6 


97-7 


84-9 


184 


82.2 


134-7 


117. 1 


135 


60.0 


98-4 


85 -5 


185 


82.7 


i3=;-5 


117. 8 


136 


60.5 


99-2 


86.1 


186 


83.1 


136.2 


118. 4 


137 


60. g 


99.9 


86.8 


187 


83-5 


136.9 


119. 1 


138 


61.3 


100.7 


87-4 


188 


84.0 


137-7 


"9-7 


139 


61.8 


101.4 


88.1 


189 


84.4 


138.4 


120.4 


140 


62.2 


102. 1 


88.7 


190 


84-9 


I39-I 


121. 


141 


62.7 


102.8 


89-3 


191 


85-4 


139-9 


121.7 


142 


63-1 


103-5 


90.0 


192 


85-9 


140.6 


122.3 


143 


63.6 


104-3 


90.6 


193 


86.3 


141.4 


123.0 


144 


64.0 


105.0 


91-3 


194 


86.8 


142. 1 


123.6 


145 


64-5 


105.8 


91.9 


19s 


• 87.2 


142.8 


124-3 


146 


64.9 


106.5 


92.6 


196 


87-7 


143-6 


124.9 


147 


65-4 


107.2 


93-2 


197 


88.1 


144-3 


125.6 


148 


6.;. 8 


108.0 


93-9 


198 


88.6 


145-I 


126.2 


149 


66.3 


108.7 


94-5 


199 


89.0 


145-8 


126.9 


ISO 


66.8 


109.5 


95-2 


200 


89-5 


146.6 


127-S 


151 


67-3 


no. 2 


95-8 


201 


89.9 


147-3 


128.2 


152 


67.7 


III.O 


96-5 


202 


90-4 


148. 1 


128.8 


153 


68.3 


III. 7 


97-1 


203 


90.8 


148.8 


129.5 


154 


68.7 


112. 4 


97-8 


204 


91-3 


149.6 


130. 1 


155 


69.2 


113. 2 


98-4 


205 


91.7 


150-3 


130.8 


156 


69.6 


II3-9 


99.1 


206 


92.2 


151. 1 


131-5 


157 


70.0 


114-7 


99-7 


207 


92.6 


151.8 


132. 1 


158 


7°-5 


"5-4 


100.4 


208 


93-1 


152-5 


132.8 


159 


70.9 


116. 1 


loi .0 


209 


93-5 


153-3 


133-4 


160 


71-3 


116. 9 


101.7 


210 


94.0 


154-1 


134-1 


161 


71.8 


117. 6 


102.3 


211 


94-4 


154-8 


134-7 


162 


72-3 


118. 4 


103.0 


212 


94-9 


155-6 


135-4 


163 


72.7 


119. 1 


103.6 


213 


95-3 


156-3 


136.0 


164 


73-2 


119. 9 


104.3 


214 


95-8 


I57-I 


136-7 


'65 


73-6 


120.6 


104.9 


215 


96-3 


157-8 


137-3 


166 


74.1 


121. 4 


105.6 


216 


96.7 


158.6 


138.0 


167 


74-5 


122. 1 


106.2 


217 


97-2 


159-3 


138.6 


168 


74-9 


122.9 


106.9 


218 


97.6 


160.0 


139-3 


169 


75-4 


123.6 


107-5 


219 


98.1 


160.8 


139-9 


170 


75-8 


124.4 


108.2 


220 


98.6 


161. 5 


140.6 


171 


76-3 


125. 1 


108.8 


211 


99.0 


162.3 


141. 2 


172 


76.8 


125.8 


109-5 


222 


99-5 


163.0 


141-9 


173 


77-3 


126.6 


no. I 


223 


99-9 


163-7 


142.5 


174 


77-7 


127-3 


no. 8 


224 


100.4 


164-5 


143-2 


175 


78.2 


128. 1 


III. 4 


22s 


100. 9 


165-3 


143.8 


176 


78.6 


128.8 


112. 


226 


101.3 


166.0 


144. 5 


177 


79-1 


129-5 


112. 6 


227 


101.8 


166.8 


145-1 


178 


79-5 


130-3 


113-3 


228 


102.2 


167-5 


145.8 


179 


80.0 


131-0 


"3-9 


229 


102.7 


168.3 


146.4 



492 



FOOD INSPECTION AND ANALYSIS. 



DEFREN'S TABLE FOR THE DETERMINATION OF DEXTROSE, MALTOSE, 
AND LACTOSE— (Cottc/Kiei). 



Milligrams 

of Cupric 

Oxide. 


Milligrams 


Milligrams 


Milligrams 


Milligrams 

of Cupric 

Oxide. 


Milligrams 


Milligrams 


Milligrams 


of Dextrose. 


of Maltose. 


of Lactose. 


of Dextrose. 


of Maltose. 


of Lactose. 


230 


103. 1 


169. 1 


147.0 


280 


126.1 


206.8 


179.6 


231 


103.6 


169.8 


147-7 


281 


126.5 


207-5 


180.2 


232 


104.0 


170.6 


148.3 


282 


127.0 


208.3 


180.9 


^11 


104-5 


171-3 


149.0 


283 


127.4 


209.0 


181.5 


=34 


105.0 


1 72. 1 


149.6 


284 


127.9 


209.8 


182.2 


235 


105-4 


172.8 


150-3 


285 


128.3 


210.5 


182.9 


236 


105-9 


173-6 


150-9 


286 


128.8 


211.3 


183-6 


237 


106.^ 


174-3 


151.6 


287 


129-3 


212.1 


184.2 


238 


106.8 


175-I 


152.2 


288 


129.7 


212.8 


184.9 


239 


107.2 


175-8 


152-9 


289 


130.2 


213.6 


185-6 


240 


107.7 


176.6 


153-5 


290 


130.6 


214-3 


186.2 


241 


108.1 


177-3 


154- 2 


291 


131.1 


215.1 


186.9 


242 


108.6 


178. 1 


154-8 


292 


131-5 


215-9 


187.6 


243 


109.0 


178.8 


155-5 


293 


132.0 


216.6 


188.2 


244 


109-5 


179.6 


156. 1 


294 


'32-5 


217.4 


188.9 


245 


109.9 


180.3 


156.8 


295 


133-0 


218.2 


189.5 


246 


no. 4 


181. 1 


157-4 


296 


133-4 


218.9 


190.2 


247 


no. 9 


181. 8 


158. 1 


297 


133-9 


219.7 


190.8 


248 


III. 3 


182.6 


158-7 


298 


134-3 


220.4 


191-5 


249 


III. 8 


183-3 


159-4 


299 


134-8 


221.2 


192. 1 


250 


112. 3 


184. 1 


160.0 


300 


135-3 


221.9 


192.8 


251 


112. 7 


184.8 


160.7 


301 


135-7 


222.7 


193-4 


252 


113. 2 


185-5 


161. 3 


302 


136.2 


223-5 


194. 1 


253 


113-7 


186.3 


162.0 


303 


136.6 


224.2 


194-7 


254 


114. 1 


187.1 


162.6 


304 


137-1 


225.0 


195-3 


255 


114. 6 


187.8 


163-3 


30s 


137-6 


225.8 


196.0 


256 


1 1 5 . 


188.6 


163.9 


306 


138.0 


226.5 


196.6 


257 


1 15. 5 


189-3 


164.6 


307 


138-5 


227.3 


197-3 


258 


116. 


190. 1 


165.2 


308 


138-9 


228.1 


197-9 


259 


116. 4 


190.8 


165.9 


309 


139-4 


228.8 


198.6 


260 


116. 9 


191. 6 


166.5 


310 


139-9 


229.6 


199-3 


261 


II7-3 


192.4 


167.2 


311 


140.3 


230.4 


199-9 


262 


117. 8 


193 -I 


167.8 


312 


140.8 


231-1 


200.6 


263 


118. 3 


193-9 


168. 1 


313 


141. 2 


231-9 


201.3 


264 


118. 7 


194.6 


169.5 


314 


141.7 


232-7 


202.0 


265 


119. 2 


195-4 


169.8 


315 


142.2 


233-4 


202.6 


266 


119. 6 


196. 1 


170-4 


316 


142.6 


234-2 


203.3 


267 


120. 1 


196.9 


171. 1 


317 


143-1 


234-9 


203.9 


268 


120.6 


197-7 


171-7 


318 


143-6 


235-7 


204.6 


269 


121. 


198.4 


172.4 


319 


144.0 


236-5 


205-3 


270 


121. 4 


199.2 


173-0 


320 


144-S 


237.2 


205.9 


271 


121. 9 


199.9 


173-7 










272 


122.4 


200.7 


174-4 










273 


122.8 


201.5 


175-0 










274 


123-5 


202.2 


175-7 










275 


123.7 


203.0 


176-3 










276 


124.2 


203.7 


177.0 










277 


124.6 


204.5 


177.6 










278 


125. 1 


205 . 2 


178-3 










2-Q 


12^.6 


206.0 


178.0 











SUG/tR AND SACCHARINE PRODUCTS. 493 

AUihn's Method for the Determination of Dextrose.* — Place 30 cc. 
of Fehling's copper solution, 30 cc. of the alkaline tartrate solution, 
and 60 cc. of water in a beaker and heat to boiling. Add 25 cc. of the 
sugar solution, which must be so prepared as not to contain more than 1% 
dextrose, and boil over the flame for two minutes. Filter immediately 
without diluting through a Gooch crucible containing a layer of asbes- 
tos fiber, prepared as described on page 489, and wash thorouglily with hot 
water, using reduced pressure. Transfer the asbestos fiber and the adher- 
ing cuprous oxide by means of a glass rod to a beaker and rinse the cru- 
cible with about 30 cc. of a boiling mixture of dilute sulphuric and nitric 
acids containing 65 cc. of sulphuric acid (specific gravity 1.84) and 50 cc. 
of nitric acid (specific gravity 1.42) per liter. Heat and agitate till the 
solution is complete, then filter into a scrupulously clean, tared platinum 
dish of 100 cc. capacity, taking care to wash out all the copper solution 
from the filter into the dish. Deposit the copper elect rolytically in the 
platinum dish and weigh. Determine the de.xtrose from AUihn's table, 
p. 494. 

Or, the metallic copper may be calculated by means of the factor 
0.7986 from the cupric oxide obtained as in Defren's method (p. 489) 
and AUihn's table used. 

Or, the cuprous oxide as directly obtained by either AUihn's or Defren's 
method may be washed with alcohol and ether, dried for twenty minutes 
at 100° C, and weighed, its equivalent in dextrose being ascertained from 
AUihn's table. 

Electrolytic Apparatus. — The author has devised the apparatus shown 
in Fig. 108 for the electrolytic deposition of copper in sugar analysis and for 
other work of like nature. A, Fig. 109, is a hard-rubber plate 50 cm. 
long and 25 cm. wide provided with four insulated metal binding posts, B, 
each carr}'ing at the top a thumb screw by which a coiled platinum wire 
electrode, C, may be attached. In front of each post is a copper plate 
about 4 cm. square covered with thin platinum foil, P, which is bent 
around the edges of the copper plate and so held in place, the copper plate 
being screwed to the rubber from beneath. On the square platinum- 
covered plate is set the platinum evaporating-dish which holds the solu- 
tion from which the copper is to be deposited, the inside of the dish form- 
ing the cathode, while the electrode C, dipping below the surface of the 
solution, forms the anode. In front of each platinum-covered plate 
is a switch, S, and at either end of the hard-rubber plate is a binding 

* Jour, fur praktische Chemie, 22 (1880), p. 46. 



494 



FOOD INSPECTION AND ANALYSIS. 



ALLIHN'S TABLE FOR THE DETERMINATION OF DEXTROSE. 


* 


Milli- 


MilU- 


MilU- 


Milli- 


MilU- 


MilH- 


MilU- 


Milli- 


MilU- 


Milli- 


Milli- 


Milli- 


grams 


grams 


grams 


grams 


grams 


grams 


grams 


grams 


grams 


grams 


grams 


grams 


of 


of Cu- 


of 


of 


of Cu- 


of 


of 


of Cu- 


of 


of 


of Cu- 


of 


Cop- 


prous 
Oxide. 


Dex- 


Cop- 


prous 


Dex- 


Cop- 


prous 
Oxide. 


Dex- 


Cop- 


prous 


Dex- 


per. 


trose. 


per. 


Oxide. 


trose. 


per. 


trose- 


per. 


Oxide. 


trose. 


II 


12.4 


6.6 


76 


85.6 


38.8 


141 


158.7 


71-8 


206 


231-9 


105.8 


I 2 


I3-S 


V-i 


77 


86.7 


39-3 


142 


IS9-9 


72-3 


207 


233-0 


106.3 


13 


14.6 


7.6 


78 


87.8 


39-8 


143 


161 .0 


72.9 


208 


234-2 


106.8 


14 


lS-8 


8.1 


79 


88.9 


40-3 


144 


162. 1 


73-4 


209 


235-3 


107.4 


IS 


16.9 


8.6 


80 


90.1 


40-8 


14s 


163. 2 


73-9 


210 


236-4 


107.9 


16 


18.0 


9.0 


81 


91.2 


41-3 


146 


164,4 


74-4 


2n 


237-6 


108-4 


17 


19. 1 


9-5 


82 


923 


41-8 


147 


165.5 


74-9 


212 


238-7 


109,0 


18 


20.3 


lO.O 


83 


93.4 


42-3 


148 


166-6 


75-5 


213 


239-8 


109,5 


19 


21 .4 


10. 5 


84 


94.6 


42.8 


149 


167-7 


76.0 


214 


240-9 


I lO.O 


20 


22. S 


11. 


85 


95-7 


43-4 


150 


168.9 


76-S 


215 


242.1 


110,6 


21 


23.6 


11.5 


86 


96.8 


43-9 


151 


170.0 


77.0 


216 


243-2 


111 . I 


22 


24.8 


12.0 


87 


97-9 


44-4 


152 


171 .1 


77-5 


217 


244-3 


1 1 1 . 6 


23 


25 -9 


12. 5 


88 


99.1 


44-9 


153 


172.3 


78.1 


218 


245-4 


II 2. 1 


24 


27.0 


130 


89 


100.2 


45-4 


154 


173-4 


78.6 


219 


246,6 


112. 7 


25 


28.1 


13-5 


90 


101 .3 


45-9 


155 


174-5 


79-1 


220 


247,7 


113-2 


26 


29 -3 


I4.0 


91 


102.4 


46.4 


156 


175-6 


79-6 


221 


248.7 


113-7 


27 


30.4 


14s 


92 


103.6 


46-9 


157 


176.8 


80.1 


222 


249.9 


114-3 


28 


31-5 


iS.o 


9i 


104.7 


47-4 


158 


177-9 


80.7 


223 


251 -0 


114. 8 


29 


327 


iS-5 


94 


105.8 


47-9 


159 


179-0 


81-2 


224 


252.4 


115-3 


30 


33.8 


16.0 


95 


107 .0 


48-4 


160 


180.1 


81-7 


225 


253-3 


liS-9 


31 


34-9 


16. s 


96 


108. 1 


48-9 


161 


181.3 


82.2 


226 


254-4 


116.4 


32 


36.0 


I7-0 


97 


109. 2 


49-4 


162 


182.4 


82.7 


227 


255-6 


116,9 


33 


37- 2 


I7S 


98 


110.3 


49-9 


163 


183-5 


l^l 


228 


256-7 


117-4 


34 


38.3 


18.0 


99 


lii.S 


SO-4 


164 


184-6 


83.8 


229 


257-8 


118. 


35 


39-4 


18. 5 


100 


iia.6 


So-9 


l6s 


185.8 


84-3 


230 


25S.9 


118.5 


36 


40.5 


18.9 


lOI 


113. 7 


51-4 


166 


186.9 


84-8 


231 


260.1 


119. 


37 


41 -7 


19.4 


102 


114-8 


Si-9 


167 


188.0 


8S-3 


232 


261,2 


119-6 


38 


42.8 


19.9 


103 


116. 


52.4 


168 


189.1 


8s-9 


233 


262, 3 


120, I 


39 


43-9 


20.4 


104 


117. I 


52-9 


169 


190.3 


86-4 


234 


263-4 


120.7 


40 


45 -o 


20.9 


los 


11S.2 


53-5 


170 


191-4 


86-9. 


235 


264.6 


121,2 


41 


46.2 


21.4 


106 


II9-3 


54-0 


171 


192-S 


87-4 


236 


265.7 


121.7 


42 


47-3 


21.9 


107 


120.5 


54-5 


172 


193-6 


87-9 


237 


266.8 


122.5 


43 


48.4 


22.4 


108 


121 .6 


55-0 


173 


194-8 


88.5 


238 


268.0 


122.8 


44 


49 -S 


22.9 


109 


122.7 


55-5 


174 


195-9 


89.0 


239 


269- 1 


123.4 


45 


SO. 7 


23-4 


no 


123.8 


56-0 


17s 


197.0 


89. 5 


240 


270.2 


123.9 


46 


51.8 


239 


III 


125.0 


56-5 


176 


198-1 


90.0 


241 


271-3 


124.4 


47 


S2-9 


24.4 


112 


126. 1 


S7-0 


177 


199-3 


90. s 


242 


272.5 


125.0 


48 


54-0 


24.9 


113 


127.2 


57-5 


178 


200 -4 


91. I 


243 


273-6 


125. 5 


49 


55- 2 


25-4 


114 


128.3 


S8-0 


179 


201 -5 


91-6 


244 


274-7 


126.0 


50 


56.3 


25-9 


115 


129.6 


58-6 


180 


202.6 


92-1 


245 


275-8 


126,6 


SI 


57-4 


26.4 


116 


130.6 


59-1 


181 


203-8 


92.6 


246 


277-0 


127, 1 


52 


58.5 


26.9 


117 


131. 7 


59-6 


182 


204-9 


93-1 


247 


278-1 


127.6 


53 


59-7 


274 


118 


132.8 


60. 1 


183 


206-0 


93-7 


248 


279-2 


128,1 


54 


60.8 


27.9 


119 


1340 


60-6 


184 


207. 1 


94-2 


249 


280,3 


128,7 


55 


61 .9 


28.4 


120 


135-1 


61. 1 


18s 


208-3 


94-7 


250 


281-5 


129, 2 


56 


63.0 


28.8 


121 


136-2 


61.6 


1S6 


209-4 


95-2 


251 


282.6 


129-7 


57 


64.2 


29-3 


122 


137-4 


62.1 


187 


210. 5 


95-7 


252 


283.7 


1 30 - 3 


58 


65.3 


29.8 


123 


138-5 


62.6 


188 


211 -7 


96-3 


253 


284. 8 


I30-S 


59 


66.4 


30.3 


124 


139-6 


63.1 


189 


212.8 


96 8 


254 


286.0 


131-4 


60 


67.6 


30.8 


125 


140.7 


63-7 


190 


213-9 


97-3 


255 


287.1 


131-9 


61 


68.7 


31-3 


126 


141-9 


64-2 


191 


21S-0 


97-8 


256 


288.2 


132.4 


62 


69.8 


31-8 


127 


143-0 


64-7 


192 


216-2 


98-4 


257 


289.3 


133.0 


63 


70.9 


32-3 


128 


144- 1 


6s -2 


193 


217-3 


98-9 


258 


290. s 


133-S 


64 


72.1 


32.8 


129 


145 -2 


6s-7 


194 


218-4 


99-4 


259 


291 -6 


134-r 


6s 


73-2 


33-3 


130 


146.4 


66.2 


195 


219-S 


100 -O 


260 


292-7 


134-6 


66 


74-3 


33-8 


131 


147-5 


66.7 


196 


220-7 


1 00 -5 


261 


293-8 


135-r 


67 


75-4 


34-3 


132 


148-6 


67.2 


197 


221 -8 


lor -0 


262 


295 -0 


135-7 


68 


76.6 


34-8 


133 


149-7 


67-7 


198 


222.9 


loi -5 


263 


296- 1 


136-2 


6g 


77-7 


35-3 


134 


150-9 


68-2 


199 


224.0 


102.0 


264 


297-2 


136-8 


70 


78.8 


35-8 


135 


152.0 


68.8 


200 


225- 2 


102.6 


265 


298.3 


137-3 


71 


79-9 


36.3 


136 


153-I 


69-3 


201 


226.3 


103.1 


266 


299. 5 


137-8 


72 


81. 1 


36.8 


137 


154-2 


69-8 


202 


227.4 


103-7 


267 


300.6 


138-4 


73 


82,2 


37-3 


138 


155-4 


70-3 


203 


228.5 


104. 2 


268 


301 .7 


138-9 


74 


83.3 


37.8 


139 


156-5 


70.8 


204 


229.7 


104-7 


269 


302.8 


I 39 -5 


75 


84.4 


38.3 


140 


157.6 


71-3 


20S 


230.8 


105-3 


270 


304.0 


140,0 



* U. S. Dept. of Agric. Bur. of Chem.. Bui. 65. p i43 



SUGAR AND SACCHARINE PRODUCTS. 



495 



ALLIHN'S TABLE FOR THE DETERMLNATION OF DEXTROSE— (Continued). 


MilU- 


Milli- 


MilU- 


Milli- 


Milli- 


Milli- 


Milli- 


Milli- 


Milli- 


Mim- 


Milli- 


Milli- 


grams 


grams 


grams 


grams 


grams 


grams 


grams 


grams 


grams 


grams 


grams 


grams 


of 


of Cu- 


of 


of 


of Cu- 


of 


of 


of Cu- 


of 


of 


of Cu- 


of 


Cop- 


prous 


Dex- 


Cop- 


prous 


Dex- 


Cop- 


prous 


Dex- 


Cop- 


prous 
Oxide. 


Dex- 


per. 


Oxide. 


trose. 


per. 


Oxide. 


trose. 


per. 


Oxide. 


trose. 


per. 


trose. 


271 


305.1 


140.6 


321 


361 .4 


168.1 


371 


417.7 


195.3 


421 


474.0 


335.1 


272 


306. 2 


I4I-I 


322 


362. s 


168.6 


373 


418.8 


196.8 


422 


475-6 


335.7 


273 


307 -3 


141.7 


323 


363.7 


169. 2 


373 


420. 


197-4 


423 


476.2 


336.3 


274 


308. s 


142.2 


324 


364.8 


169.7 


374 


421 . 1 


198.0 


434 


477.4 


336.9 


275 


309.6 


142. S 


32s 


365.9 


170-3 


375 


422. 2 


198.6 


435 


478.5 


337. 5 


276 


310.7 


143-3 


326 


367.0 


170.9 


376 


433-3 


199-r 


426 


479-6 


228.0 


277 


3II-9 


143-9 


327 


368.2 


171.4 


377 


434-5 


199-7 


427 


4S0.7 


228.6 


278 


3'3-° 


144.4 


328 


369.3 


172.0 


.578 


435-6 


300.3 


428 


481.9 


229. 2 


279 


314. 1 


1450 


329 


370.4 


172.5 


379 


426.7 


300.8 


429 


483-0 


229.8 


280 


3152 


145-5 


330 


371. 5 


I73-I 


380 


427-8 


301 .4 


430 


484. 1 


330.4 


281 


316-4 


146. I 


331 


372.7 


173-7 


381 


429.0 


202 .0 


431 


485-3 


331.0 


282 


3I7-S 


146.6 


332 


373.8 


174-2 


382 


430.1 


202.5 


432 


486.4 


331 .6 


283 


31S.6 


147.2 


333 


374-9 


174-8 


383 


431-2 


203. I 


433 


4S7.5 


232.2 


2S4 


3I9-7 


147-7 


334 


376.0 


I7S-3 


3f4 


433-3 


203.7 


434 


48S.6 


232.8 


28s 


320.9 


148.3 


335 


377.2 


175-9 


385 


433 -S 


204.3 


435 


489.7 


233.4 


286 


322.0 


148.8 


336 


378.3 


176.5 


386 


434-6 


204. 8 


436 


490.9 


233-9 


287 


3231 


149.4 


337 


379-4 


177.0 


387 


435-7 


30S-4 


437 


493.0 


234-S 


28S 


324.2 


149.9 


338 


380.5 


177.6 


388 


436.8 


3o6. 


438 


493-1 


235 I 


289 


325.4 


150.5 


339 


381-7 


17S.1 


389 


438.0 


306. 5 


439 


494-3 


235-7 


290 


326. s 


151.0 


340 


382.8 


178.7 


390 


439-1 


307. 1 


440 


495-4 


236. J 


291 


337.4 


151 .6 


341 


383 -9 


179.3 


391 


440.2 


207.7 


441 


406,5 


236.9 


292 


328.7 


152.1 


342 


385.0 


179-8 


392 


441-3 


208.3 


442 


497-6 


237-S 


293 


3299 


152-7 


343 


386.2 


180.4 


393 


442.4 


208.8 


443 


498.8 


238.1 


294 


3310 


153-2 


344 


387-3 


180.9 


394 


443-6 


209.4 


444 


499-9 


238.7 


395 


332.1 


153-8 


345 


388.4 


iSl.s 


395 


444-7 


210.0 


445 


501 .0 


339.3 


396 


333-3 


154-3 


346 


389.6 


182.1 


396 


445-9 


210.6 


446 


502. 1 


339-8 


297 


334-4 


154-9 


347 


390.7 


182.6 


397 


447-0 


211 . 2 


447 


503- 3 


240.4 


298 


335 -5 


iSS-4 


348 


391.8 


183.2 


398 


448-1 


211 .7 


448 


504-4 


241 .0 


299 


336.6 


156.0 


349 


392.9 


183.7 


399 


449-2 


213.3 


449 


505-5 


241 .6 


300 


337.8 


156. 5 


350 


394-0 


184.3 


400 


450.3 


212.9 


4SO 


S06-6 


242. 3 


301 


338.9 


157-I 


351 


395-3 


184-9 


401 


451-5 


213-5 


451 


507-8 


243.8 


302 


340.0 


IS7-6 


353 


396-3 


185.4 


402 


452.6 


214.1 


452 


508.9 


243-4 


303 


341-1 


15S-2 


353 


397-4 


186.0 


403 


453-7 


214.6 


453 


510.0 


244.0 


304 


342-3 


158.7 


354 


398.6 


i86.fi 


404 


454-8 


215.2 


454 


511.1 


244.6 


30s 


343-4 


159-3 


355 


399-7 


187.2 


40s 


456-0 


215.8 


455 


512. 3 


345. 3 


306 


344-5 


159-8 


3S6 


400. 8 


187.7 


406 


457-1 


"216.4 


456 


513-4 


345.7 


307 


345.6 


160. 4 


357 


401 .9 


1S8.3 


407 


458-3 


217.0 


457 


514-5 


346.3 


308 


346-8 


160.9 


358 


403-1 


188.9 


408 


459-4 


217.5 


458 


515-6 


346.9 


309 


347-9 


161 .5 


350 


404-2 


189.4 


409 


460 . 5 


218.1 


459 


S16.8 


347. 5 


310 


349 


162.0 


360 


405 -3 


190.0 


410 


461.6 


218.7 


460 


5170 


348.1 


311 


350.1 


162.6 


361 


406.4 


190.6 


411 


462.7 


219.3 


461 


519-0 


348.7 


312 


351-3 


163.1 


362 


407.6 


191 . 1 


412 


463.8 


219.9 


462 


520. 1 


249-3 


313 


352.4 


163.7 


363 


408.7 


191.7 


413 


465-0 


220.4 


463 


531-3 


249.9 


314 


3S3-S 


164. 2 


364 


409.8 


192.3 


414 


466-1 


221 .0 








31s 


354-6 


164.8 


36s 


410.9 


193.9 


415 


467.3 


221 .6 








316 


355-8 


165.3 


366 


412. I 


193.4 


4l6 


468.4 


222. 2 








317 


356-9 


165.9 


367 


413. 2 


194° 


417 


469-5 


222.8 








318 


358.0 


166.4 


368 


414.3 


194-6 


418 


470.6 


223.3 








319 


359-1 


167.0 


369 


415.4 


195- 1 


419 


471.8 


223-9 








320 


360.3 


167.5 


370 


416.6 


195-7 


420 


473.9 


224-S 









post, R, for connection with the electric current. The wiring, which 
is on the under side of the rubber plate, is best illustrated by the diagram 
in Fig. 109. 

Four determinations may be carried on simultaneously in four plat- 
inum dishes, if desired, the wiring and the switches being so arranged 
that beginning at one end of the plate either the first dish or the first 



FOOD INSPECTION AND AN /I LYSIS. 




Fig. io8. — Electrolytic Apparatus, with Glass-covered Top Partially Removed. 



£ 





i!5 ^ O 



K 



K 

Q 



Fig. log. — Diagrammatic Plan View of 4-Pan Electrolytic Apparatus. 



SUG/1R AND SACCHARINE PRODUCTS. 497 

two or the first three may be thrown in or out of circuit at will without 
interrupting the current through the remaining dishes. A cover with 
wooden sides and glass top tits closely over the whole apparatus as a 
protection from dust, but may be easily lifted off to manipulate the 
dishes when desired. The sides of the cover are perforated to permit 
the escape of the gas formed during the electrolysis. 

The ordinary street current is used when available, and the strength 
of the current may be varied within wide limits by means of a number 
of 16 or 32 candle-power lamps, K, coupled in multiple, and a rheostat, 
L, consisting of a vertical glass tube sealed at the bottom, containing a 
column of dilute acid, the resistance being changed by varying the length 
of the acid column contained between the two platinum terminals immersed 
therein, one of which is movable. A gravity battery of four cells may 
be employed if the laboratory is not equipped with electric lights. 

In using this apparatus for determining copper, as in sugar work, 
the plating process should go on till all the copper is deposited, requiring 
several hours or over night with a current strength of about 0.25 ampere. 
Before stopping the process, the absence of copper in the solution should 
be proved by removing a few drops with a pipette, adding first ammonia, 
then acetic acid, and testing with ferrocyanide of potassium. If no 
brown coloration is produced, all the copper has been plated out. Throw 
the dish out of circuit by means of the switch, pour out the acid solution 
quickly before it has a chance to dissolve any of the copper, wash the 
dish first with water and then with alcohol, dry, and weigh. 

The copper may be removed from the platinum dish by strong nitric 
acid. 

Determination of Sucrose by Fehling's Solution.* — If a polariscope is 
not available, cane sugar can be determined as follows : First determine the 
percentage of invert sugar present in the sample by one of the Fehling 
methods already described. Then dissolve i gram of the sugar in about 
100 cc. of water in a 500-cc. graduated flask, add 3 cc. of concentrated 
hydrochloric acid and invert by heating in water to 68° and cooling in the 
regular maimer. Neutralize with sodium hydroxide or sodium carbonate, 
and make up to the mark with water. Determine the per cent of total 
reducing sugar as invert sugar either by the volumetric or gravimetric 
Fehling process. Subtract the invert sugar found present in the sugar by 
direct determination from the total found present after inversion, and 

* Tucker, Manual of Sugar Analysis, p. 182. 



498 FOOD INSPECTION /1ND ANALYSIS. 

the remainder is the invert sugar due to cane sugar. This figure multi- 
plied by 0.95 gives the percentage of cane sugar. 

For the determination of sucrose by the gravimetric Fehling process on 
the inverted sample, multiply the cupric oxide (CuO) by the factor 0.4307, 
or the copper (Cu) by the factor 0.5394. 

Test for Ultramarine in Sugar.* — A large amount of the sugar is 
dissolved in water and the coloring matter is allowed to settle out, wash- 
ing the residue several times by decantation. On treatment with hydro- 
chloric acid, the blue color is discharged if due to ultramarine. 

Analysis of Molasses and Syrups. — First insure a perfectly homo- 
geneous sample by stirring with a rod to evenly distribute any separated 
sugar. 

Determination of Total Solids. — (i) Direct Method. — Weigh 20 
grams into a loo-cc. graduated flask, dissolve in water, and make up to 
the mark. Insure a uniform solution by shaking. Measure 10 cc. of 
this solution into a tared platinum dish containing about 5 grams of 
freshly ignited, iinely divided asbestos fiber, and dry to constant weight 
at 70° in vacuo, or in a McGill oven (see p. 481). 

(2) By Calculation from Specific Gravity. — Weigh 25 grams of the 
sample into a loo-cc. graduated flask, dissolve in water, and make up 
to the mark. Determine the specific gravity of the diluted solution by 
means of a pycnometer or Wcstphal balance. Ascertain from the accom- 
panying table the percentage by weight of solids (sugar) corresponding 
to the specific gravity of the diluted solution, and calculate the total solids 
in the original sample by the formula 

Solids in original sample = 4Z)5, 

D being the specific gravity of the diluted solution and 5 the per cent 
of solids in the diluted solution. 

Determination of Ash. — Weigh from 5 to 10 grams of the sample 
into a tared platinum dish, evaporate to dryness on the water-bath, and 
proceed as directed for ash of sugar (p. 481). 

Polarization and Determination of Sucrose. — Molasses and golden 
syrup require the application of clarifying reagents before a sufficiently 
clear solution can be obtained for reading on the polariscope. Even 
then it is not possible nor is it necessary to get a water-white solution, so 
that in this class of prod uct s greater accuracy can usually be attained by 

* Leffmann and Beam, Select Methods of Food Analysis, p. 126. 



SUGAR /1ND S/4CCHARINE PRODUCTS. 
RELATION OF BRIX, SPECIFIC GRAVITY, AND BAUME. 



499 



Per 




^6 


Per 




-s 


Per 






Per 




1) C 
Eirt 


Cent 


Specific 


Degre 
Bau! 


Cent 


Specific 




Cent 


Specific 


sl 


Cent 


Specific 


of 


Gravity. 


of 


Gravity. 


of 


Gravity. 


tort 


of 


Gravity. 


Sugar. 




Sugar. 




Sugar. 




Sugar. 




0. 1 


1 .0003 


0.06 


6.6 


1 .0261 


3.7 


13,1 


1.0531 


7-3 


19,6 


1.0815 


10.85 


O. 2 


I .0007 


0. 1 1 


6.7 


1 .0265 


3-7 


13.2 


1.0536 


7.3 


19,7 


1.0819 


10.9 


0-3 


1 .001 1 


0.17 


6.8 


1 .0269 


3.8 


13.3 


1 .0540 


7.4 


19,8 


1 .0824 


11 .0 


0.4 


I .0015 


0. 22 


6.9 


1 .0273 


3.8 


13.4 


1,0544 


7,4 


19.9 


1 .0828 


11.0 


0,5 


I .0019 


0.28 


7,0 


I .0277 


3,9 


13.5 


1 ,0548 


7-5 


20,0 


I .0832 


11 .1 


0.6 


1.0023 


0.33 


7-1 


I .0281 


3,9 


13.6 


I. 0553 


7,S 


20, 1 


1,0837 


II .1 


0.7 


I .0027 


0.39 


7,2 


1.0286 


4.0 


13.7 


I.OS57 


7,6 


20.2 


I ,0841 


II. 2 


0.8 


I .0031 


0.44 


7-3 


1 .0290 


4,1 


13.8 


I .0561 


7,65 


20.3 


1 ,0846 


11.2 


o.o 


I .0034 


0,5 


7-4 


1.0294 


4,1 


13,9 


1 ,0566 


7,7 


20.4 


I , o8=;o 


11.3 


I .o 


I .0038 


o,5S 


7-5 


1 .0298 


4,2 


14,0 


1,0570 


7,8 


20.5 


I. 0855 


11.3 


I . r 


I .0042 


0.6 


7.6 


I ,0302 


4.2 


14,1 


1,0574 


7,8 


20, 6 


1 .0859 


11.4 


1 . 2 


I .0046 


0.7 


7 7 


I .0306 


4.3 


14,2 


1.0578 


7,9 


20,7 


1 ,0864 


II.4S 


1.3 


I .0050 


0.7 


7.8 


1 .0310 


4-3 


14,3 


1.0583 


7,9 


20.8 


1,0868 


II. 5 


1-4 


1 .0054 


0.8 


7,9 


1,0314 


4.4 


14.4 


1,0587 


8,0 


20.9 


I 0873 


II. 6 


I .5 


I .0058 


0.8 


»,o 


I .0318 


4.4 


14-5 


1,0591 


8.0 


21 .0 


1.0877 


II. 5 


1.6 


I .0062 


0.9 


8.1 


1.0322 


4.5 


14,6 


1 .0596 


8,1 


21 . 1 


1,0882 


II. 7 


I -7 


I .0066 


0.9 


8.2 


I .0327 


4-55 


14.7 


1 .0600 


8.15 


21 . 2 


1,0886 


11-7 


1.8 


I .0070 


1 .0 


8.3 


1,0331 


4,6 


14,8 


I .0604 


8,2 


21,3 


I ,0891 


II. 8 


I .9 


1 .0074 


1.05 


8.4 


l,o33S 


4-7 


14,9 


I .0609 


8,3 


21,4 


I ,0895 


11 .8 


2.0 


I .0077 


1,1 


8.S 


I .0339 


4,7 


15,0 


1 .0613 


8,3 


21. S 


1 ,0900 


II .9 


2.1 


I .0081 


1 . 2 


8.6 


1.0343 


4,8 


IS. I 


1 .0617 


8,4 


21.6 


1 .0904 


1 1.9s 


2. 2 


I .0085 


1 . 2 


8.7 


1.0347 


4.8 


15,2 


I .0621 


8,4 


21.7 


I ,0909 


12.0 


2.3 


I .0080 


I .3 


8.8 


1.0351 


4.9 


IS, 3 


1 .0626 


8.5 


21.8 


1.0914 


1 2. OS 


2.4 


I .0003 


1.3 


8,9 


1 ,0353 


4.9 


15,4 


I .0630 


8.5 


21 .9 


1 .0918 


12.1 


2.5 


I .0097 


1-4 


9.0 


I.03S9 


S.o 


15-5 


1.0634 


8.6 


22.0 


1.0923 


12.2 


2.6 


I .oior 


1-4 


9.1 


1.0364 


S.05 


15.6 


1.0639 


8.6s 


22, 1 


1.0927 


12.2 


2.7 


1 ,010s 


1,5 


9.2 


1,0368 


.■i.l 


15,7 


1.0643 


8.7 


22. 2 


1.0932 


12.3 


2.8 


1 .0109 


1,55 


9-3 


1.0372 


S.2 


15.8 


1.0647 


8.8 


22.3 


1.0936 


12.3 


2.9 


I .01 13 


1.6 


9.4 


1,0376 


5-2 


15,9 


I .0652 


8.8 


22,4 


1.0941 


12.4 


3.0 


1 .0117 


1 ,7 


9-5 


1 ,0380 


5-3 


16.0 


1.0656 


8,9 


22.5 


1.0945 


12.4 


3-1 


1 .0121 


1,7 


9.6 


1 ,0384 


S.3 


16. 1 


I .0660 


8,9 


22.6 


1 .0950 


12. S 


3.2 


1 ,012s 


1.8 


9-7 


1.0388 


S.4 


16.2 


I .0665 


9.0 


22.7 


1.0954 


12. 5S 


3.3 


1 .0129 


1,8 


9.8 


1,0393 


5-4 


16.3 


I .0669 


9.0 


22.8 


1.0959 


12.5 


3-4 


I. 0133 


1 ,9 


9,9 


1,0397 


5.5 


16.4 


I .0674 


9.1 


22.9 


I .0964 


12.7 


3.5 


I .0137 


1 .9 


10. 


I ,0401 


S.SS 


16. s 


1.0678 


9.1 


23.0 


1 .0968 


12.7 


3.6 


I .0141 


2.0 


10. 1 


1 .0405 


S.6 


16.6 


1.0682 


9.2 


23,1 


1.0973 


12.8 


3.7 


1 .014s 


2.0 


10.2 


I ,0409 


5.7 


16.7 


1.0687 


9.2s 


23,2 


1.0977 


12.8 


3.8 


I ,0149 


2.1 


i°.3 


1 .0413 


S.7 


16.8 


1 .0691 


9,3 


23,3 


I .0982 


12.9 


3-9 


i,oi53 


2.2 


10.4 


1 .0418 


S.8 


16.9 


1.069s 


9,4 


23,4 


I .0986 


12.9 


4.0 


1.0157 


2. 2 


10.5 


I .0422 


5.8 


17,0 


I .0700 


9,4 


23,5 


1 .0991 


13.0 


4.1 


I .0161 


2.3 


10.6 


1.0426 


59 


17. 1 


1.0704 


95 


23.6 


1 .0996 


I3.0 


4.2 


I .0165 


2.3 


10.7 


1.0430 


59 


17.2 


I .0709 


93 


23.7 


1 .1000 


13-1 


4-3 


I .0169 


2-4 


10.8 


I . 0434 


6.0 


17.3 


1.0713 


9.6 


23.8 


I . 1005 


13. IS 


4.4 


1 .0173 


2.4 


10.9 


1,0439 


6.0s 


17.4 


1.0717 


9,6 


23.9 


1 .loog 


13.2 


4-5 


1.0177 


2.5 


11 .0 


I -0443 


6.1 


17. 5 


1 .0722 


9-7 


24.0 


1 .1014 


13.3 


4.6 


I .0181 


2.6 


11. 1 


1.0447 


6.2 


17.6 


I .0726 


9.7s 


24.1 


1 .1019 


13,3 


4-7 


1 .0185 


2.6 


11 .2 


1.0451 


6.2 


17.7 


1.0730 


9.8 


24.2 


I . 1023 


13,4 


4.8 


I .0189 


2.7 


11-3 


I ,0455 


6.3 


17.8 


1.0735 


9.9 


24-3 


1 . 1028 


13,4 


4.9 


1.0193 


2,7 


11.4 


I. 0459 


6.3 


17.9 


1 .0739 


9,9 


24.4 


I .1032 


13. 5 


5-0 


1,0197 


2,8 


II. S 


1 .0464 


6.4 


18.0 


1.0744 


10.0 


24. S 


I .1037 


13.5 


S.I 


1 ,0201 


2.8 


II. 6 


1.0468 


6.4 


18.1 


1.0748 


10,0 


24.6 


I . 1042 


13.6 


5-2 


1 .0205 


2,9 


II. 7 


I .0472 


6.5 


18.2 


I.07S3 


10,1 


24.7 


1 . 1046 


13-6 


5-3 


1 .0209 


2.9 


11.8 


1.0476 


6.5s 


18,3 


I .0757 


10, I 


24.8 


1 . 1051 


137 


S.4 


1.0213 


3,0 


11.9 


1 .0481 


6.6 


18,4 


I .0761 


10, 2 


24.9 


1 . 1056 


13.7s 


5-5 


I .0217 


3,0 


12.0 


1.048s 


6.7 


18,5 


I .0766 


10,2 


25,0 


I . 1060 


13.8 


5-6 


1 ,0221 


3-1 


12,1 


I .0489 


6.7 


iS,6 


1.0770 


10.3 


25.1 


1 .1065 


13.9 


5.7 


1 ,0225 


3.2 


12.2 


I .0493 


6.8 


18,7 


I .0775 


10.35 


25.2 


I . 1070 


13.9 


5.8 


1 .0229 


3.2 


12.3 


1.0497 


6.8 


18,8 


1.0779 


10.4 


25,3 


I .1074 


14.0 


59 


I .0233 


3-3 


12.4 


1 .0502 


6.9 


18,9 


1.07S3 


10.5 


25,4 


I. 1079 


14.0 


6.0 


1.0237 


3.3 


12. S 


1.0506 


6.9 


19,0 


1.0788 


10. s 


25,5 


1 .1083 


14.1 


6.1 


1 .0241 


3-4 


12.6 


1.0510 


7.0 


19,1 


1.0792 


10. 6 


25,6 


I .1088 


14.1 


6,2 


1,024s 


3-4 


12.7 


1.0514 


7.0s 


19,2 


1.0797 


10.6 


25.7 


1.1093 


14,2 


6.3 


1.0249 


3.5 


12.8 


1.0519 


7.1 


19,3 


1.0801 


10.7 


25,8 


I. 1097 


14,2 


6.4 


1,0253 


3.6 


12.9 


1.0523 


7.2 


19.4 


1 .0806 


10.7 


25,9 


I . 1102 


14,3 


6-5 


1.0257 


3-6 


13.0 


1.0527 


7.2 


19.5 


I .0810 


10. 8 


26,0 


I . 1107 


■4,3s 



5°° 



FOOD INSPECTION AND ANALYSIS. 



RELATION OF BRIX, SPECIFIC GRAVITY, AND JiPiXSMY.— {Continued). 



Per 




up 1 


Per : 


0) S 


Per 




4> c 


Per 




(3« 


Cent 


specific 


Degre 
Baui 


Cent ' Specific 


t^3 


Cent 


Specific 


ti 


Cent 


Specific 


of 


Gravity. 


of 1 Gravity- 


17-9 


of 


Gravity- 




of 


Gravity. 1 


Sugar. 




Sugar. 


Sugar. 




Sugar. 


1 


26,1 


1 .1111 


14.4 1 


32.6 1 1.1422 


391 


1. 1748 


21 .4 


45-6 


I . 2088 


24.9 


26. 2 


I . II 16 


14-5 


32.7 : I. 1427 


18.0 


39-2 


I. 1753 


21-S 


45-7 


1.2093 


24.9 


26.3 


1 . 1121 


14-5 


32.8 1 1.1432 


18.0 


39-3 


1.1758 


21. 5 


45-8 


1 . 2099 


25.0 


26.4 


I . II2S 


14.6 


32.9 ; 1.1437 


18.1 


39-4 


1-1763 


21.6 


45.9 


1 . 2 1 04 


2S-0 


26. s 


I . II30 


14.6 


33.0 1 1.1442 


18.15 


39 -S 


1.1768 


21.6 


46.0 


1 . 21 10 


25-1 


26.6 


1-1I3S 


14-7 


33-1 


1.1447 


18.2 


39-6 


1.1773 


21-7 


46.1 


1 . 2115 


25 -I 


25.7 


I . 1 1 4c 


14-7 


33.2 


I. 1452 


iB. 25 


39-7 


1.1778 


21 .7 


46. 2 


1 . 2120 


25-2 


26.1, 


1. 1 1 44 


14.8 


33.3 


I. 1457 


18.3 


39-8 


1.1784 


21.8 


46.3 


I . 2126 


25.2 


26.9 


1. 1 149 


14.8 


33-4 


I .1462 


18.4 


39-9 


I. 1789 


21.85 


46.4 


I .2131 


25-3 


27.0 


I .1154 


14.9 


33-5 


I . 1466 


18.4 


40.0 


1. 1 794 


21.9 


46.5 


I .2136 


25. 35 


27-1 


1.1158 


14.9 


33-6 


1.1471 


18.5 


40.1 


I. I 799 


22.0 


46.6 


I . 2142 


25-4 


27.2 


1. 1 1 63 


I5-0 


33-7 


1 - 1476 


18.5 


40.2 


I. 1 804 


22.0 


46.7 


I .2147 


25-4S 


27-3 


1.1168 


IS. I 


33-8 


1 . 1481 


1S.6 


40-3 


I . I 809 


22. 1 


45.8 


1-2153 


2S-S 


27.4 


1 .1172 


IS. I 


33-9 


1.1485 


18.6 


40.4 


I .1815 


22. 1 


46.9 


1-2158 


25-6 


27-5 


1.1177 


15.2 


34-0 


I. 1491 


18.7 


40-S 


I. 1820 


22". 2 


47.0 


1 -2163 


25.6 


27.6 


1.1182 


15-2 


34-1 


1.1496 


18.7 


40.6 


1.1825 


22. 2 


47-1 


1 . 2 1 69 


257 


27.7 


I .1187 


15-3 


34-2 


1.1501 


18.8 


40.7 


1.1830 


22.3 


47-2 


I .2174 


25-7 


27.8 


I . 1 191 


15-3 


34-3 


I .1505 


18.85 


40.8 


1.1S35 


22.3 


47-3 


I . 2 1 So 


=5? 


27.9 


1 . 1196 


15-4 


34-4 


1 .1511 


18.9 


40.9 


I . 1840 


22.4 


47-4 


I .2185 


25-8 


28.0 


I . I 201 


15-4 


34-5 


I .1516 


18.95 


41.0 


1 .1846 


22.4 


47-5 


I . 2191 


25.9 


2$. I 


I . T206 


15-5 1 


34-6 


1.1521 


19.0 


41.1 


1.1851 


22.5 


47.6 


I . 2196 


25-0 


28.2 


I .1210 


15-55 


34-7 


I . 1525 


19. 1 


41 .2 


I .1856 


22.5 


47-7 


I .2201 


26.0 


28.3 


I.I2IS 


15.6 


34-8 


1.1531 


19.1 


41-3 


l.l85i 


22.6 


47-8 


I . 2207 


26.0 


28.4 


I . 1220 


15-7 


34-9 


1-1536 


19-2 


41 .4 


1.1855 


22.65 


47.9 


I . 2212 


26.1 


28.5 


I .1225 


lS-7 


35-0 


1-1541 


19.2 


41.5 


1.1872 


22.7 


48.0 


I .2218 


26.1 


28.6 


I. 1229 


15-8 


35-1 


1.1546 


19.3 


41.5 


1.1877 


22.75 


48.1 


I .2223 


26.2 


28.7 


I. 1234 


15.8 


35-2 


I - 1551 


19-3 


41-7 


1.1S82 


22.8 


4.S.2 


I . 2229 


26.2 


28.8 


I. 1239 


lS-9 


3S-3 


1-1556 


19.4 


41.8 


I. 1887 


22.9 


48.3 


I .2234 


26.3 


28.9 


I .1244 


15-9 


35-4 


1 .1561 


19.4 


41.9 


1 . 1892 


22.9 


48.4 


I .2240 


26.3s 


29.0 


1.1248 


16-0 


35-5 


1 - 1565 


19. 5 


42.0 


I. 1898 


23.0 


48.5 


1.224s 


26.4 


29.1 


I.I253 


16-0 


35-6 


1-IS7I 


19-55 


42. I 


1.1903 


230 


48.6 


I .2250 


26.45 


29.2 


I.I2S8 


16.1 


35-7 


1.1575 


19.6 


42-2 


1.1908 


23-1 


48.7 


1.2255 


26.5 


29.3 


1. 1 263 


16-1 


35-8 


1.1581 


19-55 


42-3 


1.1913 


23.1 


48.8 


I .2251 


25.5 


20.4 


1. 1267 


16.2 


35-9 


1.1586 


19-7 


1 42.4 ! 1 . 1919 


23-2 


48-9 


I .2267 


26.6 


29. 5 


1 . 1272 


16.25 


36.0 


I-1591 


19.8 


42-5 


1.1924 


23-2 


49-0 


1.2272 


26.7 


29.6 


1.1277 


16.3 


36.1 


1.1596 


19.8 


42.6 


1.1929 


23-3 


49-1 


1.2278 


26.7 


29.7 


1.12S2 


16.4 


36.2 


I . 1601 


19.9 


42-7 


I. 1934 


23-3 


49-2 


1.2283 


25.8 


29.8 


1. 1 287 


16.4 


36.3 


1 . 1606 


19.9 


42.8 


1. 1940 


23-4 


49-3 


I . 2289 


26.8 


29-9 


I .1291 


16.5 


36-4 


I . 161 1 


20.0 


42.9 


I. 1945 


23-45 


49-4 


1.2294 


26.9 


30.0 


I .1296 


16. S 


36.5 


I . 1616 


20.0 


43-0 


1.1950 


23-5 


49-5 


1 . 2300 


26.9 


30.1 


I . 1301 


16.6 


36-6 


I .1621 


20. 1 


43 ■■ ; I -1955 


23-55 


49.6 


1.2305 


27.0 


30.2 


1. 1 306 


16.6 


36.7 


I .1626 


20.1 


43-2 


1 . 1961 


23-6 


49-7 


I . 23II 


27.0 


30 -3 


I .1311 


16.7 


36-8 


I . 1631 


20.2 


43-3 


I . 1965 


23-7 


49.8 


1.2316 


27.1 


30-4 


1.1315 


16.7 


36-9 


1.1636 


20.2 


43-4 


I.I97I 


23-7 


49-9 


1 .2322 


27.1 


30-S 


1 .1320 


16.8 


37.0 


1,1641 


20.3 


43-5 


I.IP76 


23.8 


50.0 


I .2327 


27.2 


30.6 


1.132s 


1 16.85 


37-1 


I .1646 


20.35 


43-6 


1 .1982 


23.8 


50-1 


1.2333 


27.2 


30.7 


I. 1330 


16.9 


37.2 


I . 1651 


20.4 


43-7 


1. 1987 


23-9 


50.2 


1.2338 


27-3 


30.8 


I. 1335 


17.0 


37-3 


I. 1556 


20.5 


43-8 


I. 1992 


23.9 


50.3 


I . 2344 


27-3 


30.9 


1. 1 340 


17.0 


37-4 


1.1661 


20.5 


43-9 


1 . 199S 


24.0 


SO. 4 


I . 2349 


27.4 


3I-0 


1.1344 


17-1 


37-S 


1.1666 


20.6 


44.0 


1 . iOJi 


24.0 


50.5 


1.2355 


27.4s 


3I-I 


1 . 1 349 


17-1 


37-6 


1 . 1671 


. 20.5 


44-1 


I . 2008 


24.1 


50.6 


1 .2361 


27-s 


31.2 


1-1354 


17-2 


37-7 


I . 1676 


20.7 


44-2 


I. 2013 


24.1 


5°-Z 


1.2355 


27-ss 


31-3 


1.1359 


17.2 


37-8 


1.1681 


20.7 


44-3 


I . 2019 


24.2 


50.8 


1-2372 


27-6 


31 -4 


1.1364 


17-3 


37-9 


1.1585 


20.8 


44-4 


I . 2024 


24.2 


SO. 9 


1-2377 


27.7 


31-5 


I . 1369 


17-3 


38.0 


I .1692 


20.8 


44- S 


1 . 2029 


24-3 


Sio 


I - 23.')3 


27-7 


31.6 


1.1374 


17-4 


38.1 


1.1697 


20.9 


44-6 


1.2035 


24-35 


SI. I 


1.2388 


27.8 


31-7 


I. 1378 


17-4 


38-2 


1 . 1702 


20. 9 


44.7 


I . 2040 


i 24-4 


51.2 


1-2394 


27.8 


31.8 


I. 1383 


17-S 


38.3 


1.1707 


21 .0 


44-8 


I .2045 


24-45 


51.3 


1.2399 


27.9 


31 .9 


I. 1388 


17-55 


38.4 


1.1712 


21.05 


44-9 


I . 2051 


24. 5 


Si-4 


1-2405 


27.9 


32.0 


I.l3y3 


17-6 


38.5 


1.1717 


21.1 


45 -0 


I .2056 


24.5 


Sl-S 


1 .2411 


28.0 


32.1 


1.1398 


17-7 


38.6 


1.1722 


21.15 


45-1 


z . 2061 


24.5 


51-6 


1 .2416 


28.0 


32.2 


1.1403 


17-7 


38.7 


1.1727 


21 . 2 


45.2 


I . 2067 


24.7 


SI. 7 


I .2422 


28.1 


32.3 


I .1408 


17.8 


38.8 


1.1732 


21.3 


45-3 


I .2072 


24.7 


51.8 


I . 2427 


23.1 


32-4 


I . 1412 


17-8 


38-9 


1-1737 


21.3 


45.4 


I. 2077 


24. ;i 


51.9 


1-2433 


2a. 2 


32-.'i 


1.1417 


17.9 


39-0 


1-1743 


21.4 


45 -S 


I .2083 


24.8 


52.0 


I . 2439 


28.2 



SUGAR AND SACCHARINE PRODUCTS. 



501 



RELATION OF BRIX, SPECIFIC GRAVITY, AND EAUME— (Co«/4«!(e(/). 



Per 




'6 
" 6 


Per 




0) p 


Per 






Per 






Cent 


Specific 


Sa 


Cent 


Specific 


?i 


Cent 


Specific 


Cent 


Specific 


of 


Gravity. 


p- 


of 


Gravity. 


tart 


of 


Gravity. 


of 


Gravity. 


Sugar. 




Sugar. 




Sugar. 




Sugar. 




521 


1 . 2444 


28.3 


S8.6 


I. 2816 


31.6 


65.1 


1.320S 


34-95 


71.6 


1 .3610 


38.2 


52-2 


1.2450 


28.3 


S8.7 


1.2822 


31-7 


6s. 2 


I -3211 


35-0 


71.7 


I .361J 


38-2 


S2-3 


I. 2455 


28.4 


58.8 


1.2S3S 


31-7 


65.3 


1.3217 


3S.OS 


71.8 


1-3623 


38.2 


S2.4 


I . 2461 


28.4 


S8.9 


1.2X54 


3'f 


65.4 


1.3223 


35 -I 


71-9 


1.3629 


38-3 


52-5 


1.2467 


28.5 


59.0 


I . 2840 


31.85 


65.5 


1.3229 


35-15 


72.0 


1-3635 


38.3 


52. 6 


1.2472 


28. 5 


59-1 


1.2845 


31.9 


65.6 


1.3235 


35-2 


72.1 


1-3642 


38.4 


52.7 


1.2478 


28.6 


59-2 


I. 2851 


31 .95 


65.7 


I .3241 


35-25 


72. 2 


I -3648 


38.4 


52.8 


1.2483 


28.65 


59.3 


1.2857 


32.0 


65.8 


1.3247 


35-3 1 


72.3 


1-3655 


38.5 


52.9 


I . 2489 


28.7 


59.4 


1.2863 


32.05 


65.9 


1.3253 


35-35 


72.4 


I. 3661 


38. S 


53-0 


I. 2495 


28.75 


59-5 


1.2869 


32.1 


66.0 


1 .3260 


35.4 


72. S 


1.3667 


38.6 


53-1 


I .2500 


28.8 


59.6 


1.2875 


32.1s 


66.1 


1 .3266 


35. 4 


72.6 


1 .3674 


38.6 


53.2 


I . 2506 


28.85 


59.7 


I .2881 


32.2 


66.2 


1.3272 


35. S 


72.7 


I .3680 


38.7 


53.3 


I . 2512 


28.9 


59-8 


I .2887 


32.3 


66.3 


1.3278 


3S-5 


72.8 


1.3687 


38.7 


53-4 


1.2517 


28.9 


50-9 


I .2893 


32.3 


66.4 


1.328s 


3S-6 


72-9 


'-3693 


38.8 


53-5 


1.2523 


29.0 


60.0 


I .2898 


32.4 


66.5 


1.3291 


35-6 


73-0 


1-3699 


38.8 


53.6 


1.2529 


29.1 


60. 1 


1.2904 


32.4 


66.6 


1.3297 


35-7 


73-1 


1.3705 


38.9 


53-7 


1.2534 


29.1 


60. 2 


I . 2910 


32.5 


66.7 


1.3303 


35-7 


73-2 


1-3712 


38.9 


53.8 


1.2540 


29.2 


60.3 


I . 2916 


32.5 


66.8 


1.3309 


3S-8 


73.3 


1-3719 


39-0 


53.9 


1.2546 


29.2 


60.4 


I . 2922 


32.6 


66.9 


1.331S 


35-8 


73.4 


1-3725 


390 


54. 


1.2551 


29.3 


60.5 


I . 2928 


32.6 


67.0 


1.3322 


35.9 


73. 5 


1-3732 


39-1 


54.1 


I .2557 


29-3 


60.6 


1.2934 


32.7 


67.1 


1.3327 


35-9 


73. 6 


1.3738 


39-1 


54-2 


1.2563 


29.4 


60.7 


I . 2940 


32.7 


67.2 


1.3334 


36.0 


73-7 


1.3745 


39-2 


54-3 


1.2568 


29.4 


60.8 


1 . 2946 


32.8 


67.3 


1.3340 


36.0 


73.8 


1-3751 


39-2 


54-4 


1.2574 


29.; 


60.9 


I .2952 


32.8 


67.4 


1.3346 


36.1 


73.9 


1-3757 


39-3 


54.5 


1.2580 


29.5 


61 .0 


1.2958 


32.9 


67. S 


1.3352 


36.1 


74-0 


1.3764 


39-3 


54.6 


1.2585 


29.6 


61. 1 


1.2964 


32.9 


67.6 


1.3359 


36. 2 


74-1 


1.3770 


39-4 


^*-l 


1.2591 


29.6 


61.2 


I .2970 


33.0 


67.7 


1.3365 


36. 2 


74-2 


1.3777 


39-4 


S4.8 


1.2597 


29.7 


61.3 


1.2975 


33.0 


67.8 


I. 3371 


36.3 


74-3 


1.3783 


39-5 


54-9 


I . 2602 


29.7 


61.4 


I . 2981 


33.1 


67 -9 


1 .3377 


36.3 


74-4 


1-3790 


39-5 


55.0 


1 . 2608 


29.8 


61. S 


1.2987 


33.1 


68.0 


1.3384 


36.4 1 


74-5 


1-3796 


39-6 


55.1 


I .2614 


29.8 


61.6 


1.2993 


33.2 


68.1 


1.3390 


36.4 


74-6 


1-3803 


39-6 


SS.2 


I . 2620 


29.9 


61.7 


I .2999 


33-2 


68.2 


1 .3396 


36.5 


74.7 


I -3809 


39-7 


55-3 


I . 2625 


29.9 


61 .8 


I -3005 


33-3 


68.3 


1.3402 


36. 5 


74. 8 


I. 3816 


39-7 


55-4 


I . 2631 


30.0 


61 .9 


I .301I 


33.3 


68.4 


I . 3408 


36.6 


74.9 


I .3822 


39-8 


55-5 


1.2637 


30.05 


62.0 


1.3017 


33-4 


68.5 


I.34IS 


36.6 


75.0 


1.382S 


39-8 


55.6 


I .2642 


30.1 


62.1 


I .3023 


33.4 


68.6 


1.3421 


36.7 


75-1 


1-3835 


39-9 


55-7 


1.2648 


30.15 


62.2 


1.3029 


335 


68.7 


1-3427 


36.7 


7S-2 


I .3S42 


39-9 


55.8 


1.2654 


30.2 


62.3 


1.3035 


33-5 


68.8 


1 -3433 


36.8 ' 


75-3 


1-3848 


40.0 


55-9 


1.2660 


30.2s 


62.4 


I . 3040 


33.6 


68.9 


1.3440 


36.8 


75-4 


1-3855 


40.0 


56.0 


I .2665 


30.3 


62.5 


1.3047 


33.6 


69.0 


1.3446 


36.9 


75-5 


I. 3861 


40. 1 


56.1 


I .2671 


30.4 


62.6 


I. 3053 


33.7 


69. 1 


1.34S2 


36.9 


7S-6 


1.3868 


40.1 


56.2 


1.2677 


30.4 


62.7 


I .3059 


33.7 


69. 2 


1-3458 


37.0 


75-7 


1-3874 


40.2 


56.3 


1.2683 


30.5 


62. u 


I .3065 


33.8 


69 3 


1.3465 


37.0 


7S.8 


1.38S0 


40.2 


56.4 


I .2688 


30. 5 


62 .9 


I. 3071 


33.8 


69.4 


1.3471 


37.1 


75-9 


1.3887 


40. J 


56.5 


I .2694 


30.6 


63.0 


1.3077 


33-9 


69.5 


1.3477 


37-1 


76.0 


1-3894 


40.3 


S6.6 


1.2700 


30.6 


63. t 


I .3083 


33-9 


69.6 


1.3484 


37-2 


76.1 


1.390= 


40.4 


56.7 


1 . 2706 


30.7 


63.2 


. I .3089 


34.0 


69.7 


I - 3490 


37-2 


76.2 


1.3907 


40.4 


56.8 


I. 2712 


30.7 


63.3 


1.309s 


34.0 


69.8 


1.3496 


37-3 


76.3 


1-3913 


40.5 


56.9 


I .2717 


30.8 


63.4 


I . 3101 


34.1 


69.9 


1.3502 


37-3 


76.4 


1-3920 


40. s 


57. 


1.2723 


30.8 


63.5 


1.3107 


34-1 


70.0 


1.3509 


37-4 


76-S 


1.3926 


40.6 


57-1 


1.2729 


30.9 


63.6 


I .3113 


34.2 


70. I 


1.3515 


37.4 


76.6 


1.3933 


40.6 


57.2 


1.273s 


30.9 


63.7 


I.3119 


34.2 


70.2 


I.3S2I 


37-5 


76.7 


1-3940 


40.7 


57-3 


1.2740 


31 -o 


63.8 


I .3126 


34-3 


70.3 


1.3528 


37-5 


76.8 


1.3946 


40.7 


57-4 


1.2746 


31. 


63.9 


1.3132 


34.3 


70.4 


1.3534 


37-6 


76.9 


1.3953 


40.8 


57. 5 


1.2752 


31. 1 


64.0 


1.3138 


34.4 


70.5 


1.3540 


37-6 


77-0 


I .3959 


40.8 


57.6 


1.2758 


31. 1 


64. 1 


I .3144 


34.4 


70.6 


1.3546 


37-7 


77-1 


I .3966 


40.8 


57-7 


1.2764 


31-2 


64.2 


1.3150 


34-5 


70.7 


1..3S53 


37-7 


77-2 


1.3972 


40.9 


57.8 


I .2769 


31.2 


64.3 


I .3156 


345 


70;8 


1.3SS9 


37-8 


77-3 


I -3979 


41.0 


57.9 


I .2775 


31.3 


64.4 


I .3162 


34.6 


70.9 


1-3565 


37-8 


77-4 


I -398(1 


41.0 


58.0 


I .2781 


31.3 


64.5 


I. 3168 


34.6 


71.0 


1.3572 


37-9 


77-5 


1 -39J^ 


41.0 


58.1 


1-2787 


31.4 


64.6 


I. 3174 


34.7 


71. I 


1.3578 


37.9 


77.6 


1 .3999 


41.1 


58.2 


1.2793 


31.4 


64.7 


1 . 3 1 80 


34.7 


71.2 


1.3585 


38.0 


77.7 


I .4005 


41. 1 


58. 3 


1.2799 


31. S 


64.8 


1.31SO 


34.8 


71.3 


1.3S9I 


38.0 


77.8 


I . 40 1 2 


41.2 


S8.4 


I .2804 


31-5 


64.9 


I .3192 


34.8 


71.4 


1.3S97 


38.1 


77.9 


1.4019 


41.2 


58.5 


I . 2S10 


31.6 


65.0 


1.3198 


34.9 


1 71.5 


1.3604 


38.1 


78.0 


1.4025 


41-3 



S02 



FOOD INSPECTION AND ANALYSIS. 



RELATION OF 


BRIX 


, SPECIFIC GR.WITY, AND '&.\\5M.Y.— {Concluded). 


Per 






Per 




I- 

tir! 


Per 




■0 


Per 






Cent 


Specific 


Cent 


Specific 


Cent 


Specific 


hcrt 

turn 


Cent 


Specific 




of 


Gravity. 


of 


Gravity. 


of 


Gravity. 


of 


Gravity. 


Sugar. 




Sugar. 




Sugar. 




or 


Sugar- 




Q™ 


78.1 


I .4032 


41-3 


80.1 


1.4165 


42.3 


82.1 


1.4300 


43-3 


84-1 


I -4437 


44.2 


78.2 


1.4030 


41 .4 


80.2 


I. 4172 


42.3 


82.2 


1.4307 


43.3 


84-2 


I .4443 


44-3 


78.3 


I -4045 


41.4 


80.3 


I -4170 


42.4 


82.3 


I. 4314 


43-4 


84-3 


1.4450 


44.3 


78.4 


1.4052 


41S 


80.4 


I. 4185 


42.4 


82.4 


1.4320 


43.4 


84-4 


1-4457 


44-3 


78. s 


1.4058 


41-5 


80.5 


I. 4102 


42.5 


82.5 


1-4327 


43-5 


84-5 


1-4464 


44-4 


78.6 


I .4065 


41.6 


80.6 


1 .4109 


42.5 


82.6 


1-4334 


43-5 


84-6 


I -4471 


44-4 


78.7 


I .4072 


41 . 6 


80.7 


1 .4205 


42.6 


82.7 


1. 4341 


43.5 


84-7 


1-4478 


44.5 


78.8 


I .4078 


41 -7 


80.8 


I .4212 


42.6 


82.8 


1.4348 


43.6 


84-8 


I -4485 


44-5 


78.9 


I .4085 


41-7 


80.0 


1.4219 


42.7 


82.9 


I -4354 


43.6- 


84-9 


1-4402 


44-6 


70. 


1.4002 


41.8 


81.0 


1 .4226 


42.7 


83.0 


1-4361 


43-7 


85-0 


I -440S 


44-6 


70.1 


1.409S 


41.8 


8i.i 


1.4232 


42.8 


83.1 


1.436S 


43.7 


85.. 


I -450s 


44-7 


70- 2 


I .4105 


41.0 


81.2 


1.4230 


42.8 


83.2 


1.4375 


43.8 


85.2 


I. 45 I 2 


44.7 


70-3 


1 .4112 


41.0 


81.3 


1.4246 


42.9 


83.3 


1.4382 


43.8 


85.3 


I .4519 


44-8 


70 4 


1.4110 


42.0 


81 .4 


1.4253 


42.9 


83.4 


1.4388 


43.9 


85-4 


1.4526 


44-8 


70S 


1.4125 


42.0 


81. s 


1.4250 


43-0 


83. 5 


I -4395 


43-9 


85-5 


1.4533 


44-9 


70.6 


I. 4132 


42.1 


81.6 


I .4266 


43 


8?.6 


I .4402 


44 


8s. 6 


I .4540 


44 


70. 7 


I. 4138 


42.1 


81.7 


1.4273 


43.1 


83.7 


1.4400 


44 


8s-7 


1.4547 


45-0 


70 8 


1.414s 


42.2 


81.8 


I .4280 


43.1 


83.8 


I .4416 


44-1 


85.8 


I .4554 


450 


70 


I. 4152 


42.2 


81.9 


1.4287 


43.2 


83.0 


1.4423 


44-1 


85.0 


1.4561 


45-1 


80.0 


1.4158 


42.2 


82.0 


1.4203 


43-2 


84.0 


1.4430 


44-2 


86.0 


1.4568 


45.1 



polarizing in a loo-mm. tube (half the standard length) and multiplying 
the reading by 2. The clarifier best adapted as a rule for molasses and 
golden syrup is subacetate of lead.* 

The Process. — The normal weight, 26.048 grams, of the molasses or 
syrup is dissolved in water in a loo-cc. flask, and in the case of molasses and 
"golden," or "drip" syrup, sufficient subacetate of lead solution is added 
to precipitate the coloring matter. From 5 to 10 cc. of the clarifier 
usually suffice. The flask is then filled to the mark with water and the 
contents shaken thoroughly and filtered. If on account of air bubbles 
it is difficult to make up to the mark, the bubbles may usually be dis- 
pelled by a drop of ether. With maple syrup no clarifier is, as a rule, 
necessary, though sometimes alumina cream is helpful. With a very 
dark-colored molasses it is sometimes best to add both the subacetate 
and the alumina cream before making up to the mark, and in e-xtreme 
cases (though rarely with the grades of molasses used as food) it is neces- 
sary, after the ordinar}' filtration, to pass through from 5 to 6 grams of 
powdered, dried bone charcoal. f 

An excess of subacetate of lead should be avoided on account of the 
possibility of the filtrate becoming turbid through the formation of lead 
carbonate by exposure to the air. A drop of acetic acid will nearly always 

* Alumina cream, p. 482, and bone black, or animal char, are also useful, 
t The treatment with bone char should be used only as a last resort, as, on account of 
slight absorption of sugar, observed readings are from 0.4° to 0.5° too low. 



SUG/IR AND SACCHARINE PRODUCTS. S°i 

clear the solution, if the turbidity is due to carbonate. If cloudiness in 
the filtrate persists, weigh out a fresh portion of the sample, dilute, and 
add first the lead subacetate solution, and afterwards enough of a strong 
solution of sodium sulphate or common salt to precipitate the excess of 
lead; then fill to the mark and filter. Polarize, and conduct the inver- 
sion as directed on p. 483, using, however, a loo-mm. tube, and multi- 
plying the reading by 2, both direct and invert.* Use Clerget's formula 
for calculation of the sucrose. 

For medium- or light-colored grades of molasses, which yield but 
a small precipitate with lead subacetate, the above method of simple 
polarization, both direct and invert, gives results sufficiently accurate for 
ordinary work. For dark-colored, or "black-strap" molasses, or wherever 
extreme accuracy is required, the double dilution method of Wiley should 
be employed, which makes due allowance for the volume of the pre- 
cipitate. 

Double Dilution Metliod.-\ — Take half the normal weight of the sample 
and make up the solution to 100 cc, using the appropriate clarifier. Take 
the normal weight of the sample and make up a second solution with the 
clarifier to 100 cc. Filter and obtain direct polariscopic readings of 
both solutions. Invert each in the usual manner and obtain the invert 
reading of the two. 

The true direct polarization of the sample is the product of the two 
direct readings divided by their difference. The true invert polariza- 
tion is tlie product of the two invert readings divided by their difference. 

Determination of Raffinose in Beet Sugar Molasses. — For the deter- 
mination of sucrose and raffinose when present in the same solution, use 
the following formulas of Clerget: | 

C- 0.493a 

Sucrose = • (i) 

0.827 ^ ' 

and 

a-S 
Raffinose = ^ — ^r~, (2) 

1.85' '' ^ 

where a = direct reading, C = the algebraic sum of the direct and invert 
reading, and 5= per cent of sucrose. 

* The short tube (loo mm.) is preferred for polarizing molasses, not only on account of 
the more or less deep color of the clarified solution, but also because a molasses sample con- 
taining considerable commercial glucose would not read within the scale limits, if the 200-mm. 
tube were employed. 

t Wiley and Elwell, Analyst, i8g6, 21, p. 184. 

J Spencer, Handbook for Chemists of Beet Sugar Houses and Seed-culture Farms. 



504 FOOD INSPECTION AND ANALYSIS. 

DavoU * recommends for purposes of clarification of the molasses the 
use of powdered zinc after inversion of the molasses sample according to 
Clerget's method. He adds i gram of the zinc to the sample after in- 
version while at the temperature of 69° C, allowing it to act for three to 
four minutes at that temperature, after which he cools and filters, with 
the production of an almost colorless solution. 

Determination of Reducing Sugar. — {Estimated as Dextrose.) — Dilute 
5 grams of molasses or syrup with water in a loo-cc. graduated flask, 
using 2 to 5 cc. of subacetate of lead solution. Make up to 100 cc, 
filter, take an aliquot part of the filtrate (25 to 50 cc.) and make this 
up to 100 cc, the amount taken being such that, when diluted, the solu- 
tion will contain not more than ^% of dextrose. If lead subacetate has 
been used to clarify, add to the aliquot part taken and before dilution, 
enough sodium sulphate to precipitate the excess of lead, then filter 
and make up to the 100 cc. mark. 

Determine the reducing sugar in this solution by either volumetric 
or gravimetric Fehling processes. 

U. S. Standard Molasses is molasses containing not more than 25% 
of water, nor more than 5% of ash. 

Adulteration of Molasses and Syrups. — A common adulterant of all 
these products is commercial glucose. From its water-white color and 
inert sweetness, no less than from its cheapness, it forms an admirable 
aduherant for dark-colored or low-grade molasses and syrups, counter- 
acting to a great extent by its smoothness the strong and often disagree- 
able taste of the inferior products with which it is mixed. Thus a grade 
of molasses too cheap to be ordinarily used for food purposes can be 
made to assume the appearance, and to some extent the taste, of the 
higher-priced and light-colored grades, by admi.xture with commercial 
glucose. 

Tin salts are also used to improve the color of low-grade or dark 
molasses, and bleaching agents, such as sulphurous acid, are occasionally 
employed. Copper is sometimes found, due to utensils or vessels used 
in processes of manufacture. 

Lead may occur in maple syrup, due to the leaden plugs or spigots 
through which the sap is sometimes drawn from the trees. 

Detection and Determination of Commercial Glucose. f — From the 
direct polarization of a normal solution of molasses or syrup the presence 

* Jour. Am. Chem. Soc, 25 (1903), p. 1019. 
t Leach, ibid., p. 982. 



SUGAR AND SACCHARINE PRODUCTS. 50S 

or absence of commercial glucose can usually be established. The direct 
polarization of a normal solution of pure molasses should not be much in 
excess of 50° on the Soleil-Ventzke scale, while a pure, dark-colored molas- 
ses should polarize well under 40°. Golden syrup and maple syrup 
read higher than molasses, and a normal solution of pure maple syrup 
may have a direct polarization as high as 65°, being more often than not 
above 60°. 

An excessively high direct polarization is at once an indication of 
the presence of commercial glucose, while an invert reading at ordinary 
room temperature to the right of the zero-point is an almost positive 
proof of its presence in either of the above products. 

The optically active constituents of commercial glucose, viz., dextrin, 
maltose, and dextrose, are present in such varying amounts, that it is 
impossible to determine accurately the exact amount of this adulterant 
in complex saccharine products which themselves contain components 
common to glucose. Its approximate amount can, however, be very 
satisfactorily estimated in molasses and syrups by the use of the follow- 
ing formula: 

^_ (a-5)ioo ^ 
175 ' 

where G = per cent of commercial glucose, a = direct polarization, and 
5 = per cent of cane sugar previously obtained from the Clerget formula 
(p. 483). A large amount of invert sugar present affects the accuracy 
of this formula. It is especially applicable to maple syrup, wherein the 
per cent of invert sugar is small, but may be applied also to molasses 
and golden syrup, wherein the amount of invert sugar is not so large 
but that results may be obtained generally within 2 or 3% of the 
truth.f 

In saccharine products containing considerable invert sugar the 
method described on page 514 should be used. 

* Leach, U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 48. 

t The grade of glucose commonly employed by molasses and syrup manufacturers for 
admixture with their products, is the 42°-Be. variety. A grade of greater density could evi- 
dently not be used directly, since it would not readily flow. Indeed this grade (42° Be.) 
is sometimes thinned by water before mixing with the thinner syrups. The factor 175 is the 
one selected, because this is about the maximum polarization of the 42°-Be. grade, and it 
is right to give the benefit of any reasonable doubt to the manufacturer. 

For the sake of greater precision the result might well be expressed "in terms of com- 
mercial glucose polarizing at 175°." 



5o6 



FOOD INSPECTION AND /IN /I LYSIS. 



TYPICAL ANALYSES OF MOLASSES AND SYRUPS ADULTERATED WITH 

COMMERCIAL GLUCOSE. 



Polarization. 












Per Cent 
Sucrose 
(Clcrget's 
Formula). 


III 


Commercial 
Glucose 
(Leach's 
Formula). 


e 

'0 


(5 


> 


2 

N 
H=5 


62 


+36-3 


18° 


19 


30 -°3 


24.6 


29.36 


98.7 


+ 71-9 


18° 


19.9 


27.62 


45-0 


27.98 


109.7 


+ 90 


17" 


14.5 


33-11 


S4-4 


22.02 


73-5 


+39.8 


18° 


25 


31.61 


27.7 


23-67 


109.4 


+87.6 


17° 


16.9 


33-44 


52.8 


24.48 


143.6 


+ 136.0 


18.4° 


5-6 


38-17 


78-5 


21.52 


76.3 


+ 7-6 


18.6° 


SI 


i°-55 


14.4 


31-91 


77-9 


+ 24 


19° 


40.1 




21.6 


23-44 


87. 


+ 30.6 


22.4" 


42-5 


16.90 


25.4 


28.80 



<: 



(a) Molasses 

W " 

W " 

(a) Golden drip syrup 
(6) " " 
(c) " " 

(o) Maple s\Tup 

W " ■" 

W " " 



3-83 

3-53 



67 
■94 

-51 
.00 
.65 

.08 



Determination of Dextrin. — Accor(iing to Beckman's method a 
weighed amount of the honey or molasses is diUited with an equal volume 
of water and from ten to twelve times its volume of methyl alcohol is 
added. The precipitated dextrin is collected in a tared filter and thor- 
oughly washed ■with methyl alcohol, after which it is dried and weighed. 

Reduction of Saccharine Products to an Ash for Mineral Analysis, 
— If a considerable quantity of molasses, syrup, or other saccharine sub- 
stance is to be burnt to an ash, it is both tedious and annoying to ignite 
directly, by reason of the excessive swelling and frothing of such substances 
during ignition. Small quantities of molasses, syrup, or honey may with 
care be reduced to an ash by the method described on page 481. 

If a readily controlled electric current is available, it may be utilized 
as follows:* Mix 100 grams of molasses, syrup, or other saccharine 
solution, which should be evaporated to syrupy consistency if not already 
such, •with about 35 grams of concentrated sulphuric acid in a large 
porcelain evaporating-dish. An electric current is then passed through 
it while stirring, by placing one platinum electrode in the bottom of the 
dish near one side and attaching the other to the lower end of the glass 
rod, \d\\i which the contents are stirred. Begin with a current of about 
I ampere and gradually increase to 4.t In from ten to fifteen minutes 

* Leach, 32d .\n. Rept. Mass. State Board of Health (1900), p. 653. Reprint, p. 37. 
This method is preferred to the ordinary method of heating vdih sulphuric acid, especially 
in case of molasses, because, if properly manipulated, it so quietly comes into the form of a 
very finely divided char or powder, especially adapted for subsequent quick ignition. 

t Modified from method of Budde and Schou for determining nitrogen electrolytically. 
Ztschr. anal. Chem., 38 (1899), p. 345. 



SUGAR AND SACCHARINE PRODUCTS. 507 

the mass is reduced to a fine, dry char, which may then be readily burnt 
to a white ash in the original dish over a free flame or in a muffle. 

Or, 100 grams of the molasses or syrupy solution to be ashed may 
be first evaporated to dryness and afterward inixed with from 10 to 20 cc. 
of concentrated sulphuric acid in a porcelain evaporating-dish, or if the 
substance to be ashed be a dry sugar or confectioner}^, 20 grams are 
mixed with the above amount of acid. Heat is gently applied by means 
of the gas flame till the swelling and frothing have ceased, which usually 
requires only a few minutes. The final ignition is then accomplished 
in the usual manner, nitric acid being added if necessary to completely 
destroy the organic matter. 

Determination of Tin in Molasses. — Fuse the ash from a weighed 
portion of the sample with sodium hydroxide in a silver crucible, dis- 
solve in water, and acidulate with hydrochloric acid; filter and precipi- 
tate the tin from tliis solution with hydrogen sulphide; wash the pre- 
cipitate on a filter and dissolve it in an excess of ammonium sulphide. 
Filter this solution into a tared platinum dish, and deposit the tin directly 
in the dish by electrolysis, using a current of 0.05 ampere and the appa- 
ratus described on page 493. 

Distinction between Invert Sugar, Maltose, and Lactose.* — All these 
sugars reduce Feliling's solution. Dextrose and Icvulose (invert sugar) 
when boiled with Barfoed's copper acetate solution (14 grams cr}'stal- 
lized copper acetate and 5 cc. acetic acid in 200 cc. water) will form 
a precipitate of cuprous oxide, while neither maltose nor lactose vnll 
do this. The solution, which has thus been tested for invert sugar and 
found to be free, or the filtrate from the cuprous oxide precipitate, is 
treated with an excess of basic lead acetate, filtered, and to the filtrate 
is added an excess of sodium sulphate solution to precipitate the lead. 
The solution is again filtered and treated with copper sulphate solution, 
if not already blue. It is then made alkaline with sodium hydroxide 
and heated to boiling. A red precipitate of cuprous oxide at this stage 
indicates either lactose or maltose or both. 

A solution of the sugar, made strongly ammoniacal, is then mixed 
with alkaline bismuth solution f and the container is set in a water- 
bath at 60° C. Maltose soon reduces the bismuth, but lactose does not. 

To test for lactose, add strong nitric acid to the solid sugar residue 

* Bartley and Mayer, Merck's Report, 12 (1903), p. 100. 

t This reagent is prepared as follows; Bismuth subnitrate, 2 grams; Rochelle salt, 4 
grams; sodium hydroxide, 8 grams; dissolved in 100 cc. of water by the aid of heat. 



5o8 FOOD INSPECTION /1ND ANALYSIS. 

and warm gently till red fumes come off. Then set the container in hot 
water and cool gradually. Crystals of mucic acid appear after a time 
if any appreciable amount of lactose be 'present. 

Determination of Lactose or Maltose. — Either sugar, if in solution 
free from other reducing sugars, may be determined by the volumetric 
Fehling method (p. 486) or by the Defren method, using the table on 
page 490. 

For the determination of maltose in commercial glucose, see page 509. 

Estimation of Cane Sugar and Dextrose in Mixtures. — Obtain true 
direct and invert readings of a normal solution of the mixture. Deter- 
mine the per cent of sucrose by Clerget's formula (p. 483). This figure 
represents the right-handed rotation due to sucrose. Subtracting this 
from the direct polarization, the difference represents the right-handed 
rotation due to dextrose. The specific rotary power of sucrose is 66.5 
and that of dextrose 52.3. 

Calling d the percentage of dextrose and R' the right-handed rota- 
tion due to dextrose as above obtained, if the Soleil-Ventzke scale is used, 

66.s:52.3 = (f:i?', 
whence 

66. 5i?' 



d- 



52-3 



Determination of Levulose.* — On page 484 attention was called to 
the variation in the rotar}' power of levulose with the temperature. This 
variation is constant, and i gram of levulose in 100 cc. of water produces 
a decrease in left-handed reading of 0.0357° on the cane sugar (Ventzke) 
scale for each 1° C. increase in temperature. Therefore, the weight 
of levulose present in a given solution can be calculated from the polari- 
scopic readings at two temperatures, using a water-jacketed tube, as 
described on page 515. 

R-R' 
"0.0357 (/-/')' 

where Z,= weight of levulose, 

i? = reading at higher temperature t, 
i?' = reading at lower temperature /'. 

The percentage of levulose present in the solution may readily be cal- 
culated as follows: 

* Wiley, Agric. Anal., p. 272. 



SUGAR /tND SACCHARINE PRODUCTS. 509 

K L' = percentage of levulose, 

i = weight of levulose in solution, 
P7 = weight of sugar sample made up to 100 cc, 
_LXioo 

In a normal solution 1^ = 26.048. 

Analysis of Commercial Glucose. — Wiley * has worked out a method 
for calculating the percentage of dextrin, maltose, and dextrose present 
in commercial glucose, based on the specific rotary power of these sub- 
stances and on the relative reducing power of maltose and dextrose. 
To apply this method, the operator, if he has a polariscope reading in 
sugar scale degrees, must ascertain the equivalent readings in angular 
degrees from the table on page 478, and calculate the specific rotary power 

1 00a 
in each case from the formula («)£> = — j-, page 479. 

Thus, if he possesses a Schmidt and Haensch instrument, he should 
multiply the true reading, as obtained on that instrument, with a normal 
solution of the given sugar or mixture, by the factor 0.3468, to convert 
the reading into circular degrees from which to figure the specific rotary 
power as above. 

The specific rotary power of dextrin is fixed at 193, that of maltose 
138, and that of dextrose at 53. 

Then if P = total polarization of the mixture in terms of specific 
rotary power, (/ = per cent dextrose, w = per cent maltose, and (/'=per 
cent dextrin, 

P = 53(i+i38»f+i93(i' (i) 

The value of P is obtained from observation and calculation as above 
described on a known solution of the sample, say 10 grams in 100 cc. 
The reducing sugars, maltose and dextrose, are then removed, prefer- 
ably by oxidation with cyanide of mercury, as follows : | 

Prepare the reagent by dissolving 120 grams mercuric cyanide and 
120 grams sodium hydroxide in water, mixing the two solutions, and 
making up to 1,000 cc. Remove any precipitate that may gather by 
filtration. 

Make a solution of 10 grams of the glucose sample in 100 cc. and 
take 10 cc. of this solution in a so-cc. graduated flask. Add sufficient 

* Chem. News, 46, p. 175; Agric. Anal., 3, pp. 288-290. 
t Wiley, Agric. Analysis, p. 290. 



5IO FOOD INSPECTION AND ANALYSIS. 

mercuric cyanide solution to have an excess of reagent after the oxidation 
(from 20 to 25 cc), and boil for three minutes under a hood with a good 
draft- Cool and neutralize the alkali with concentrated hydrochloric 
acid, adding the latter till the brown color is discharged. By this method 
the optical activity of the maltose and dextrose is discharged, while that 
of the dextrin remains unaffected. From the polariscope reading cal- 
culate as above the specific rotary power of the dextrin (P'). Then 

^' = 193^^' (2) 

The reducing power on Fehling's solution of dextrose is to that of 
maltose as 100 is to 62. Whence, if i?= reducing sugar (reckoned as 
dextrose) we have 

R = d^o.(i2m (3) 

Subtracting equation (2) from equation (i) we have 

P-P' = 53^+i38m (4) 

Multiplying equation (3) by 53 and subtracting from equation (4), 

P-P' = 53(/+i38m, 

53 -^ = 53'^+ 32 -86^, 

P — P'- 53^ = 105. 14W (5) 

Therefore 

P-P'-53P ,,, 

m = ^^^, (6) 

105.14 ^ '' 

d=R— 0.62m, (7) 

• p, 

d' = — (8) 

193 

Determination of Dextrin in Commercial Glucose. — One volume of 
the sample is well shaken with about 10 volumes of 90% alcohol, and 
the precipitated dextrin" is separated by filtration through a tared filter, 
washed thoroughly with strong alcohol, dried at 100°, and weighed. 

Qualitative Tests for Commercial Glucose. — Several confirmatory 
chemical tests may be employed for commercial glucose, aside from 
the optical test with the polariscope. Thus a precipitate of dextrin 
by treatment of the sample with an excess of strong alcohol, in the absence 
of mineral salts insoluble in alcohol, is strongly indicative of commercial 
glucose. An excess of calcium sulphate in the ash also points strongly to 
the presence of glucose. 



SUG/1R AND SACCHARINE PRODUCTS. 511 

Arsenic in Commercial Glucose. — Like all products wherein commer- 
cial sulphuric acid is employed in its manufacture, glucose sometimes 
contains arsenic, though usually in minute traces. Arsenic is readily 
indicated, when present, by the Gutzeit test, conducted as follows: 2 
grams of the sample are introduced into a small Erlenmeyer flask of about 
100 cc. capacity, and diluted with 5 to 10 cc. of water. Scraps of arsenic- 
free, granulated zinc are then added. A small filter-paper is carefully 
folded smoothly around the bottom of a cork that loosely fits the mouth 
of the flask, and is moistened with a concentrated solution of mercuric 
chloride. From 6 to 8 cc. of arsenic-free concentrated hydrochloric * 
or sulphuric acid are then added to the flask, so as to produce rapid, but 
not too violent evolution of gas, and the cork is loosely inserted. 

After ten minutes the cork is removed, and, if a yellow stain is present 
on the filter, arsenic is indicated. The amount of arsenic present varies 
with the depth of color, and if a large amount is present the stain may 
be dark brown or even black. 

Sulphides interfere with the Gutzeit test, but are rarely present in 
commercial glucose. Unless sure of the purity of the reagents it is well 
to make a blank test thereon. In such a blank, the filter should be per- 
fectly white after ten minutes. 

The amount of arsenic may be roughly determined colorimetrically 
by the Gutzeit method. 

For more careful determination, employ the Marsh apparatus, into 
which the diluted glucose may be directly introduced without previous 
treatment. 

HONEY. 

Composition and Occurrence. — Honey is the saccharine product 
deposited by the bee (Apis, nielli fica) in the cells of honeycomb, which 
the insect forms out of wax secreted by its body. Honey has its source 
chiefly in the nectaries of flowers, from which the bees abstract it. The 
juices of ripe fruits and the sap of trees also furnish honey. During 
the secretion of the honey in the body of the bee, the sucrose, which forms 
the chief constituent of the fruit juice or nectar, becomes for the most 
part inverted, forming, in the honey, dextrose and levulose. 

The flavor of honey varies considerably according to its source. 
Besides water, the sugars, and mineral matters, pollen is usually present, 

* Hydrochloric acid is better than sulphuric acid, as the action is much more brisk with 
pure zinc. 



512 FOOD INSPECTION AND ANALYSIS. 

derived from the flowers, also as a rule a small quantity of wax, and 
nearly always appreciable amounts of various organic acids, such as 
formic. 

A large number of samples of genuine honey analyzed in 1897 for 
the Department of Inland Revenue, Canada (Bui. 47), showed th§ follow- 
ing variations: 

Direct polarization — 2.4 to — 19 

Invert " -10.2 " -28 

Sucrose (by Clerget) 0.5% " 7-64% 

Invert sugar 60.37% " 78-8% 

Water 12% " 33% 

Ash 0.03%" 0.50% 

The following are typical analyses of honey adulterated with cane 

sugar: 

A. B. c. 

D-irect polarization. .. . +34.7 +12 +1-2 

Invert " —24 —17.6 —21.5 

Temperature 14° 15° 19 -5° 

Sucrose (Clerget) 43-i6% 21.8% 17-07% 

Invert sugar 42.48% 60.03% 67.2% 

Water 42.42% 21.15% iS-56% 

Ash .11% 0.06% 

The following are typical analyses of honey adulterated with com- 
mercial glucose: 

A.* B. c. 

Direct polarization. . +147 +66.9 +101. 5 

Invert " .. +135.2 +61.9 + 99.0 

Temperature 18° 20° 22° 

Sucrose (Clerget) . ... 8 . 83% 3.76%, 0.0%, 

Invert sugar 46.18% 74.66% 49.87% 

Water iS-i9% 21.40%, 23.7% 

Ash 0.03% 

Analysis of Honey. — In the case of strained honey, stir with a rod 
till any separated sugars are evenly distributed throughout the mass, 
or, if the honey has become solidified wholly or in part by crystallization, 
use a gentle heat on a closed water-bath to restore it to fluid form. 

* Both commercial glucose and added cane sugar. 



SUG/IR AND SACCHARINE PRODUCTS. 513 

In the case of comb honey, cut with a knife across the top of the comb, 
if sealed, and separate completely from the comb by straining through 
a 40-mesh sieve. 

Water and Ash are determined as directed on page 498 in the case of 
molasses and syrup. 

For polarization of honey both direct and invert, proceed as directed 
on page 502 except that instead of subacetate of lead, alumina cream is 
employed for a clarifier, the reagent being added in excess before making 
up to the mark in the loo-cc. flask. On account of birotation, a drop 
or tvi^o of ammonia is added.* Aside from these precautions exactly the 
same method of procedure is adopted as in the case of molasses and 
syrup. 

Determination of Invert Sugar. — Weigh 5 grams of the sample into 
a loo-cc. graduated flask, dissolve in water, clarify with about 5 cc. of 
alumina cream, and make up to the loo-cc. mark. Filter and determine 
invert sugar in an aliquot part of the filtrate by cither volumetric or 
gravimetric Fchling processes. 

Adulteration of Honey. — The most common adulterants of honey 
are cane sugar and commercial glucose. Sometimes both are emploj'ed 
in the same sample. Gelatin is also said to be used. It appears to be 
a fact that bees may be made to feed upon cane syrup or commercial 
glucose, if these materials are placed in proximity to their hives, so that 
in some instances the adulterant may be supplied through the medium 
of the bee. Sophisticated honey is often put up in tumblers or jars con- 
taining pieces of honeycomb, so that presence of the comb is by no means 
proof of its purity. Sometimes the comb itself is artificial.t Comb- 
honey, sold in the frame as sealed by the bees, is never adulterated, except 
when the bees are fed upon glucose or cane sugar. 

Gelatin is indicated if a precipitate occurs in the diluted sample with 
a solution of tannic acid. 

A right-handed polarization of honey at once makes it suspicious. 
The author has never found a sample of genuine honey that polarized 
to the right of the zero-point, though cases are on record of pure right- 
handed honeys. Such are said to have been yielded from the exudation 
of certain pine trees, the honey from this source possessing notable quan- 

* Friihling, Zeits. offentl. Chemie, 4 (1898), p. 410. 

t A sample of alleged honey was purchased by one of the inspectors of the Food and 
Drug Department of the Mass. State Board of Health, put up in a glass jar with a large 
mass of honeycomb and a dead bee. No genuine honey was found, the mixture consist- 
ing of commercial glucose and cane sugar. Even the comb was artificial. 



514 FOOD INSPECTION AND ANALYSIS. 

titles of dextrin, which in normal honey is absent. A high right-handed 
rotation points either to cane sugar or to commercial glucose as adulter- 
ants. If, after inversion of the honey sample, the polarization is left- 
handed, the adulterant is undoubtedly cane sugar. If the polarization 
after inversion is still right-handed, commercial glucose is no doubt 
present. 

Notable amounts of calcium sulphate, when tested in the diluted 
honey, indicate commercial glucose. The test for calcium is made 
with ammonia and ammonium oxalate; that for sulphuric acid with 
hydrochloric acid and barium chloride in the usual manner. 

The presence of commercial glucose is strongly indicated if, on the 
addition of 3 or 4 volumes of strong alcohol to the honey, a precipitate 
of dextrin is found. Pure honey should show only a slight millcincss 
and no actual precipitate when thus treated. 

Determination of Commercial Glucose in Honey. — Except for rough 
work, the method described on page 505 for calculating the per cent of com- 
mercial glucose from the sucrose and from the direct polarization is not 
recommended for use with honey and other products wherein the invert 
sugar is so large as to considerably affect its accuracy. In this case, it 
is best after inversion to polarize the sample at 87° C, the temperature 
at which the reading due to invert sugar would be o. At this tempera- 
ture, any right-handed polarization can be accounted as due to commer- 
cial glucose. 

As in the case of molasses, the writer advocates assuming 175° as the 
direct polarization of the glucose used, this being about the maximum 
reading for a normal solution of 42°-Be. glucose. Lythgoe has shown 
that in polarizing at high temperatures samples of saccharine products 
containing commercial glucose, certain precautions have to be observed 
not necessary when cane or invert sugar are the only sugars present. 
Thus, a normal solution of glucose, when polarized at 87° C, has a lower 
reading than in the cold, the difference being doubtless due partly at 
least to the expansion of the liquid. Again, on subjecting a normal 
solution of glucose to inversion with acid, as in Clerget's process, and 
heating to 87° C, it will be found impossible to get a constant reading, 
but the reading will drop rapidly, due to a partial hydrolysis of the maltose 
or dextrin. 

In honey and other preparations containing much invert sugar and 
commercial glucose, it is best to proceed as follows: Obtain the direct 
reading, if desired, on a normal solution in the ordinary manner. For 



SUGAR AND SACCHARINE PRODUCTS. 5 '5 

the invert reading, weigh out a separate half-normal portion in a loo-cc. 
sugar-flask, dilute to about 70 cc. with water, add 7 cc. of hydrochloric 
acid (specific gravity 1.20), and heat in the regular manner to 68° C. 
Cool, add a few drops of phenolphthalein, and neutralize with sodium 
hydroxide. Add a few drops of dilute hydrochloric acid to discharge the 
pink color, then from 5 to 10 cc. of the appropriate clarifier (in the case 
of honey, alumina cream), cool again, and make up to the loo-cc. mark. 
Polarize in a 200-mm. jacketed tube at 87°, and multiply the reading 
by 2. The invert reading may be obtained on the same solution at 20°, 
if desired. Divide the true reading at 87° by 163 * and multiply the result 
by 100 for the percentage of commercial glucose in terms of glucose 
polarizing at 175°. See also Appendix, page 769. 

Polarization at the temperature of 87° can most readily be effected 
by the use of a water-jacketed tube, as shown in Fig. no. An all-metal 
tube, the interior of which is heavily gold-plated to avoid corrosion by 
acid, is preferable to one in which the inner tube is glass with a metal 
jacket, as in the latter leaky joints are liable to occur, due to uneven 
expansion. A tubulure is provided in the outer tube for a thermometer, 
so that the exact temperature may be noted. A tank of boiling water 
placed on a shelf above the polariscope is connected by rubber tubing 
with the jacketed tube as it rests in the polariscope, as shown in Fig. 
no. 

Beeswax. — The purity of beeswax is best established by determining 
its melting-point, its specific gravity, its saponification equivalent, and 
its refractometric reading. The melting-point of pure wax is about 
64° C, while that of parafiin, its chief adulterant, is from 52° to 55° C. 
Its saponification equivalent should be from 87.8 to 107, while that of 
paraffin is o. 

Method of Determining Specific Gravity of Beeswax.'f — Place a weighed 
rod of the wax, about i to 1.5 cm. long by 0.5 cm. diameter, in an accurately 
marked 50-cc. flask, and run in water from a burette till the water level 
reaches the mark. 50 cc. minus the burette reading represent the vol- 
ume occupied by the wax. The rod should be made to he flat on the 
bottom of the flask, so that the incoming water will force its ends against 
the sides and prevent the end from rising above the mark. The volume 

* The true polarization at 87° C. of a normal solution of glucose subjected to inversion 
and neutralization as above (but without the use of the clarifier), will be about 93% that 
of the direct polarization of the sample in the cold. Hence 175 Vo. 93 = 162. 7. 

■\ Bulletin 13, U. S. Department of Agriculture, Division of Chemistry, p. 842. 



5i6 



FOOD INSPECTION AND /IN A LYSIS. 



of the rod, divided by its weight, gives its specific gravity. The specific 
gravity of various mixtures of wax of 0.969 specific gravity and paraffin 
of 0.871 are given in the following table, prepared by Wagner, so that 

fl 




Fig. 1 10. — Apparatus for Polarizing at High Temperatures. 



from the specific gravity of the mixture the percentage of paraffin can be 
calculated : 



Wax 
(Percentage). 


Paraffin 
(Percentage). 


Specific 
Gravity. 


Wax 
(Percentage). 


Paraffin 
(Percentage). 


Specific 
Gravity. 


25 

5° 


100 

75 
5° 


.871 

•893 
.920 


11 
100 


25 

20 


.942 
.948 
.969 



The Refractometer Reading is most useful in establishing the purity 
of wax. Observations with this instrument are best made at 65° and 
great care should be taken in the case of the Zeiss butyro-refractometer 
"not to exceed this temperature, or injur)' to the instrument may result. 



SUG/tR AND SACCHARINE PRODUCTS. 517 

The Abb^ refractometer may be used with perfect safety and, when 
available, is to be preferred for the examination of beeswax. Many 
food laboratories are, however, not equipped with the Abbe, but nearly 
all find the butyro-refractometer indispensable. The latter instrument 
was primarily designed for such substances as butter and lard, so that the 
manufacturers did not intend it to be subjected to as high a temperature 
as 65°. They have, however, assured the author that if care be taken 
to bring the temperature very slowly and gradually to the required degree, 
65°, and to avoid also sudden -cooling, the cement that secures the prisms 
in place will not be appreciably affected; otherwise cracking or loosening 
of the cement would be liable to occur after a time. 

At 65° C. pure beeswax should have a reading on the butyro-refrac- 
tometer of 30 to 31.5,* while that of paraffin is from 11 to 14.5.! 

CONFECTIONERY. 

The composition of confectionery is more complex than that of the 
saccharine products hitherto considered. As a rule, cane sugar, or one 
of its products, as molasses, forms the basis of most of the confections. 
Commercial glucose is also a common ingredient, while a large variety 
of such materials as eggs, butter, chocolate, various flavoring extracts, 
spices, nuts, and fruits, enter into the composition of confectionery. 

U. S. Standard Candy is candy containing no terra alba, barj'tes, 
talc, chrome yellow, or other mineral substances or poisonous colors or 
flavors, or other ingredients injurious to health. 

Adulteration. — Of late the adulteration of confectionery has been 
held largely in check by the National Confectioners' Association of the 
United States, which has fixed high standards of purity, and has been 
very zealous in restricting the use of harmful adulterants. 

Commercial glucose is not regarded as an adulterant of confectionery 
by the above-named association and by but few of the state laws. On the 
contrary, any ingredient, other than color, that has no food value, may 
logically be considered as an adulterant. Under this head are included 
such substances as paraffin, as well as make-weight mineral matters, such 
as terra alba, talc, or calcium sulphate. 

Most of the actually harmful ingredients employed in confectionery 
have been inherent in the coloring matters, or in the alcohol or fusel oil 
used in the manufacture of brandy drops and allied confections. 

*«£» 1.4452 to 1.4463. t «z)> 1-4310 to I-4335- 



Si8 FOOD INSPECTION AND ANALYSIS. 

Colors in Confectionery. — A very wide range of colors is necessarily 
employed in the manufacture of confectioner}', and the almost endless 
variety of coal-tar dyes now available lend themselves most readily to 
the confectioner's needs. Elsewhere, under "colors," lists of injurious 
and non-injurious dyes are given as compiled by the National Confec- 
tioners' Association, though it is not always readily apparent how the lines 
are drawn. 

The tinctorial power of these dyes is so high that the actual amount 
of substance contained in a thin coating of the color on the outside of the 
candy is exceedingly small, so that it is doubtful whether serious cases of 
injury have ever arisen from their use. 

Such was not the case formerly, before the prevalence of the coal-tar 
dyes, when such poisonous mineral pigments as chromate of lead were 
frequently used. Only one or two instances of the use of lead chromate 
in candy have come to the author's attention within ten years, since more 
satisfactory and harmless yellow colors among the azo-dyes are now 
obtainable. 

Analysis of Confectionery. — The following have been submitted 
by the author as provisional methods of procedure for the A. O. A. C.:* 

(i) Products of Practically Uniform Composition Throughout. — 
(a) Lozenges and Other Pulverizable Products. — Grind in a mortar or 
mill to a fine powder. For total solids, weigh from 2 to 5 grams of the 
powdered sample in a tared platinum dish, and dry in a McGill oven 
to constant weight. 

For Ash, ignite the residue from total solids in the original dish, observ- 
ing the precautions given under sugar (p. 481), and m^olasses (p. 506). 

(b) Semi-plastic, Syrupy, or Pasty Products. — W;igh 50 grams of 
the sample into a 250-cc. graduated flask, mix thoroughly or dissolve, 
if soluble, in water, and fill to the mark. Be sure that the solution is 
uniform, or, if insoluble material is present, that it is evenly mixed by 
shaking before taking aliquot parts for the various determinations. For 
total solids and ash, measure 25 cc. of the above solution or mixture into 
a tared platinum dish, and proceed as directed under (a). 

(2) Confectionery in Layers or Sections of Different Composition. — 
When it is desired to examine the different portions separately, they 
should be separated mechanically with a knife, when possible, and treated 
as directed under (i). 



* U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 44. 



SUGAR AND SACCHARINE PRODUCTS. 519 

(3) Sugar-coated Fruit, Nuts, etc.— In case of a saccharine coating 
inclosing fruit, nuts, or any less readily soluble material, dissolve or 
wash off the exterior coating in water, which may, if desired, be evaporated 
to dryness for weighing, and proceed as in (i). 

(4) Candied or Sugared Fruits. — Proceed as in the examination of 
frui:s (Chapter XIX). 

Detection of Mineral Adulterants. — As in the case of molasses, a 
considerable quantity, say 100 grams, should be reduced to an ash for 
examination for mineral adulterants, such as talc, calcium sulphate, and 
iron oxide, which are detected by regular qualitative tests. 

Detection of Lead Chromate. — Fuse the ash in a porcelain crucible 
with a mixture of sodium carbonate and potassium chlorate, boil the 
fused residue with water, neutralize with acetic acid, filter, and treat the 
filtrate with barium chloride or lead acetate solution. A yellow pre- 
cipitate indicates a chromate. Treat the insoluble part of the fusion 
with nitric acid, and test for lead in the usual manner. 

If a drop of ammonium sulphide be applied to a piece of confectionery 
colored with lead chromate, it will produce a black coloration. 

Determination of Ether Extract. — The ether extract includes the fat 
derived from chocolate, eggs, or butter, as well as any paraffin present. 
Measure 25 cc. of the 20% solution (i) (J) (p. 518) into a very thin, 
readily frangible glass evaporating-shell (Hojjmeisier's Schdlchen), con- 
taining 5 to 7 grams of freshly ignited asbestos fiber; or, if impossible to 
thus obtain a uniform sample, weigh out 5 grams of the mixed, finely 
divided sample into a dish, and wash with water into the asbestos in the 
evaporating-shell, using, if necessary, a small portion of the asbestos 
fiber on a stirring- rod to transfer the last traces of the sample from dish 
to shell. Dry to constant weight at 100°, after which cool, wrap loosely 
in smooth paper, and crush into rather small fragments between the 
fingers, carefully transferring the pieces with the aid of a camcl's-hair 
brush to an extraction-tube, or to a Schleicher and Schull cartridge for 
fat extraction. Extract with anhydrous ether or with petroleum e'Jier in 
a continuous extraction apparatus for at least twenty-five hours. Trans- 
fer the solution to a tared flask, evaporate the ether, dry in an oven at 
100° C. to constant weight, and weigh. 

Determination of Paraffin. — Add to the ether extract in the flask, as 
above obtained, 10 cc. of 95% alcohol, and 2 cc. of i :i sodium hydroxide 
solution, connect the flask with a reflux condenser, and heat for an hour 
on the water-bath or until saponification is complete. Remove the con- 



S20 FOOD INSPECTION AND AN /t LYSIS. 

denser, and allow the flask to remain on the bath till the alcohol is evapo- 
rated off, and a dry residue is left. Treat the residue with about 40 cc. 
of water, and heat on the bath, with frequent shaking, till everything 
soluble is in solution. Wash into a separatory funnel, cool, and extract 
with four successive portions of petroleum ether, which are collected in 
a tared flask or capsule. Remove the petroleum ether by evaporation, and 
dry in the oven to constant weight. 

It should be noted that any phytosterol or cholesterol present in the 
fat would come down with the paraffin, but the amount would be so 
insignificant that, except in the most exacting work, it may be disregarded. 
The character of the final residue should, however, be confirmed by 
determining its melting-point and specific gravity, and by subjecting it 
to examination in the butyro-rcfractometer. The melting-point of par- 
affin is about 54.5° C; its specific gravity at 15.5° C. is from 0.868 to 0.915, 
and on the butjTo-refractometer the reading at 65° C. is from 11 to 14.5. 

Determination of Starch. — Measure gradually 25 cc. of a 20% aqueous 
solution or uniform mixture of the sample into a hardened filter or Gooch 
crucible, or transfer by washing 5 grams of the finely powdered substance 
to the filter or Gooch, and allow the residue on the filter to become air- 
dried. Extract with five successive portions of 10 cc. of ether, then 
wash with 150 cc. of 10% alcohol, and finally with 20 cc. of strong alcohol. 
Transfer the residue to a large flask and boil gently for four hours with 
200 cc. of water and 20 cc. of hydrochloric acid (specific gravity 1.125), 
the flask being provided with a reflux condenser. Cool, neutralize with 
sodium hydroxide, add 5 cc. of alumina cream, and make up the volume 
to 250 cc. with water. Filter and determine the dextrose in an aliquot 
part of the filtrate by any of the various Fehling methods. The weight 
of the dextrose multiplied by 0.9 gives the weight of the starch. 

Polarization of Confectionery. — As a clarifier use either alumina 
cream or subacetate of lead, according to the nature and opacity of the 
sample. Ordinarily alumina cream is best, but in dark-colored samples, 
or those in which molasses has been used, it is sometimes necessary to 
employ the subacetate. When starch is absent, and the sample is practi- 
cally soluble, polarize and invert in the usual manner (p. 483). Where 
considerable starch or insoluble matter is present, use the double-dilution 
method of Wiley and Ewell (p. 503), thus making due allowance for 
the volume of the precipitate. 

Cane sugar, invert sugar, and dextrin, are determined as directed 
for honey. 



SUGAR AND SACCHARINE PRODUCTS. 521 

Commercial glucose is roughly determined by polarizing the sample 
at 87° C, as in the case of honey (p. 514). 

Confectionery is made in such a wide variety of forms, and these differ 
in consistency to such an extent that commercial glucose of all available 
degrees of density can be utilized to advantage in one product or another. 
In this respect confectionery is unlike honey and molasses, wherein a 
fairly uniform grade of commercial glucose is necessarily used for 
mixing, this grade being naturally selected with reference to its similarity 
in density to the molasses. On this account the glucose factor used 
for honey and molasses (175) may in some varieties of confectionery be 
too high. 

Determination of Alcohol in Syrups Used in Confectionery. — (Brandy- 
drops.) — Open each drop by cutting off a section with a sharp knife, and 
collect in a beaker the syrup of from 15 to 25 of the drops, which 
will usually yield from 30 to 50 grams of syrup. Strain the syrup into 
a tared beaker through a perforated porcelain filter-plate in a funnel 
to separate from particles of the inclosing shell, and ascertain the weight 
of the syrup. Wash into a distilling-flask, dilute with half its volume 
of water, and distil off into a tared receiving-flask a volume equal to the 
original volume of syrup taken. Ascertain the weight of the distillate 
and its specific gravity by means of a pycnometer. Multiply the per- 
centage by weight of alcohol corresponding to the specific gravity, as 
found in the tables on page 531 et seq., by the weight of the distillate, and 
divide this by the weight of syrup taken. The result is the per cent by 
weight of alcohol in the syrup. 

Detection of Colors. — It is some:imes necessary to macerate a con- 
siderable mass of the material to remo^•e the color, which is, however, 
in the majority of cases readily soluble. The insoluble colors are nearly 
all mineral pigments to be looked for in the ash, as in the case of chromate 
of lead (p. 519). Frequently the coloring matter is confined to a thin 
outer layer, which is readily washed off. 

The solution of the dyestuff is examined as directed under colors. 

Detection of Arsenic. — Arsenic may be present through impure 
coloring-matter. If the color is confined to an exterior coating, this 
should be washed off and examined. If distributed through the mass, 
a solution of the whole should be taken. Examine for arsenic by the 
Gutzeit or Marsh method, as directed under glucose (p. 511). 



522 FOOD INSPECTION /IND ANALYSIS. 



REFERENCES ON SUGARS. 

Babington, F. W. Sugars, Syrups, and Molasses. Can. Inl. Rev. Dept., Bui. 25. 

Maple Syrup. Can. Inl. Rev. Dept., Bui. 45. 

Bartley, E. H., and Mayer, J. L. Identification of Carbohydrates. Merck's Report, 

12, 1903, p. 100. 
Brown, H. T., Morris, G. H., and Millar, J. H. Experimental Methods em loyed 

in the Examination of . the Products of Starch Hydrolysis by Diastase. Jour. 

Chem. Soc. Trans., 71 (1897), p. 72. 
Frankel and Hutter. Starch, Glucose and Dextrin. Phila., 1881. 
Fresenius u. Mayrhofer, J. Der Starkesirup bei Zubereitung von Nahrungs- und 

Genussmitteln. Zeits. f. Unters. d. Nahr. u. Genussm., 1899, 21, 35 u. 279. 
Fruhling, R. Anleitung zur Untersuchung der fiir die Zuckerindustrie. 6th ed, 

Braunsweig, 1903. 
Landolt, H. Handbook of the Polariscope and its Practical Applications, 1882. 

Trans, by Long, J. H. Optical Rotation of Organic Substances. Easton, 1902. 

Leach, A. E. The Determination of Commercial Glucose in Molasses, Syrups and 

Honey. Jour. Am. Chem. Soc, 25, 1903, p. 982. 

Saccharine Products. U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 43. 

Lock and Newlands. A Handbook for Planters and Refiners. London, 18S8. 
Macfarlane, T. Honey. Can. Inl. Rev. Dept., Bui. 45. 

Robin, L. Sucres. Analyse des Matieres Alimentaires (Girard et Dupre), p. 525 

Paris, 1894. 
Roth, H. L. A Guide to the Literature of Sugar. London, i8go. 
Sachsse, R. Die Chemie der Kohlenhydrate. Leipzig, 1877. 
Shutt, F. F., and Charron, A. T. Determination of Moisture in Honey. Trans. 

Royal Soc. Canada, 2d Series, 1902-3, 7, Section 3. 
Sidersky, D. Traite d'Analyse des Matiferes Sucrees. Paris, 1890. 
Spencer, G. L. Handbook for Sugar Manufacturers and their Chemists. New 

York, 1897. 
Steydn, E. Die Untersuchung des Zuckers und Zuckerhaltiger Stoflfe. Leipzig, 1893. 
TOLLENS, B. Handbuch der Kohlenhydrate. Breslau, 1888. 
Tucker, J. H. Manual of Sugar Chemistry. New York, 1890. 
Weichmann, F. S. Sugar Analysis. New York, 1890. 
Wein, E. Tabellen zur quantitativen Bestimmung der Zuckerarten. 

Trans, by Frew, W Tables for the Quantitative Estimation of the Sugars. 

London, 1896. 
Wiley, H. W. Sugar, Molasses and Syrup, Confections, Honey and Beeswax. U. S. 

Dept. of Agric, Div. of Chem., Bui. 13, part 6. 



CHAPTER XIV. 

ALCOHOLIC BEVERAGES. 

Alcoholic Fermentation. — In a broad sense all alcoholic liquors are 
saccharine products, in that they are essentially the result of the fermen- 
tation of sugar. In the case of fruits, the sugar already exists as such 
in their juices, which, when expressed, almost immediately on exposure 
to the air begin to undergo spontaneously the process of alcoholic fermen- 
tation, in accordance with the reaction: 

(1) C,H,30e=2C3HeO+2C02. 
Dextrose or Alcohol Carbon 
grape stigar dioxide 

In the case of grains the process is more complex, involving a preliminary 
saccharous fermentation, whereby the starch is first transformed into 
sugar. 
Thus 

(2) 2CeH,oO,-f H3O = CeH,„0, + CJi,,0,. 

Starch Dextrin Dextrose 

(3) CeH,„0,+ H30 = CeH,,0,. 

Dextrin Dextrose 

The process of alcoholic or vinous fermentation is largely dependent 
upon the presence of various species of yeasts, which either exist from 
the first in the expressed juices themselves, as in the case of wines, being 
derived from the skins of the grapes and from the air, or are introduced 
with some degree of selection, as in the case of beer. 

In the juices of most fruits the sugar exists in the form of sucrose, 
mixed with variable amounts of invert sugar resulting from the inver- 
sion of the sucrose due to the action of ferments, such as invertase, a 
soluble ferment of yeast. The invert sugar nearly always predominates, 
and in some juices, as for instance the grape, nearly all the sugar has been 
inverted. 

523 



524 FOOD INSPECTION /IND AN /I LYSIS. 

The above reaction, No. i, illustrating the splitting up of grape sugar 
into alcohol and carbon dioxide, does not represent the practical yield 
of alcohol under ordinary conditions that occur in vinous fermentation, 
for, as a matter of fact, instead of 51.11 parts of alcohol and 48.89 parts 
carbon dioxide, which would theoretically result as above from the fer- 
mentation of 100 parts of dextrose, only about 95% of the theoretical 
yield can be obtained, so that in practice it is possible to form but about 
48.5% alcohol and 46.5% carbon dioxide. The balance, amounting 
to some 5%, consists chiefly of glycerin, succinic acid, and traces of 
various compounds, including some of the higher-boiling alcohols (propyl, 
butyl, and amyl) and their ethers, which form the fusel oil of the dis- 
tilled liquors. 

Vinous fermentation takes place most readily in slightly acid liquids, 
at a temperature ranging from 25° to 30° C. 

It is convenient to divide alcoholic beverages into two main groups, 
first the fermented and second the distilled liquors. The fermented 
liquors naturally subdivide themselves into (a) the products of the direct 
spontaneous fermentation of saccharine fruit juices, such, for example, 
as those of the apple and the grape, to form cider and wine respectively,- 
and {h) the malted and brewed liquors, such as beer and ale, produced 
by the conversion of the starch of grain into sugar, and the final alcoholic 
fermentation of the latter. 

The distilled liquors include such products as whiskey, brandy, rum, 
and gin, wherein alcoholic infusions prepared by previous fermentation 
in various ways are further subjected to distillation. 

Alcoholic Liquors and State (or Municipal) Control. — The mere 
adulteration of liquors docs not constitute the only feature which brings 
them within the scope of the public analyst's work and renders them 
especially amenable to stringent laws. Indeed, it is often a far more 
important question for the analyst to decide by his results whether or 
not the samples submitted to him, by police seizure or otherwise, are 
sold in violation of the regulations in force in his particular locality govern- 
ing the liquor traffic. 

A common regulation in no-license localities fixes the maximum per 
cent of alcohol which shall decide whether or not a liquor is legally a 
temperance drink, and can be sold as such with impunity. From its low 
content in alcohol, an analyst's findings regarding a certain sample may 
exonerate the dealer suspected of violating this law, while yet by the 
very reason of its being low in alcohol the same sample would be placed 



ALCOHOLIC BEyER/tGES. 525 

in the adulterated list as regards non-conformance to a standard of purity. 
While the raising of revenue is one purpose for the existence of these 
laws bearing on liquor license, an equally important object sought to be 
gained is doubtless the repression of intemperance. 

Toxic Effects. — A popular impression seems to exist that the toxic 
effects of an adulterated liquor are far worse from a temperance stand- 
point than those of a sample of good standard quality, and it is a common 
experience of the public analyst to have submitted to him by well-mean- 
ing temperance advocates samples which are alleged to have caused 
the worst forms of intoxication, and are thus suspected of being impure. 
As a matter of fact the chief adulterants of liquors are water, sugar, and, 
in the case of beer, various bitter principles and vegetable extractives, 
none of which are on record as being in themselves actively toxic* 

Alcohol is the one ingredient of liquor which, more than any other, 
produces a marked physiological effect. Many liquors, especially those 
of the distilled variety classed as adulterated, are so considered by reason 
of their low alcoholic content through watering or otherwise, hence this 
commonest form of adulteration, far from being detrimental in itself, is 
actually helpful to the temperance cause. 

Details of Liquor Inspection. — The same precautions should be 
carefully observed by officers making seizures of liquors for analysis, 
as by food inspectors, regarding safe delivery of the samples to the 
analyst. The following instructions are circulated by the State Board 
of Health of Massachusetts, which has in charge the inspection of liquors, 
concerning the taking of samples in that state and the transmission to 
the analyst: 

DIRECTIONS FOR TAKING SAMPLES FOR ANALYSES. 

The officer making a seizure, or taking samples of beer, should note 
at the time of such seizure the general appearance of the liquor, — as to 
whether it is clear or cloudy, whether it is still or has a strong head. 

If the liquor is in bottles, take at least one pint bottle; if in barrels, 
draw a pint bottle from each. Request the owner to seal each sample 
taken. If the bottles have cork stoppers, cut the stoppers off level with 
the top of the bottle and cover with wax; if with patent stoppers, a little 
wax placed upon the wire at the point where it lays against the neck of 
the bottle is sufficient. If the owner refuses to seal it, then the officer 

* The writer refers to substances Intentionally added, and not to accidental impurities, 
such as arsenic, etc., that are occasionally found. 



5^6 FOOD INSPECTION AND ANALYSIS. 

should seal it in his presence, calling his attention to the fact. Before 
leaving the premises, place upon the bottle a label or tag, with the date, 
the name of the owner, and the name of the officer upon it, and also the 
name of the town or city. Then place in a box, with the certificate 
required by law, and forward without delay to the analyst. 

FORM OF LABEL. 



Town 

Date of seizure 19 

Owner 

Kind of liquor 

Brewer 

Accompanying each sample is a certificate like the following, the 
first part of which is filled out and signed by. the officer, while the second 
part, containing the data of analysis, is filled out and signed by the analyst 
and returned by him to the officer. Such a certificate is nearly always 
accepted as evidence in court without the personal appearance of the 
analyst. . 

ss 19 . 

To the State Board of HeaUh: 

I send herewith a sample of 

taken from liquors seized by me 19 . 

Ascertain the percentage of alcohol it contains, by volume, at sixty 
degrees Fahrenheit, and return to me a certificate herewith upon the 
annexed form. 
Seized from 



Officer. 

COMMONWEALTH OF MASSACHUSETTS. 

No 

Office of the State Board of Health. 

Boston, 19 . 

This is to certify that the received by me 

with the above statement contains per cent of alcohol, 

by volume, at sixty degrees Fahrenheit. '°° 

Received 19 • 

Analysis made 19 . 



[seal.] Anal3'st State Board of Health. 



ALCOHOLIC BEyERAGES. 527 

A convenient method for recording analyses is by the employment 
of numbered library cards, which bear the same number as the certificates 
and are kept by the analyst. 

The following is a convenient form: 



No Analyzed 

County Wt. flask and ale 

City or town Wt. flask 

Officer Wt. ale 

Defendant Sp. gr. ale. (60°) 

Address Percent alcohol 

Kind of liquor Reported 

Seized 

Received 

How delivered 

Sealed 

Condition ' 

Kind of bottle 

Registered 

METHODS OF ANALYSIS COMMON TO ALL LIQUORS. 

Specific Gravity. — This should be taken at 15.6° or calculated to 
that temperature. The most convenient mode of procedure is to bring 
the temperature of the sample somewhat below that point by allowing 
the flask containing it to stand in cold water, and to have everything in 
readiness to make the determination when 15.6° temperature has been 
reached, either by the hydrometer spindle in a glass cylinder, by the 
Westphal balance, or by the pycnometer. The latter is by far the most 
accurate, especially if it is of the form which is fitted with a thermometer- 
stopper. 

Detection of Alcohol. — It is rarely necessary to make a qualitative 
test for alcohol in liquors, since it is almost invariably present even in 
many of the so-called temperance drinks, at least in small amovnt. 
Indeed in many localities a beverage is legally a temperance drink that 
contains not more than 1% alcohol by volume. 

The Iodoform Test. — Alcohol, when present in aqueous solution to 
the extent of 0.1% or more, may be detected by the iodoform test. The 
solution is warmed in a test-tube with a few drops of a strong solution 
of iodine in potassium iodide, after which enough sodium hydroxide 
solution is added to nearly decolorize. On standing for some time a 
yellow precipitate of iodoform will appear if alcohol be present, or at 
once if there is a considerable amount, and the characteristic odor of 
iodoform will be rendered apparent, even when the precipitate is so slight 
as to be almost imperceptible. This iodoform precipitate is crystalline, 
showing under the microscope as star-shaped groups or hexagonal tablets. 



$28 FOOD INSPECTION AND /tN /I LYSIS. 

It should not be forgotten that other substances than alcohol give the 
reaction, as lactic acid, acetone, and various aldehydes and ketones. 

Pure methyl or amyl alcohol or acetic acid do not thus react. 

Berthelot recommends benzoyl chloride as a reagent for detecting 
alcohol. By warming a mixture of a few drops of benzoyl chloride with 
the solution to be tested, and adding a little sodium hydroxide, ethyl 
benzoate is formed, recognizable by its distinctive odor. This reaction 
is delicate to o.i% alcohol. The presence of other alcohols than ethyl 
produces ethers of characteristic odor. 

Hardy s Test lor Alcohol consists in shaking the aqueous solution 
with some powdered guaiacum resin, filtering, and adding to the filtrate 
a little hydrocyanic acid and a drop of dilute copper sulphate solution. 
A blue coloration considerably deeper than that due to the copper salt 
is indicative of alcohol. 

Methyl Alcohol in spirits is tested for by Mulliken's reaction (p. 743). 

DETERMINATION OF ALCOHOL. — In the case of carbonated liquids it is 
necessary to first expel the free carbon dioxide, which is readily accom- 
plished by pouring the liquor back and forth from one beaker to another, 
from time to time removing the excess of froth from the top of the vessel 
by the aid of the hand. Or, the sample may be shaken \'igorously in a 
large separator)' funnel, and the still liquor drawn off from below the 
froth, repeating the operation several times if necessary. In either 
case the mechanical treatment should be continued till the liquor is com- 
paratively quiet and free from foam. 

If the liquor is perceptibly acid, the acidity should first be neutralized 
with sodium hydroxide or other alkali, to guard against the passing over 
of volatile acid. This is usually unnecessary with beer or distilled liquors, 
wherein the volatile acid is not generally present in sufficient quantity 
to perceptibly affect the result, but is a wise precaution to take with cider 
or wine. 

(i) By Distillation. — This is by far the most accurate method of 
determining alcohol, and should be carried out in all cases where any 
legal controversy is apt to be involved. A convenient quantity of the 
liquor, say 100 cc, from which the free carbon dioxide has been expelled 
is carefully measured out in a graduated flask with a narrow neck (such 
for example as a loo-cc. sugar-flask), neutralized, if acid, with sodium 
hydroxide, and washed into the distilling-flask with about one-fourth 
its volume of added water. The flask is then connected with the con- 
denser, and the contents distilled over a free flame, receiving the distillate 



ALCOHOLIC BEyER/tGES. 529 

for convenience and accuracy in the original flask in which it was measured. 
Nearly all alcoholic liquors, if comparatively free from carbon dioxide, 
will boil without undue frothing or foaming. New wine will occasionally 
give trouble in this regard, but foaming may usually be prevented in this 
case by the addition of tannic acid. In case of wine, cider, and beer 
all the alcohol will have passed over in the first 75 cc. of the distillate, 
or three-fourths the original measured volume, but with distilled liquors 
high in alcohol the process had better be continued till nearly 100 cc. or 
the original volume taken have passed over. If the condenser is of glass, 
one can observe when all the alcohol has been distilled over, for the reason 
that the mixed alcohol and water vapors in the upper portion of the con- 
denser present a striated or wavy appearance, readily apparent so long 
as the alcohol is passing over, while after all the alcohol has been distilled, 
the condenser-tube appears perfectly clear. The distillation is thus 
continued for some time after this striated appearance has ceased. The 
distillate in the receiving glass is finally made up to the mark or to the 
original volume of the liquor taken. Strictly speaking, the measure- 
ments before and after distillation should be made at 15.6° C, but, except- 
ing in case of distilled liquors, no appreciable error results from making 
both measurements at the same or room temperature. Another precau- 
tion formerly thought necessary was to have the delivery-tube from the 
condenser pass below the level of a little water in the receiving-flask 
from the start, but equally accurate results have been obtained by simply 
allowing the end of the condenser-tube to enter the narrow-necked flask. 

Fig. Ill shows a bank of six stills of the kind used in the author's 
laborator)' for alcohol determination in liquors. In each still the verti- 
cal glass worm-condenser, the round-bottomed distilling-flask, and the 
lamp, are supported by rings held by a single upright rod. The receiving- 
flask is readily connected with the condenser by means of a single bent 
tube provided with a rubber stopper. The cold-water pipe supplying 
the condensers is shown at the top, and the gas-supply pipe at the bottom. 

The distillate, made up to the original volume, is thoroughly shaken and 
its specific gravity taken at exactly 15.6° in a pycnometer, or by the Westphal 
balance. From the specific gravity the corresponding percentage of alcohol 
by volume is ascertained by reference to the accompanying tables. 

If alcohol by weight is desired, operate on 100 grams of the sample,, 
making up the distillate to the same weight. 

(2) From the Specific Gravity of the Sample. — In the case of dis- 
tilled liquors having very little residue, an approximation to the true 



53° FOOD INSPECTION AND ANALYSIS. 

percentage of alcohol may be obtained by using the alcohol table in con- 
nection with the specific gravity of the liquor itself. The accuracy of 
this method depends largely on the freedom from residue, being absolutely 
correct for mixtures of alcohol and water only. 

(3) By Evaporation. — Determine the specific gravity of the sample, 
evaporate a measured portion of the liquor (50 or 100 cc.) in a porcelain 




Fig. III.— Bank of Stills for Alcohol Determination. 

dish over the water-bath to one-fourth its bulk, make up to its original 
volume with distilled water, and determine the specific gravity of this 
second or dealcoholized portion. Add i to the original specific gravity, 
and from this subtract the second specific gravity. The difference is 
the specific gravity corresponding to the alcohol in the liquor, the per 
cent of which is found from the table. 

Example. — Suppose the specific gravity of the original sample to be 
0.9763 while that of the dealcoholized sample is 0.9872. Then 1.9763 — 
0.9872 = 0.9891. .". Per Cent by volume of alcohol = 8.io. 



/ILCOHOUC BEVERAGES. 



531 



SPECIFIC GRAVITY AND PERCENTAGE OF ALCOHOL. 
(According to Hehner.) 



Spec. 


Absolute Alcohol. 


Spec. 


Absolute Alcohol. 


Spec. 


Absolute Alcohol. 




















Grav. 

at 
15.6° C. 


Per 
Cent 


Per 
Cent 


Grams 


Grav. 

at 
15.5° C. 


Per 
Cent 


Pel 
Cent 


Grams 


Grav. 

at 
15.6° C. 


Per 
Cent 


Per 
Cent 


Grams 


by 


by Vol- 


per 


bv 


by Vol- 


per 


by 


by Vol- 


per 




Weight 


ume. 






Weight 


ume. 






Weight 


ume. 


100 cc 


1 .0000 


0.00 


0.00 


0.00 


















0.9999 


0.05 


0.07 


0.05 


0-9959 


2-33 


2-93 


2.32 


0.9919 


4.69 


5-86 


4-65 


8 


O.II 


0-13 


O.II 


8 


2-39 


3.00 


2.38 


8 


4-75 


5-94 


4.71 


7 


0.16 


0.20 


0.16 


7 


2.44 


3-°7 


2-43 


7 


4.81 


6.02 


4-77 


6 


0.21 


0.26 


0.21 


6 


2.50 


3-14 


2-49 


6 


4-87 


6.10 


4-83 


5 


0.26 


0-33 


0.26 


5 


2.56 


3.21 


2-55 


5 


4-94 


6.17 


4-9° 


4 


0.32 


0.40 


0.32 


4 


2.61 


3-28 


2.60 


4 


5.00 


6.24 


4-95 


3 


0-37 


0.46 


0-37 


3 


2.67 


3-35 


2.65 


3 


5.06 


6.32 


5.01 


2 


0.42 


0-53 


0.42 


2 


2.72 


3.42 


2.70 


2 


5-12 


6.40 


5-07 


I 


0.47 


0.60 


0.47 


I 


2.78 


3-49 


2.76 


I 


5-19 


6.48 


5-14 





0-53 


0.66 


°-53 





2.83 


3-55 


2.81 





5-25 


6-55 


5-20 


0.9989 


0.58 


0-73 


0.58 


0.9949 


2.89 


3.62 


2.87 


0.9909 


5-31 


6.63 


5.26 


8 


0.63 


0.79 


0.63 


8 


2-94 


3-69 


2.92 


8 


5-37 


6.71 


S-32 


7 


0.68 


0.86 


0.68 


7 


3.00 


3-76 


2.98 


7 


5-44 


6.78 


5-39 


6 


0.74 


0-93 


0.74 


6 


3.06 


3-83 


3-04 


6 


5-50 


6.86 
^-94 


5-45 


5 


0.79 


0-99 


0.79 


S 


3-12 


3-9° 


3-1° 


5 


5-56 


5-51 


4 


0.84 


1.06 


0.84 


4 


3.18 


3-98 


3-16 


4 


5.62 


7.01 


5-57 


3 


0.89 


1-13 


0.89 


3 


3-24 


4-05 


3-22 


3 


5-69 


7-09 


5.64 


2 


0-95 


1. 19 


0-95 


2 


3-29 


4.12 


3-27 


2 


5-75 


7-17 


5-70 


I 


1. 00 


1.26 


1 .00 


I 


3-35 


4.20 


3-33 


I 


5.81 


7-25 


S-76 





1.06 


1-34 


1.06 





3-41 


4.27 


3-39 





5-87 


7-32 


5-81 


0.9979 


1. 12 


1.42 


1. 12 


0.9939 


3-47 


4-34 


3-45 


0.9899 


5-94 


7-4° 


5-88 


8 


1. 19 


1.49 


1. 19 


8 


3-53 


4-42 


3-51 


8 


6.00 


7.48 


5-94 


7 


1-25 


1-57 


1-25 


7 


3-59 


4-49 


3-57 


7 


6.07 


7-57 


6.01 


6 


1-31 


1-65 


1-31 


6 


3-65 


4-56 


3-63 


6 


6.14 


7.66 


6.07 


S 


1-37 


1-73 


1-37 


5 


3-71 


4-63 


3-69 


S 


6.21 


7-74 


6.14 


4 


1-44 


1. 81 


1-44 


4 


3-76 


4.71 


3-74 


4 


6.28 


7-83 


6.21 


3 


1-50 


1.88 


1-5° 


3 


3.82 


4-78 


3-8° 


3 


6.36 


7-92 


6.29 


2 


1.56 


1.96 


1.56 


2 


3.88 


4-85 


3-85 


2 


6-43 


8.01 


6.36 


I 


1.62 


2.04 


1. 61 


I 


3-94 


4-93 


3-91 


I 


6. so 


8.10 


6-43 





i-6g 


2. 12 


1.68 





4.00 


5.00 


3-97 





6-57 


8.18 


6-50 


0.9969 


I-7S 


2.20 


1-74 


0.9929 


4.06 


5-08 


4-03 


0.9889 


6.64 


8.27 


6-57 


8 


1. 81 


2.27 


1.80 


8 


4.12 


5-16 


4-°9 


8 


6.71 


8.36 


6.63 


7 


1.87 


^■iS 


1.86 


7 


4.19 


5-24 


4.16 


7 


6. 78 


8-45 


6.70 


6 


1.94 


2-43 


1-93 


6 


4-25 


5-32 


4.22 


6 


6.86 


8.54 


6.78 


5 


2.00 


2-51 


1-99 


5 


4-31 


5-39 


4.28 


5 


6-93 


8-63 


6-85 


4 


2.06 


2.58 


2.05 


4 


4-37 


5-47 


4-34 


4 


7.00 


8.72 


6.92 


3 


2. II 


2.62 


2.10 


3 


4-44 


5-55 


4.40 


3 


7.07 


8.80 


6-99 


2 


2.17 


2.72 


2. 16 


2. 


4-5° 


5-63 


4.46 


2 


7-13 


8.88 


7-°5 


I 


2.22 


2-79 


2.21 


I 


4-56 


5-71 


4-52 


I 


7 20 


8.96 


7.12 





2.28 


2.86 


2.27 





4.62 


5-78 


4-58 





7-27 


9.04 


7.19 



532 



FOOD INSPECTION AND ANALYSIS. 



SPECIFIC GRAVITY AND PERCENTAGE OF ALCOHOL— (Co«/i»«erf). 



Spec. 
Grav. 

at 
15.6° C. 



0.9879 
8 

7 
6 

5 
4 



0.9869 
8 

7 
6 

S 
4 
3 

2 

I 
O 



Absolute Alcohol. 



Per 

Cent 

by 

Weight 



7-33 
7.40 

7-47 
7-53 
7.60 
7.67 

7-73 
7.80 
7.87 
7-93 

8.00 
8.07 
8.14 
8.21 
8.29 
8.36 

8.43 
8.50 

8-57 
8.64 



Per 

Cent 
by Vol- 
ume. 



0.9859 8.71 

8; 8.79 

8.85 

8-93 
9.00 
9.07 
9.14 
9.21 
9.29 
9-36 



0.9849 

8 

7 
6 

5 
4 
3 
2 
I 
o 



0.9839 
8 



10.00 
10.03 



10.15 
10.23 
10.31 
10.38 
5 ro.46 

4,i°-54 

3 10.62 

10.69 

10.77 

10.85 



9-13 

9 

9.29 

9-37 
9-45 
9-54 
9.62 
9.70 
9.78 
9. 86 

9-95 
0.03 
0.12 
0.21 
0.30 
0.38 
0.47 
0.56 
0.65 
0-73 



0.91 
1. 00 
1.08 
1. 17 
1.26 
1-35 
1-44 
1-52 
i.6i 

1.70 

1-79 
1.87 
1.96 
2.05 

2-13 
2.22 

2-31 
2.40 
2.49 

2.58 
2.68 

2-77 
2.87 
2.96 
3-°5 
3-15 
3-24 
3-34 
3-43 



Grams 

per 
100 cc. 



7-7° 
7-77 
7-83 

7-89 
7.96 
8.04 
8.10 
8.17 
8.24 

8-31 
8.38 

8.45 
8.52 

8.58 
8.66 

8-73 
8.80 
8.87 

8-93 
9.00 
9.07 
9.14 
9.22 

0.29 

9-35 
9.42 

9-49 
9-56 
9.64 
9.71 

9-77 
9.84 
9.92 

9-99 
10.06 
10.13 
10.20 
10.28 
10.36 
10.44 
10.51 

i°-S9 
10.67 



Spec. 
Grav. 

at 
15.6° C. 



0.9829 
8 

7 
6 

5 
4 

3 
2 

I 



.9819 
8 

7 
6 

5 

4 

.3 

2 

I 



.9809 
8 

7 
6 

5 
4 
3 
2 
I 
o 

0.9799 
8 

7 
6 

5 
4 
3 



0.9789 
8 

7 
6 

5 
4 
3 



Absolute Alcohol. 



Per 

Cent 

by 

Weight 



0.9 

1. 00 

i.o3 

I-15 

1-23 

1-31 

1.38 

1.46 

1-54 
1.62 

1.69 

1-77 

1-85 

1.92 

2.00 

2. 

2-^5 

2.23 
2.31 

2.38 

2.46 

2.54 
2.62 
2.69 

2.77 
2-85 
2.92 
3.00 
3.08 
3-15 

3-23 
3-31 
3-38 
3-46 
3-54 
3.62 

3-69 
3-77 
3-85 
3-92 

4.00 

4.09 

4.18 

4.27 

36 

45 

55 

64 

73 
82 



Per 
Cent 
by Vol- 
ume. 



3-52 
3.62 

3-71 
3-81 
3-90 
3-99 
4.09 
4.18 
4.27 
4.37 

4.46 

4-56 
4.65 

4-74 
4.84 

4-93 
5.02 
5-12 

5-21 

5-3° 



.40 
.49 
-58 
.68 

_-77 
15.86 
15.96 
16. OS 
16. IS 

16.24 



Grams 

per 
100 cc. 



43 

5 

61 

70 

80 



7.26 

7-37 
7-48 
7-59 
7-7° 
7.81 

7-92 
8.03 
8.14 
8.25 



°-73 
0.81 
0.89 
0-95 
i-°3 
I- II 
1. 18 
1.26 

1-33 
1. 41 



1.56 
1.64 
1.70 
1.78 

i-8s 
1.92 
2.00 
2.08 
2.14 

2.22 
2.30 

2-37 
2.44 

2-51 
2-59 
2.66 

2-74 
2.81 



2.96 
3-03 
3-10 
3-18 
26 

i5 
40 
48 
56 
63 



3-71 
3-79 
3.88 

3-96 
4-04 
4-13 
4-23 
4-32 
4-39 
4-48 



Spec. 
Grav. 

at 
15.6° C, 



0.9779 
8 
7 

6 

5 
4 
3 
2 



.9769 
8 

7 
6 

5 
4 
3 



0-9759 
8 

7 
6 

5 
4 
3 
2 



-9749 
8 

7 
6 

5 
4 
3 



°-9739 
8 

7 
6 

5 
4 
3 
2 



Absolute Alcohol. 



Per 

Cent 

by 

Weight 



4.91 
5.00 
5.08 

5-17 
5-25 
5-33 
5-42 
5-5° 
5-58 
5-67 

5-75 

5-83 

5-9 

6.00 

6.08 

6.15 
6.23 
6.31 
6.38 
6.46 

6-54 
6.62 
6.69 

6-77 

6 " 

6.92 

7.00 

7.08 

7-17 

7-25 

7-33 
7.42 

7-5° 
7-58 
7.67 

7-75 
7-83 
7.92 
8.00 
8.08 

8.15 
8.23 

8-31 
8.38 
8.46 
8.54 
8.62 
8.69 

8-77 
S.85 



Per 

Cent 

by Vol 



18.36 

18.48 

18.58 

18.68 

18.78 

18. 

18. 

19.08 

19. 1 

19.28 

19-39 
19.49 

•9-59 
19.68 
19.78 
19.87 
19.96 
20.06 
20.15 
20.24 

2°-33 
20.43 
20.52 
20.61 
20.71 
20.80 
20.89 
20.991 
21.09 



Grams 



21 


.19 


21 


■29 


21 


■39 


21 


-49 


21 


-S9 


21 


.69 


21 


•79 


21 


-89 


21 


-99 


22 


-09 


22 


18 


22 


27 


22 


36 


22 


46 


22 


55 


22 


64 


22 


73 


22 


82 


22 


92 


23 


01 


21 


10 



ALCOHOLIC BEl^ERAGES. 533 

SPECIFIC GRAVITY AND PERCENTAGE OF ALCOHOL— (Co««j««ed). 





Absolute Alcohol. 




Absolute Alcohol. 




Abso 


lute Alcohol. 


Spec. 








Spec. 








Spec. 






Grav. 

at 


Per 

Cent 


Per 
Cent 


Grams 


Gray. 

at 
iS.6°C. 


Per 
Cent 


Per 
Cent 


Grams 


Grav. 

at 
15.6° C. 


Per 
Cent 


Per 
Cent 


Grams 


15.6" C. 


by 


by Vol- 


per 


by 


by Vol- 


per 


by 


by Vol- 


per 




Weight 


ume. 


100 cc. 




Weight 


ume. 


100 cc. 




Weight 


ume. 


100 cc. 


0.9729 


18.92 


23-'9 


18.41 


0.9679 


22.92 


27-95 


22.18 


0.9629 


26.60 


32.27 


25.61 


8 


19.00 


23.18 


18.48 


8 


23.00 


28.04 


22.26 


8 


26.67 


32 


34 


25-67 


7 


19.08 


23-38 


18.56 


7 


23.08 


28.13 


22.33 


7 


26.73 


32 


42 


25-73 


6 


19.17 


23-48 


18.65 


6 


23-15 


28.22 


22.40 


6 


26.80 


32 


50 


25-79 


5 


19-25 


23-58 


18.73 


5 


23-23 


28.31 


22.47 


5 


26.87 


32 


58 


25-85 


4 


19-33 


23.68 


18.80 


4 


23-31 


28.41 


22.54 


4 


26.93 


32 


65 


25-91 


3 


19.42 


^Hl 


18.88 


3 


23-38 


28.50 


22.61 


3 


27.00 


32 


73 


25-98 


2 


19-5° 


23.88 


18.9s 


2 


23.46 


28.59 


22.69 


2 


27.07 


32 


81 


26.04 


I 


19-58 


23.98 


19-03 


I 


23.54 


28.68 


22.76 


1 


27.14 


32 


90 


26.10 





19.67 


24.08 


19.12 





23-62 


28.77 


22.83 





27.21 


32 


98 


26.17 


0.9719 


19-75 


24.18 


19.19 


0.9669 


23.69 


28.86 


22.90 


0.9619 


27-29 


ii 


06 


26.25 


8 


19-83 


24.28 


19.27 


8 


23-77 


28.95 


22.97 


8 


27-36 


ii 


15 


26.31 


7 


19.92 


24.38 


19-36 


7 


23-85 


29.04 


23-05 


7 


27-43 


a 


23 


26.37 


6 


20.00 


24.48 


19.44 


6 


23-92 


29-13 


23.11 


6 


27-50 


3i 


31 


26.43 


5 


20.08 


24-58 


19-51 


5 


24.00 


29.22 


23-19 


5 


27-57 


a 


39 


26.51 


4 


20.17 


24-68 


19-59 


4 


24.08 


29-31 


23-27 


4 


27.64 


a 


48 


26.57 


3 


20.25 


24-78 


19.66 


3 


24-15 


29.40 


23-33 


3 


27.71 


a 


56 


26.64 


2 


20.33 


24-88 


19-74 


2 


24.23 


29.49 


23.40 


2 


27.79 


a 


64 


26.71 


I 


20.42 


24.98 


19-83 


I 


24-31 


29-58 


23.48 


1 


27.86 


a 


73 


26.78 





20.50 


25-07 


19.90 





24.38 


29.67 


23-55 





27-93 


a 


81 


26.84 


o.97°9 


20.58 


25-17 


19.98 


0.9659 


24-46 


29-76 


23.62 


0.9609 


28.00 


33 


89 


26.90 


8 


20.67 


25.27 


20.07 


8 


24-54 


29.86 


23-70 


8 


28.06 


3i 


97 


26.96 


7 


20.75 


25-37 


20.14 


7 


24-62 


29-95 


23-77 


7 


28.12 


34 


04 


27.01 


6 


20.83 


25-47 


20.22 


6 


24.69 


30.04 


23.84 


6 


28.19 


34 


II 


27-07 


5 


20.92 


25-57 


20.30 


5 


24-77 


5°-^i 


23-91 


5 


28.25 


34 


18 


27-13 


4 


21. oc 


25-67 


20.33 


4 


24-85 


30.22 


23-99 


4 


28.31 


34 


25 


27.18 


3 


21.08 


25.76 


20.46 


3 


24.92 


30-31 


24-05 


3 


28.37 


34 


5i 


27.24 


2 


21.15 


25.86 


20.52 


2 


25.00 


30.40 


24-12 


2 


28.44 


34 


40 


27-31 


I 


21.23 


25-95 


20.59 


I 


25-07 


30.48 


24.19 


I 


28.50 


34 


47 


27-36 





21.31 


26.04 


20.67 





25.14 


30-57 


24.26 





28.56 


34 


54 


27.42 


0.9699 


21.38 


26.13 


20.73 


0.9649 


25.21 


30-65 


24-32 


0.9599 


28.62 


34 


61 


27.47 


8 


21.46 


26.22 


20.81 


8 


25.29 


30-73 


24-39 


8 


28.69 


34 


69 


27-53 


7 


21.54 


26.31 


20.89 


7 


25-36 


30-82 


24-46 


7 


28.75 


34 


76 


27-59 


6 


21.62 


26.40 


20.96 


6 


25-43 


30.90 


24-53 


6 


28.81 


34 


83 


27.64 


5 


21.69 


26.49 


21.03 


5 


25-50 


30.98 


24-59 


5 


28.87 


34 


90 


27.70 


4 


21.77 


26.58 


21. II 


4 


25-57 


31-07 


24.66 


4 


28.94 


34 


97 


27.76 


3 


21.85 


26.67 


21.18 


3 


25-64 


31-13 


24.72 


3 


29.00 


35 


05 


27.82 


2 


21.92 


26.77 


21.25 


2 


25-71 


31-23 


24-79 


2 


29-07 


35 


12 


27.89 


I 


22.00 


26.86 


21-33 


I 


25-79 


31-32 


24.86 


I 


29-13 


35 


20 


27-95 





22.08 


26.95 


21.40 





25.86 


31-40 


24-93 





29.20 


35 


28 


28. 00 


0.9689 


22.15 


27.04 


21.47 


0-9639 


25-93 


31-48 


24-99 


0.9589 


29.27 


35 


35 


28.07 


8 


22.23 


27-13 


21.54 


8 


26.00 


31-57 


25.06 


8 


29-33 


35 


43 


28.12 


7 


22.31 


27.22 


21.61 


7 


26.07 


31-65 


25.12 


7 


29.40 


35 


51 


28.18 


6 


22.38 


27-31 


21.68 


6 


26.13 


31-72 


25.18 


6 


29-47 


35 


58 


28.24 


5 


22.46 


27.40 


21.76 


5 


26.20 


31.80 


25-23 


5 


29-53 


35 


66 


28.30 


4 


22.54 


27.49 


21.83 


4 


26.27 


31 -88 


25-30 


4 


29.60 


35 


74 


28.36 


3 


22.62 


27-59 


21.90 


3 


26.33 


31-96 


25-36 


3 


29.67 


35 


81 


28.43 


2 


22. 6g 


27.68 


21.96 


2 


26.40 


32-03 


25-43 


2 


29-73 


35 


89 


28.48 


I 


22.77 


27.77 


22.01 


1 


26.47 


32.11 


25-49 


I 


29.8c 


35 


97 


28.54 





22.85 


27.86 


22.12 





26.53 


32.19 


25-55 





29.87 


36 


04 


28.61 



534 FOOD INSPECTION /IND ANALYSIS. 

SPECIFIC GRAVITY AND PERCENTAGE OF ALCOHOL— (Con;/««e</). 





Absolute Alcohol. 




Absolute Alcohol. 




Absolute Alcohol. 


Spec. 








Spec. 






Spec. 






















Grav. 

at 


Per 


Per 


Grams 


Grav. 
at 


Per 


Per 


Grams 


Grav. 
at 


Per 


Per 


Grams 


.5.6° C. 


Cent 
by 


Cent 
by Vol- 


per 
100 cc. 


15.6° C. 


Cent 
by 


Cent 
by Vol- 


per 

I GO cc. 


iS.6°C. 


Cent 
by 


Cent 
by Vol- 


per 
100 cc. 




Weight 


ume. 






Weight 


ume. 






Weight 


ume. 




0.9579 


29-93 


36.12 


28.67 


0-9529 


32-94 


39-54 


31-38 


0.9479 


35-55 


42-45 


33-70 


8 


30.00 


36.20 


28.73 


8 


33- 00 


39.61 


31-43 


8 


35 -60 


42-51 


33-75 


7 


30.06 


36.26 


28.78 


7 


33-06 


39-68 


31-48 


7 


35-65 


42-56 


33-79 


6 


30.11 


36-32 


28.82 


6 


33-12 


39-74 


31-53 


6 


35-70 


42.62 


33-83 


5 


30-17 


36-39 


28. 88 


5 


33-18 


39.81 


31-59 


5 


35-75 


42.67 


33-88 


4 


30.22 


36-45 


28.92 


4 


33-24 


39-87 


31-63 


4 


35-8° 


42-73 


33-92 


3 


30.28 


36-51 


28.98 


3 


33-29 


39-94 


31-69 


3 


35-85 


42-78 


33-97 


2 


30-33 


^M^ 


29-03 


2 


33-35 


40.01 


31-74 


2 


35-90 


42.84 


34-01 


1 


30-39 


36.64 


29.08 


I 


33-41 


40.07 


3'-o? 


I 


35-95 


42-89 


34-05 





30-44 


36-70 


29-13 





33-47 


40.14 


31.86 





36.00 


42-95 


34-09 


0.9569 


30-50 


36-76 


29.18 


o.95>9 


33-53 


40.20 


31-91 


0.9469 


36-06 


43-01 


34-14 


8 


30.56 


36.83 


29-23 


8 


33-59 


40.27 


31.96 


8 


36.11 


43-07 


34-09 


7 


30.61 


36.89 


29.27 


7 


33-65 


40-34 


32-01 


7 


36-17 


43-13 


34-24 


6 


30.67 


36-95 


29-33 


6 


33-71 


40.40 


32-07 


6 


36.22 


43-19 


34-28 


5 


30-72 


37-02 


29-38 


5 


33-76 


40-47 


32.12 


5 


36.28 


43.26 


34-34 


4 


30-78 


37.08 


29-43 


4 


^^■ll 


40-53 


32-17 


4 


36-33 


43-32 


34-38 


3 


30 -S3 


37-14 


29.48 


3 


33-88 


40.60 


32-22 


3 


36-39 


43-38 


34-44 


2 


30.89 


37-20 


29-53 


2 


33-94 


40.67 


32-27 


2 


36-44 


43-44 


34-48 


I 


30-94 


37-27 


29-58 


I 


34.00 


40.74 


32-32 


I 


36.50 


43-50 


34-54 





31.00 


37-34 


29.63 





34-05 


40-79 


32-37 





36-56 


43-56 


34-58 


0.95S9 


31.06 


37-41 


29.69 


0.9509 


34-10 


.40.84 


32.41 


0.9459 


36.61 


43-63 


34-63 


8 


31.12 


37-48 


29-74 


8 


34-14 


40.90 


32-45 


8 


36.67 


43-69 


34-69 


7 


31.19 


37-55 


29.81 


7 


34-19 


40-95 


32.49 


7 


36-72 


43-75 


34-73 


6 


31-25 


37-62 


29.86 


6 


34-24 


41.00 


32-54 


6 


36.78 


43-81 


34-79 


5 


i^-i' 


37-69 


29.91 


5 


34-29 


41-05 


32-59 


5 


36-83 


43-87 


34-83 


4 


31-37 


37-76 


29-97 


4 


34-33 


41. II 


32-63 


4 


36.89 


43-93 


34.88 


3 


31-44 


37-83 


30-03 


3 


34-38 


41.16 


32-67 


3 


36.94 


44.00 


34-92 


2 


31-50 


37-90 


30.09 


2 


34-43 


41.21 


32-71 


2 


37-00 


44-06 


34-96 


I 


31-56 


37-97 


30-14 


I 


34-48 


41.26 


32-75 


I 


37.06 


44.12 


35-02 





31-62 


38.04 


30.20 





34-52 


41-32 


32-79 





37-" 


44.18 


35-07 


0.9549 


31.69 


38.11 


30-26 


0.9499 


34-57 


41-37 


^'■li 


0.9449 


37-17 


44.24 


35-12 


8 


31-75 


38.18 


30-31 


8 


34-62 


41-42 


32.88 


8 


37-22 


44-30 


35-16 


7 


31.81 


38-25 


30-36 


7 


34-67 


41.48 


32-92 


7 


37-28 


44-36 


35-21 


6 


31-87 


38-33 


30.42 


6 


34-71 


41-53 


32.96 


6 


37-33 


44-43 


35-26 


5 


31-94 


38-40 


30.48 


5 


34-76 


41-58 


33- 00 


5 


37-39 


44-49 


35-31 


4 


32.00 


38-4; 


30-53 


4 


34-81 


41.63 


33-04 


4 


37-44 


44-55 


35-35 


3 


32.06 


38.53 


30-59 


3 


34-86 


41.69 


33-09 


3 


37-50 


44.61 


35-41 


2 


32.12 


^l-t 


30.64 


2 


34-90 


41-74 


33-13 


2 


37-56 


44-67 


35-46 


I 


32-19 


38.68 


30.71 


I 


34-95 


41.79 


33-17 


I 


37.61 


44-73 


35-51 





32-25 


38-75 


30-77 





35-00 


41.84 


33-21 





37-67 


44-79 


35-56 


0-9539 


32-31 


38.82 


30.81 


0.9489 


35-05 


41.90 


32.26 


0.9439 


37-73 


44.86 


35-60 


8 


32-37 


38.89 


30-87 


8 


35-10 


41-95 


33-30 


8 


37-78 


44.92 


35-65 


7 


32-44 


38-96 


30-93 


7 


35-15 


42.01 


33-34 


7 


37-83 


44.98 


35-70 


6 


32-50 


39-04 


30-99 


6 


35-20 


42.06 


33-39 


6 


37-89 


45-04 


35-75 


5 


32-56 


39-11 


31-05 


5 


35-25 


42.12 


33-43 


5 


37-49 


45-10 


35-80 


4 


32-62 


39.18 


31.10 


4 


35-30 


42.17 


33-48 


4 


38.00 


45-16 


35-85 


3 


32.69 


39-25 


31-15 


3 


35-35 


42.23 


33-53 


3 


38.06 


45-22 


35-90 


2 


32-75 


39-32 


31.20 


2 


35-40 


42.29 


33-57 


2 


38.11 


45-28 


35-95 


I 


32-Si 


39-40 


31.26 


I 


35-45 


42.34 


33-6i 


I 


38-17 


45-34 


36.00 





32-87 


39-47 


31-32 





35-50 


42.40 


33-65 





38-22 


45-41 


36-04 



ALCOHOLIC BEVERAGES. 53 S 

SPECIFIC GRAVITY AND PERCENTAGE OF KLCOnOl.— {Continued). 





Absolute Alcohol. 




Absolute Alcohol. 




Absolute Alcohol. 


Spec. 








Spec. 








Spec. 






Grav. 

at 
15.6° C. 


Per 
Cent 


Per 
Cent 


Grams 


Grav. 

at 
IS.6°C. 


Per 
Cent 


Per 
Cent 


Grams 


Grav. 

at 


Per 
Cent 


Per 
Cent 


Grams 


by 


by Vol- 


per 


by 


by Vol- 


per 


15.6° C. 


by 


by Vol- 


per 




Weight 


ume. 


100 cc. 




Weight 


ume. 


100 cc. 




Weight 


ume. 


100 cc. 


0.9429 


38.28 


45-47 


36.08 


0-9379 


40.85 


48.26 


38.31 


0.9329 


43-29 


5°-87 


40.38 


8 


38-33 


45-53 


36.13 


8 


40.90 


48.32 


38.35 


8 


43 


33 


50-92 


40.42 


7 


38-39 


45-59 


36.18 


7 


40.95 


48 ..37 


38.39 


7 


43 


39 


50.97 


40.46 


6 


38-44 


45-65 


36-23 


6 


41.00 


48.43 


38-44 


6 


43 


43 


51.02 


40.50 


5 


38.5° 


45-71 


36.28 


5 


41-05 


48.48 


38.48 


5 


43 


48 


51-07 


40.54 


4 


38.56 


45-77 


36.33 


4 


41.10 


48.54 


38-52 


4 


43 


52 


51.12 


40.58 


3 


38.61 


45-83 


36.38 


3 


41.15 


48.59 


38-58 


3 


43 


57 


51-17 


40.62 


2 


38.67 


45-89 


36.43 


2 


41.20 


48.64 


38.62 


2 


43 


62 


51.22 


40.66 


I 


38.72 


45-95 


36.48 


I 


41.25 


48.70 


^8.66 


I 


43 


67 


51-27 


40.70 





38.78 


46.02 


36-53 





41.30 


48.75 


38.7° 





43 


71 


51-32 


40.74 


0.9419 


38.83 


46.08 


36-57 


0.9369 


41.35 


48.80 


38-74 


0.9319 


43 


76 


51-38 


40.78 


8 


38-89 


46.14 


36.62 


8 


41.40 


48.86 


38-78 


8 


43 


81 


51-43 


40.81 


7 


38-94 


46.20 


36.67 


7 


41.45 


48.91 


38.82 


7 


43 


86 


51-48 


40.85 


6 


39.00 


46.26 


36.72 


6 


41-50 


48.97 


38-87 


6 


43 


90 


51-53 


40.89 


5 


39-05 


46.32 


36.76 


5 


41-55 


49.02 


38.91 


5 


43 


95 


51-58 


40.93 


4 


39.10 


46.37 


36.80 


4 


41.60 


49.07 


38.95 


4 


44 


00 


5 1 - 63 


40.97 


3 


39-15 


46.42 


36.85 


3 


41.65 


49.13 


38.99 


3 


44 


°5 


51.68 


41 .01 


2 


39.20 


46.48 


36.89 


2 


41.70 


49.18 


39. °4 


2 


44 


09 


51-72 


41-05 


I 


39-25 


46.53 


36.94 


I 


41.75 


49-23 


39.08 


I 


44 


14 


51-77 


41.09 





39-3° 


46.59 


36.98 





41.80 


49.29 


39-13 





44 


18 


51.82 


41 13 


9409 


39.35 


46.64 


37-°2 


°-9359 


41.85 


49-34 


39-17 


0.9309 


44 


23 


51.87 


41.17 


8 


39-40 


46.70 


37-°7 


8 


41.90 


49 4° 


39-21 


8 


44 


27 


51-91 


41.20 


7 


39-45 


46.75 


37-11 


7 


41-95 


49-45 


39-25 


7 


44 


32 


51.96 


41.24 


6 


39-5° 


46.80 


37-15 


6 


42.00 


49 50 


39-30 


6 


44 


36 


52.01 


41.28 


5 


39-55 


46.86 


37-19 


5 


42.05 


49-55 


39-34 


5 


44 


41 


52.06 


41-31 


4 


39.60 


46.91 


37-23 


4 


42.10 


49.61 


39-38 


4 


44 


46 


52.10 


41.35 


3 


39-65 


46.97 


37-27 


3 


42.14 


40.66 


39-42 


3 


44 


5° 


52.15 


41.49 


2 


39-7° 


47.02 


37-32 


2 


42.19 


49.71 


39-46 


2 


44 


55 


52.20 


41-43 


I 


39-75 


47.08 


37-36 


I 


42.24 


49.76 


39-50 


I 


44 


59 


52.25 


41-47 





39.80 


47-13 


37-41 





42.29 


49.81 


39-54 





44 


64 


52.29 


41-51 


0-9399 


39-85 


47-18 


37-45 


0.9349 


42-33 


49.86 


39-58 


0.9299 


44 


68 


52-34 


41-55 


8 


39-9° 


47-24 


37.49 


8 


42.38 


49.91 


39-62 


8 


44 


73 


52-39 


41-59 


7 


39-95 


47.29 


37-53 


7 


42.43 


49.96 


39-66 


7 


44 


77 


52-44 


41.63 


6 


40.00 


47-35 


37-58 


6 


42.48 


50.01 


39-70 


6 


44 


82 


52.48 


41.67 


5 


40.05 


47-40 


37-62 


5 


42.52 


50.06 


39-74 


5 


44 


86 


52-53 


41.70 


4 


40.10 


47-45 


37-67 


4 


42.57 


50. II 


39-78 


4 


44 


91 


52.58 


41-74 


3 


40.15 


47-51 


37-71 


3 


42.62 


50.16 


39-82 


3 


44 


96 


52.63 


41-77 


2 


40.20 


47-56 


37-75 


2 


42.67 


50.21 


39-86 


2 


45 


00 


52.68 


41.81 


1 


40.25 


47.62 


37-8° 


I 


42.71 


50.26 


39-90 


I 


45 


°5 


52.72 


41.85 





40.30 


47.67 


37-84 





42.76 


50.31 


39-94 





45 


09 


52-77 


41.89 


0.9389 


40.35 


47.72 


37-88 


0-9339 


42.81 


50-37 


39-98 


0.9289 


45 


14 


52.82 


41-93 


8 


40.40 


47-78 


37-92 


8 


42.86 


5°-42 


40.02 


8 


45 


i8 


52-87 


41.97 


7 


40.45 


47-83 


37-96 


7 


42.90 


5° -47 


40.06 


7 


45 


23 


52-91 


42.00 


e 


40.50 


47.89 


38.00 


6 


42.95 


50-52 


40. 10 


6 


45 


27 


52-96 


42.04 


5 


40-55 


47-94 


38.05 


5 


43-00 


50-57 


40.14 


5 


45 


32 


53 -oi 


42.08 


4 


40.60 


47-99 


38.09 


4 


43-05 


50.62 


40,18 


4 


45 


36 


53.06 


42.12 


3 


40.65 


48.05 


38.13 


3 


43-1° 


50.67 


40.22 


3 


45 


41 


53.10 


42. 16 


2 


40.70 


48.10 


38.18 


2 


43.13 


50.72 


40.26 


2 


45 


46 


53.15 


42.19 


I 


40-75 


48.16 


38.22 


I 


43-19 


50.77 


40.30 


I 


45 


5° 


53-20 


42.23 





40.80 


.;8.2i 


38.27 





43-24 


50.82 


40.34 





45-55 


53-24 


42.27 



536 FOOD INSPECTION AND ANALYSIS. 

SPECIFIC GRAVITY AND PERCENTAGE OF ALCOHOL— (Con/t»K/;<i). 





Absolute AlcohoL 


1 


Absolute Alcohol. 




Absolute Alcohol. 


Spec. 






Spec. 






Spec. 


















Grav. 

at 


Per 


Per 


Grav. 

at 


Per 


Per 


Grav. 
at 


Per 


Per 


15.6° C. 


Cent 


Cent 


15.6° C. 


Cent 


Cent 


15.6° C. 


Cent 


Cent 




by 


by Vol- 


by 


by Vol- 




by 


by Vol- 




Weight. 


ume. 




Weight. 


ume. 




Weight. 


ume. 


0.9279 


45-59 


53-29 


0.9229 


47.86 


55-65 


0.9179 


50-13 


57.97 


8 


45.64 


53-34 


8 


47-91 


55-69 


8 


50-17 


58.01 


7 


45.68 


53-39 


7 


47-96 


55-74 


7 


50.22 


58.06 


6 


45-73 


53-43 


6 


48.00 


55-79 


6 


50.26 


58.10 


5 


45-77 


53-48 


5 


48-05 


55-83 


S 


50-30 


58.14 


4 


45-82 


53-53 


4 


48.09 


55-88 


4 


50-35 


58.19 


3 


45.86 


53-58 


3 


48.14 


55-93 


3 


50-39 


58-23 


2 


45-91 


53-62 


2 


48.18 


55-97 


2 


50-43 


58.28 


I 


45-96 


53-67 


I 


48-23 


56.02 


I 


50.48 


58.32 





46.00 


53-72 





48.27 


56.07 





50-52 


5S-36 


0.9269 


46.05 


53-77 


0.9219 


48-32 


56.11 


0.9169 


50.57 


58.41 


8 


46.09 


53-81 


8 


48.36 


56.16 


8 


50.61 


58-45 


7 


46.14 


53-86 


7 


48.41 


56.21 


7 


50-65 


58-50 


6 


46.18 


53-91 


6 


48.46 


56-25 


6 


50-70 


58-54 


S 


46-23 


53-95 


5 


48-50 


56.30 


5 


50-74 


58-58 


4 


46.27 


54.00 


4 


48-55 


56.35 


4 


50-78 


58-63 


3 


46.32 


54-05 


3 


48.59 


56.40 


3 


50-83 


58.67 


2 


46.36 


54-10 


2 


48.64 


56.44 


2 


50-87 


58-72 


I 


46.41 


54-14 


I 


48.68 


56-49 


I 


50-91 


58.76 





46.46 


54-19 





48.73 


56-54 





50-96 


58-80 


0.9259 


46.50 


54-24 


0.9209 


48.77 


56.58 


0-9159 


51.00 


58.85 


8 


46-55 


54-29 


8 


48.82 


56.63 


8 


51-04 


58.89 


7 


46.59 


54-33 


7 


48.86 


56.68 


7 


51-08 


58-93 


6 


46.64 


54-38 


6 


48.91 


56.72 


6 


51-13 


58.97 


5 


46.68 


54-43 


5 


48.96 


56.77 


S 


51-17 


59-01 


4 


46.73 


54-47 


4 


49.00 


56.82 


4 


51-21 


59.05 


3 


46.77 


54-52 


3 


49-04 


56.86 


3 


51-25 


59.09 


2 


46.82 


54-57 


2 


49.08 


56.90 


2 


51-29 


59-14 


I 


46.86 


54.62 


I 


49.12 


56.94 


I 


51-33 


59-18 





46.91 


54-66 





49.16 


56-98 





51-38 


59.22 


0.9249 


46.96 


54-71 


0.9199 


49.20 


57-02 


! 0.9149 


51-42 


59.26 


8 


47-00 


54-76 


Proof 8 


49-24 


57.06 


8 


51.46 


59-30 


7 


47-05 


54.80 


7 


49-29 


57-10 


7 


51-50 


59-34 


6 


47.09 


54-85 


6 


49-34 


57.15 


6 


51-54 


59-39 


5 


47-14 


54-90 


5 


49-39 


57.20 


5 


51-58 


59-43 


4 


47-18 


54.95 


4 


49-44 


57.25 


4 


51-63 


59-47 


3 


47-23 


54-99 


3 


49-49 


57.30 


3 


51.67 


59-51 


2 


47-27 


55 -°4 


2 


49-54 


57.35 


2 


51-71 


59-55 


I 


47-32 


55-09 


I 


49.59 


57.40 


I 


51-75 


59 -.59 





47-36 


55-13 





49.64 


57.45 





51-79 


59-63 


0.9239 


47-41 


55-18 


0.9189 


49.68 


57-49 


0.9139 


51-83 


59.68 


8 


47-46 


55-23 


8 


49-73 


57-54 


8 


51.88 


59-72 


7 


47-50 


55-27 


7 


49.77 


57-59 


7 


51-92 


59-76 


6 


47-55 


55-32 


6 


49.82 


57-64 


6 


51-96 


59.80 


5 


47-59 


55-37 


S 


49.86 


57-69 


5 


52.00 


59-84 


4 


47-64 


55-41 


4 


49.91 


57-74 


4 


52-05 


59-89 


3 


47-68 


55-46 


3 


49.95 


57-79 


3 


52.09 


59-93 


2 


47-73 


55-51 


2 


50 -00 


57-84 


2 


52-14 


59-98 


I 


47-77 


55-55 


I 


50.04 


57-88 


I 


52-18 


60.02 





47.82 


55-60 





50.09 


58-92 





52.23 


60.07 



ALCOHOLIC BEVERAGES. 



537 



SPECIFIC GRAVITY AND PERCENTAGE OF ALCOHOL— (Co«ft"«Kcd). 





Absolute Alcohol. 




Absolute Alcohol. 




Absolute Alcohol. 


Spec. 






Spec. 






Spec. 






Grav. 


Per 


Per 


Grav. 


Per 


Per 


Grav. 


Per 


Per 


at 
15.6° C. 


Cent 


Cent 


at 
IS.6°C. 


Cent 


Cent 


at 
15.6° C. 


Cent 


Cent 


by 


by Vol- 


by 


by Vol- 


by 


by Vol- 




Weight. 


ume. 




Weight. 


ume. 




Weitht. 


ume. 


0.9129 


52.27 


60.12 


0.9079 


54-52 


62.36 


0.9029 


56.82 


64.63 


8 


52-32 


60.16 


8 


54-57 


62.41 


8 


56.86 


64-67 


7 


52-36 


60.21 


7 


54.62 


62.45 


7 


56-91 


64.71 


6 


52-41 


60.25 


6 


54-67 


62.50 


6 


56-95 


64-76 


S 


52-45 


60.30 


5 


54-71 


62.55 


5 


57-00 


64-80 


4 


52-50 


60.34 


4 


54-76 


62.60 


4 


57-°4 


64.85 


3 


52-55 


60.39 


3 


54-81 


62.65 


3 


57-08 


64.89 


2 


52-59 


60.44 


2 


54.86 


62.69 


2 


57-13 


64-93 


I 


52-64 


60.47 


I 


54-90 


62.74 


I 


57-17 


64.97 





52-68 


60.52 





54-95 


62.79 





57-21 


65.01 


0.9119 


52-73 


60.56 


0.9069 


55 -oo 


62.84 


o.goig 


57-25 


65-05 


8 


52-77 


60.61 


8 


55-05 


62.88 


8 


57-29 


65.09 


7 


52-82 


60.65 


7 


55-09 


62.93 


7 


57-33 


65-13 


6 


52.86 


60.70 


6 


55-14 


62.97 


6 


57-38 


65-17 


S 


52-91 


60.74 


5 


55-18 


63.02 


5 


57-42 


65.21 


4 


52-95 


60.79 


4 


55-23 


63.06 


4 


57-46 


65-25 


3 


53-00 


60.85 


3 


55-27 


63.11 


3 


57-50 


65.29 


2 


53-04 


60.89 


2 


55-32 


63-15 


2 


57-54 


65-33 


I 


53-09 


60-93 


I 


55-36 


63.20 


I 


57-58 


65-37 





53-13 


60.97 





55-41 


63-24 





57-63 


65.41 


0.9109 


53-17 


61.02 


0.9059 


55-45 


63-28 


0.9009 


57-67 


65-45 


8 


53-22 


61.06 


8 


55-50 


63-33 


8 


57-71 


65.49 


7 


53-26 


61.10 


7 


55-55 


63-37 


7 


57-75 


65-53 


6 


53-30 


61.15 


6 


55-59 


63-42 


6 


57-79 


65-57 


5 


53-35 


61.19 


5 


55-64 


63-46 


5 


57-83 


6s. 61 


4 


53-39 


61.23 


4 


55-68 


63-51 


4 


57-88 


65.65 


3 


53-43 


61.28 


3 


55-73 


63-55 


3 


57-92 


65-69 


2 


53-48 


61.32 


2 


55-77 


63.60 


2 


57-96 


65-73 


I 


53-52 


61.36 


I 


55-82 


63.64 


I 


58.00 


65-77 





53-57 


61 .40 





55-86 


63-69 





58.05 


65.81 


0.9099 


53-61 


61-45 


o.904q 


55-91 


63-73 


0.8999 


58.09 


65-85 


8 


53-65 


61.49 


8 


55-95 


63.78 


8 


58-14 


65-90 


7 


53-70 


61-53 


7 


56.00 


63-82 


7 


58-18 


65-94 


6 


53-74 


61.58 


6 


56.05 


63.87 


6 


58.23 


65.09 


5 


53-78 


61.62 


5 


56.09 


63.91 


5 


58.27 


66.03 


4 


53-83 


61.66 


4 


'56.14 


63.96 


4 


58.32 


66.07 


3 


53-87 


61.71 


3 


56.18 


64.00 


3 


58-36 


66.12 


2 


53-91 


61 -75 


2 


56-23 


64-05 


2 


58.41 


66.16 


I 


53-96 


61.79 


I 


56.27 


64.09 


I 


58-45 


66.21 





54.00 


61.84 





56.32 


64.14 





58-50 


66.25 


0.9089 


54-05 


61.88 


0.9039 


56.36 


64.18 


0.8989 


58-55 


66.29 


8 


54.10 


61-93 


8 


56.41 


64.22 


8 


58. S9 


66.34 


7 


54-14 


61.98 


7 


56.45 


64.27 


7 


58.64 


66.38 


6 


54-19 


62.03 


6 


56-30 


64.31 


6 


58.68 


66.43 


S 


54-24 


62.07 


5 


56-55 


64-36 


5 


58.73 


66.47 


4 


54-29 


62.12 


4 


56-59 


64.40 


4 


58.77 


66.51 


3 


54-33 


62.17 


3 


56-64 


64-45 


3 


58.82 


66.56 


2 


54-38 


62.22 


2 


56-68 


64.49 


2 


58.86 


66.60 


I 


54-43 


62.26 


I 


56-73 


64-54 


I 


58-91 


66.65 





54-48 


62-31 




1 


56-77 


64.-8 





58-95 


66.69 



538 FOOD INSPECTION AND AN/I LYSIS. 

SPECIFIC GRAVITY AND PERCENTAGE OF ALCOHOL— (CoH/mMcti). 



Spec. 


Absolute Alcohol. 


Spec. 


Absolute Alcohol. 


Spec. 


Absolute Alcohol. 














Grav. 

at 


Per 


Per 


Grav. 
at 


Per 


Per 


Grav. 
at 


Per 


Per 


15.6° C. 


Cent 


Cent 


15.6° C. 


Cent 


Cent 


15.6° C. 


Cent 


Cent 




by 


by Vol- 


by 


by Vol- 


by 


by Vol- 




Weight. 


ume. 




Weight. 


ume. 




Weight. 


ume. 


0.8979 


59.00 


66.74 


0.8929 


61.13 


68.76 


0.8879 


63-30 


70.81 


8 


59-04 


66.78 


8 


61.17 


68.80 


8 


63-35 


70.85 


7 


59-09 


66.82 


7 


61.21 


68.83 


7 


63-39 


70-89 


6 


59-13 


66.86 


6 


61.25 


68.87 


6 


63-43 


70.93 


S 


59-17 


66. go 


5 


61.29 


68.91 


5 


63.48 


70-97 


4 


59.22 


66.94 


4 


61.33 


68-95 


4 


63-52 


71.01 


3 


59.26 


66.99 


3 


61-38 


68.99 


3 


63-57 


71-05 


2 


59-30 


67-03 


2 


61.42 


69.03 


2 


63.61 


71.09 


I 


59-35 


67.07 


I 


61.46 


69.07 


I 


63-65 


71-13 





59-39 


67.11 





61.50 


69.11 





63.70 


71.17 


0.8969 


59-43 


67-15 


0.8919 


61.54 


69.15 


0.8869 


63-74 


71.22 


8 


59-48 


67. 19 


8 


61.58 


69.19 


8 


63-78 


71.26 


7 


59-52 


67.24 


7 


61.63 


69.22 


7 


63-83 


71-30 


6 


59-57 


67.28 


6 


61.67 


69.26 


6 


63-87 


71-34 


5 


59 -61 


67.32 


5 


61.71 


69.30 


5 


63-91 


71-38 


4 


59-65 


67.36 


4 


61-75 


69-34 


4 


63.96 


71.42 


3 


59.70 


67.40 


3 


61.79 


69.38 


3 


64.00 


71.46 


2 


59-74 


67-44 


2 


61.83 


69.42 


2 


64.04 


71-50 


I 


59-78 


67.49 


I 


61.88 


69-46 


I 


64.09 


71-54 





59-83 


67-53 





61.92 


69.50 





64.13 


71-58 


0.895Q 


59-87 


67-57 


0.8909 


61.96 


69-54 


0.8859 


64.17 


71.62 


8 


59-91 


67.61 


8 


62.00 


69.58 


8 


64.22 


71.66 


7 


59.96 


67.65 


7 


62.05 


69-62 


7 


64.26 


71.70 


6 


60.00 


67.69 


6 


62.09 


69.66 


6 


64-30 


71-74 


S 


60.04 


67-73 


S 


62.14 


69-71 


5 


64-35 


71.78 


4 


60.08 


67.77 


4 


62.18 


69-75 


4 


64-39 


71.82 


3 


60. 13 


67.81 


3 


62.23 


69.79 


3 


•64-43 


71.86 


2 


60. 17 


67-85 


2 


62.27 


69.84 


2 


64.48 


71-90 


I 


60.21 


67-89 


I 


62.32 


69.88 


I 


64.52 


71.94 





60.26 


67-93 





62-36 


69.92 





64-57 


71.98 


O.804q 


60.29 


67.97 


0.8899 


62.41 


69.96 


0.8849 


64.61 


72.02 


8 


60.33 


68.01 


, 8 


62-45 


70-01 


8 


64-65 


72.06 


7 


60.38 


68.05 


7 


62.50 


70.05 


7 


64.70 


72. 10 


6 


60.42 


68.09 


6 


62.55 


70.09 


6 


64-74 


72.14 


5 


60.46 


68.13 


5 


62.59 


70-14 


5 


64.78 


72.18 


4 


60.50 


68.17 


4 


62-64 


70-18 


4 


64-83 


72.22 


3 


60.54 


68.21 


3 


62.68 


70.22 


3 


64.87 


72.26 


2 


60.58 


68.25 


2 


62-73 


70-27 


2 


64.91 


72.30 


I 


60.63 


68 29 


I 


62.77 


70.31 


I 


64-96 


72-34 





60.67 


68.33 





62.82 


70.35 





65.00 


72.38 


0.8939 


60.71 


68.36 


0.8889 


62.86 


70.40 


0.8839 


65.04 


72.42 


8 


60.76 


68.40 


: 8 


62.91 


70-44 


8 


65.08 


72-46 


7 


60.79 


68.44 


7 


62.95 


70.48 


7 


65-13 


72.50 


6 


60.83 


68.48 


6 


63.00 


70.52 


6 


65-17 


72.54 


5 


60.88 


68.52 


5 


63.04 


70.57 


5 


65.21 


72-58 


4 


60.92 


68.56 


4 


63.09 


70.61 


4 


65 - 25 


72-61 


3 


60.96 


68.60 


1 3 


63-13 


70-65 


3 


65.29 


72-65 


2 


61.00 


68.64 


2 


63-17 


70.69 


2 


65.33 


72-69 


I 


61.04 


68.68 


I 


63.22 


70-73 


I 


65-38 


72-73 





61.08 


68.72 





63.26 


70.77 





65.42 


72-7) 



ALCOHOLIC BF.VER/tGES. 



539 



SPECIFIC GRAVITY AND PERCENTAGE OF ALCOHOL— (Con^nued). 





Absolute Alcohol. 




Absolute Alcohol. 


Spec. 


Absolute Alcohol. 


Spec. 






Spec. 










Grav. 


Per 


Per 


Grav. 


Per 


Per 


Grav. 


Per 


Per 


at 
15.6° C. 


Cent 


Cent 


at 
15.6° C. 


Cent 


Cent 


at 
15.6° C. 


Cent 


Cent 


by 


by Vol- 


bv 


by Vol- 


by 


by Vol- 




Weight. 


ume. 




Weight. 


ume. 




Weight. 


ume. 


0.8829 


65.46 


72.80 


0.8779 


67-58 


74-74 


0.8729 


69.67 


76.61 


8 


65-5° 


72.84 


8 


67.63 


74.78 


8 


69.71 


76.65 


7 


65-54 


72.88 


7 


67.67 


74-82 


7 


69-75 


76.68 


6 


65-58 


72.92 


6 


67.71 


74.86 


6 


69.79 


76.72 


5 


65-63 


72.96 


S 


67-75 


74.89 


5 


69.83 


76.76 


4 


65-67 


72.99 


4 


67-79 


74-93 


4 


69.88 


76.80 


3 


65-71 


73-03 


3 


67-83 


74-97 


3 


69.92 


76.83 


2 


65-75 


73-07 


2 


67.88 


7S-OI 


2 


69.96 


76.87 


I 


65-79 


73-11 


I 


67.92 


75-04 


I 


70.00 


76.91 





65-83 


73-15 





67.96 


75-08 





70.04 


76.94 


0.8819 


65.88 


73-19 


0.8769 


68.00 


75-12 


0.8719 


70.08 


76.98 


8 


65.92 


73.22 


8 


68.04 


75 -16 


8 


70.12 


77.01 


7 


65.96 


73.26 


7 


68.08 


75-19 


7 


70. 16 


77-05 


6 


66.00 


73-30 


6 


68.13 


75-23 


6 


70.20 


77.08 


S 


66.04 


73-34 


5 


68.17 


75-27 


5 


70.24 


77.12 


4 


66.09 


73-38 


4 


68.21 


75-30 


4 


70.28 


77-15 


3 


66.13 


73-42 


3 


68.25 


75-34 


3 


70.32 


77-19 


2 


66.17 


73-46 


2 


68.29 


75-38 


2 


70.36 


77.22 


I 


66.22 


73-50 


I 


68.33 


75-42 


I 


70.40 


77-25 





66.26 


73-54 





68.38 


75-45 





70-44 


77-29 


0.8809 


66.30 


73-57 


0.8759 


68.42 


75-49 


0.8709 


70.48 


77-32 


8 


66.35 


73-61 


8 


68.46 


75-53 


8 


70-52 


77-36 


7 


66.39 


73-65 


7 


68.50 


75-57 


7 


70.56 


77-39 


6 


66.43 


73-69 


6 


68.54 


75.60 


6 


70.60 


77-43 


S 


66.48 


73-73 


5 


68.58 


75-64 


5 


70-64 


77.46 


4 


66.52 


73-77 


4 


68.63 


75-68 


4 


70.68 


77-50 


3 


66.57 


73-81 


3 


68.67 


75-72 


3 


70.72 


77-53 


2 


66.61 


73-85 


2 


68.71 


75-75 


2 


70.76 


77-57 


I 


66.65 


73-89 


I 


68.75 


75-79 


I 


70.80 


77.60 





66.70 


73-93 





68.79 


75-83 





70.84 


77-64 


0.8799 


66.74 


73-97 


0.8749 


68.83 


75-87 


0.8699 


70.88 


77.67 


8 


66.78 


74-01 


8 


68.88 


75-90 


8 


70.92 


77.71 


7 


66.83 


74-05 


7 


68.92 


75-94 


7 


70.96 


77-74 


6 


66.87 


74.09 


6 


68.96 


75-98 


6 


71.00 


77.78 


S 


66.91 


74-13 


5 


69.00 


76.01 


5 


71.04 


77-82 


4 


66.96 


74-17 


4 


69.04 


76.05 


4 


71.08 


77-85 


3 


67.00 


74.22 


3 


69.08 


76.09 


3 


71-13 


77.89 


2 


67.04 


74-25 


2 


69.13 


76-13 


2 


71.17 


77-93 


I 


67.08 


74.29 


I 


69-17 


76.16 


I 


71.21 


77.96 





67-13 


74-33 





69.21 


76.20 





71-25 


78.00 


0.8789 


67.17 


74-37 


0.8739 


69.25 


76.24 


0.8689 


71.29 


78.04 


8 


67.21 


74.40 


8 


69.29 


76.27 


8 


71-33 


78.07 


7 


67-25 


74-44 


7 


69-33 


76-31 


7 


71-38 


78.11 


6 


67.29 


74.48 


6 


69-38 


76.35 


6 


71.42 


78.14 


S 


67-33 


74-52 


5 


69.42 


76-39 


5 


71.46 


78.18 


4 


67-38 


74-55 


4 


69.46 


76.42 


4 


71-50 


78.22 


3 


67.42 


74-59 


3 


69.50 


76.46 


3 


71-54 


78-25 


2 


67.46 


74-63 


2 


69-54 


76.50 


2 


71-58 


78.29 


I 


67.50 


74.67 


I 


69.58 


76-53 


I 


71-63 


78-33 





67-54 


74-70 





69.63 


76-57 





71.67 


78.36 



54° FOOD INSPECTION /IND ANALYSIS. 

SPECIFIC GRAVITY AND PERCENTAGE OF ALCOHOL— (Cow/mMeif). 





Absolute Alcohol. 




Absolute Alcohol. 




Absolute Alcohol. 


Spec. 






Spec. 






Spec. 


















Grav. 


Per 


Per 


Grav. 

at 


Per 


Per 


Grav. 

at 


Per 


Per 


at 
15.6° C. 


Cent 


Cent 


15.6° C. 


Cent 


Cent 


15.6° C. 


Cent 


Cent 


by 


by Vol- 


by 


by Vol- 


by 


by Vol- 




Weight. 


ume. 




Weight. 


ume. 




Weight. 


ume. 


0.8679 


71.71 


78-40 


0.8629 


73-83 


80.26 


0.8579 


76.08 


82.23 


8 


71-75 


78-44 


8 


73.88 


80.30 


8 


76-13 


82.26 


7 


71.79 


78-47 


7 


73-92 


80.33 


7 


76.17 


82.30 


6 


71-83 


78.51 


6 


73-96 


8°-37 


6 


76.21 


82.33 


S 


71.88 


78-55 


5 


74.00 


80.40 


5 


76.25 


82.37 


4 


71.92 


78.58 


4 


74-05 


80.44 


4 


76.29 


82.40 


3 


71.96 


78.62 


3 


74.09 


80.48 


3 


76-33 


82.44 


2 


72.00 


78.66 


2 


74-14 


80.52 


2 


76.38 


82.47 


I 


72.04 


78.70 


I 


74.18 


80.56 


I 


76.42 


82.51 





72.09 


78-73 





74-23 


80.60 





76.46 


82.54 


0.8669 


72-13 


78.77 


0.8619 


74-27 


80.64 


0.8569 


76-50 


82.58 


8 


72.17 


78.81 


8 


74-32 


80.68 


8 


76-54 


82.61 


7 


72.22 


78.85 


7 


74.36 


80.72 


7 


76.58 


82.65 


6 


72.26 


78.89 


6 


74.41 


80.76 


6 


76.63 


82.69 


s 


72.30 


78-93 


5 


74-45 


80.80 


5 


76.67 


82.72 


4 


72-35 


78.96 


4 


74-50 


80.84 


4 


76.71 


82.76 


3 


72-39 


79.00 


3 


74-55 


80.88 


3 


76.7s 


82.79 


2 


72-43 


79.04 


2 


74-59 


80.92 


2 


76.79 


82.83 


1 


72.48 


79.08 


I 


74-64 


80.96 


I 


76-83 


82.86 





72-52 


79.12 





74-68 


81.00 





76.88 


82.90 


0.8659 


72-57 


79.16 


0.8609 


74-73 


81.04 


0-8559 


76.92 


82.93 • 


8 


72.61 


79.19 


8 


74-77 


81.08 


8 


76.96 


82.97 


7 


72.65 


79-23 


7 


74-82 


81.12 


7 


77.00 


83.00 


6 


72.70 


79-27 


6 


74.86 


81.16 


6 


77.04 


83.04 


5 


72.74 


79-31 


5 


74.91 


81.20 


5 


77-08 


83-07 


4 


72.78 


79-35 


4 


74-95 


81.24 


4 


77-13 


83.11 


3 


72-83 


79-39 


3 


75.00 


81.28 


3 


77-17 


83.14 


2 


72.87 


79-42 


2 


75-05 


81.32 


2 


77.21 


83.18 


I 


72.91 


79.46 


I 


75-09 


81.36 


I 


77-25 


83.21 





72.96 


79-50 





75-14 


81.40 





77.29 


83-25 


0.8649 


73.00 


79-54 


0.8599 


75-18 


81.44 


0.8549 


77-33 


83.28 


8 


73-04 


79-57 


8 


75-23 


81.48 


8 


77-38 


83-32 


7 


73-08 


79.61 


7 


75-27 


81.52 


7 


77-42 


83-36 


6 


73-13 


79-65 


6 


75-33 


81.56 


6 


77-46 


83-39 


S 


73-17 


79-68 


5 


75-36 


81.60 


5 


77-50 


83.43 


4 


73-21 


79.72 


4 


75-41 


81.64 


4 


77-54 


83.46 


3 


73-25 


79-75 


3 


75-45 


81.68 


3 


77-58 


83-50 


2 


73-29 


79-79 


2 


75-50 


81.72 


2 


77-63 


83-53 


I 


73-33 


79-83 


I 


75-55 


81.76 


I 


77.67 


83-57 





73-38 


79.86 





75-59 


81.80 





77-71 


83.60 


0.8639 


73-42 


79-90 


0.8589 


75-64 


81.84 


0.8539 


77-75 


83-64 


8 


73-46 


79-94 


8 


75-68 


81.88 


8 


77-79 


83.67 


7 


73-50 


79-97 


7 


75-73 


81.92 


7 


77-83 


83-71 


6 


73-54 


80.01 


6 


75-77 


81.96 


6 


77.88 


83-74 


5 


73-58 


80.04 


5 


75-82 


82.00 


5 


77.92 


83.78 


4 


73-63 


80.08 


4 


75-86 


82.04 


4 


77.96 


83-81 


3 


73-67 


80.12 


3 


75-91 


82.08 


3 


78.00 


83-85 


2 


73-71 


80.15 


2 


75-95 


82.12 


2 


78.04 


83.88 


I 


73-75 


80.19 


I 


76.00 


82.16 


I 


78.08 


83-91 





73-79 


80.22 





76.04 


82.19 





78.12 


S3 -94 



/ILCOHOLIC BEVERAGES. 541 

SPECIFIC GRAVITY AND PERCENTAGE OF M^COnOl.— {Continued). 





Absolute Alcohol. 


Spec. 


Absolute Alcohol. 




Absolute 


Alcohol. 


Spec. 










Spec. 






Grav. 


Per 


Per 


Grav. 


Per 


Per 


Grav. 


Per 


Per 


at 
15-6° C. 


Cent 


Cent. 


at 

15.6° c. 


Cent 


Cent 


at 
15.6° C. 


Cent 


Cent 


by 


by Vol- 


by 


by Vol- 


by 


by Vol- 




Weight. 


ume. 




Weight. 


ume. 




Weight. 


ume. 


0.8529 


78.16 


83.98 


0.8479 


80.17 


85-63 


0.8429 


82.19 


87-27 


8 


78.20 


84.01 


8 


80.21 


85.66 


8 


82.23 


87-3° 


7 


78.24 


84.04 


7 


86.25 


85.70 


7 


82.27 


87-34 


6 


78.28 


84.08 


6 


80.29 


85-73 


6 


82.31 


87-37 


S 


78.32 


84.11 


5 


80.33 


85-77 


5 


82.35 


87.40 


4 


78.36 


84.14 


4 


80.38 


85.80 


4 


82-38 


87-43 


3 


78.40 


84.18 


3 


80.42 


8-5.84 


3 


82.42 


87.46 


2 


78.44 


84.21 


2 


80.46 


85-87 


2 


82.46 


87-49 


I 


78.48 


84.24 


I 


80.50 


85.90 


I 


82.50 


87.52 





78.52 


84.27 





80.54 


85-94 





82.54 


87-55 


0.8519 


78.56 


84.31 


0.8469 


80.58 


85.97 


0.8419 


82.58 


87.58 


8 


78.60 


84-34 


8 


80.63 


86.01 


8 


82.62 


87.61 


7 


78.64 


84.37 


7 


80.67 


86.04 


, 7 


82.65 


87.64 


6 


78.68 


84.41 


6 


80.71 


86.08 


1 6 


82.69 


87.67 


5 


78.72 


84.44 


5 


80.75 


86.11 


5 


82.73 


87.70 


4 


78.76 


84.47 


4 


80.79 


86.15 


4 


82.77 


87.73 


3 


78.80 


84-51 


3 


80.8^ 


86.18 


3 


82.81 


87.76 


2 


78.84 


84-54 


2 


80.88 


86.22 


2 


82.85 


87.79 


I 


78.88 


84-57 


I 


80.92 


86.25 


I 


82.88 


87-S2 





78.92 


84.60 





80.96 


86.28 





82.92 


87-85 


0.8509 


78.96 


84-64 


0.8459 


81.00 


86.32 


0.8409 


82.96 


87-88 


8- 


79.00 


84-67 


8 


81.04 


86.35 


8 


83.00 


87.91 


7 


79.04 


84.70 


7 


81.08 


86.38 


7 


83.04 


87.94 


6 


79.08 


84.74 


6 


81.12 


86.42 


6 


83-08 


87-97 


S 


79.12 


84-77 


5 


81.16 


86.45 


5 


83.12 


88.00 


4 


79.16 


84.80 


4 


81.20 


86.48 


4 


83-IS 


88.03 


3 


79.20 


84.83 


3 


81.24 


86-51 


3 


83-19 


88-06 


2 


79.24 


84.87 


2 


81.28 


86.54 


2 


83.23 


88.09 


I 


79.28 


84.90 


I 


81.32 


86.58 


I 


83-27 


88-13 





79-32 


84-93 





81.36 


86.61 





83-31 


88.16 


0.8499 


79-36 


84.97 


0.8449 


81.40 


86.64 


0.8399 


83-35 


88.19 


8 


79-40 


85.00 


8 


81.44 


86.67 


8 


83.38 


88.22 


7 


79-44 


85-03 


7 


81.48 


86.71 


7 


83.42 


88-25 


6 


79.48 


85.06 


6 


81.52 


86.74 


6 


83.46 


88.28 


S 


79-52 


85.10 


5 


81-56 


86.77 


5 


83-50 


88.31 


4 


79-56 


85-13 


4 


81.60 


86.80 


4 


S3 -54 


88.34 


3 


79.60 


85.16 


3 


81.64 


86.83 


3 


83-58 


88-37 


2 


79.64 


85.19 


2 


81.68 


86-87 


2 


83-62 


88-40 


I 


79.68 


85-23 


I 


81.72 


86.90 


I 


83-65 


88-43 





79.72 


85.26 





81.76 


86.93 





83.69 


88.46 


0.8489 


79.76 


85.29 


0-8439 


81.80 


86.96 


0.8389 


83-73 


88.49 


8 


79.80 


85-33 


8 


81.84 


86. 99 


8 


83-77 


88. 52 


7 


79.84 


85.36 


7 


81.88 


87.03 


7 


8s. 81 


88-55 


6 


79-88 


85.39 


6 


81.92 


87.06 


6 


83-85 


88.58 


.5 


79.92 


85.42 


5 


81.96 


87.09 


5 


83.88 


88.61 


4 


79.96 


85.46 


4 


82.00 


87.12 


4 


83-92 


88.64 


3 


80.00 


85-49 


3 


82.04 


87-15 


3 


83-96 


88.67 


2 


80.04 


85-53 


2 


82.08 


87.18 


2 


84-00 


88.70 


I 


80.08 


85-56 


I 


82.12 


87.21 


I 


84.04 


88.73 





80.13 


85-59 





82.15 


87.24 





84.08 


88.76 



542 FOOD INSPECTION AND /IN A LYSIS. 

SPECIFIC GRAVITY AND PERCENTAGE OF ALCOHOL— (Con/mwetf). 





Absolute Alcohol. | 




Absolute Alcohol. \ 




Absolute Alcohol. 








Spec. 
Grav. 

at 






Spec. 
Grav. 

at 






Spec. 
Grav. 

at 
15.6° C. 


Per 


Per 


Per 


Per 


Per 


Per 


Cent 


Cent 


15.6° C. 


Cent 


Cent 


15.6° C. 


Cent 


Cent. 


bv 


by Vol- 




by 


by Vol- 


by 


by Vol- 




Weight. 


ume. 




Weight. 


ume. 




Weight. 


ume. 


0.8379 


84.12 


88.79 


0.8329 


86.08 


90.32 


0.8279 


88.00 


91-78 


8 


84.16 


88.83 


8 


86.12 


90-35 


8 


88.04 


91-81 


7 


84.20 


88.86 


7 


86.15 


90.38 


7 


88.08 


91-84 


6 


84.24 


88.89 


6 


86.19 


90.40 


6 


88-12 


91.87 


5 


84.28 


88.92 


5 


86-23 


90-43 


5 


88.16 


91.90 


4 


84.32 


88.95 


4 


86.27 


90.46 


4 


88.20 


91-93 


3 


84.36 


88.98 


3 


86.31 


90-49 


3 


88.24 


91.96 


2 


84.40 


89.01 


2 


86.35 


90.52 


2 


88.28 


91.99 


I 


84.44 


89.05 


I 


86.38 


90-55 


I 


88.32 


92.02 





84-48 


89.08 





86.42 


90.58 





88.36 


92-05 


0.8369 


84.52 


89.11 


0.8319 


86.46 


90.61 


0.8269 


88.40 


92.08 


8 


84-56 


89.14 


8 


86.50 


90.64 


8 


88-44 


92. 12 


7 


84.60 


89.17 


7 


86.54 


90.67 


7 


88.48 


92-15 


6 


84.64 


89.20 


6 


86.58 


90.70 


6 


88.52 


92.18 


S 


84.68 


89.24 


5 


86.62 


90-73 


5 


88-56 


92.21 


4 


84.72 


89.27 


4 


86-65 


90.76 


4 


88.60 


92.24 


3 


84.76 


89-30 


3 


86.69 


90-79 


3 


88-64 


92.27 


2 


84.80 


89-33 


2 


86.73 


90.82 


2 


88.68 


92.30 


I 


84.84 


89.36 


I 


86.77 


90-85 


I 


88-72 


92.33 





84.88 


89-39 





86-81 


90-88 





88.76 


92.36 


0-8359 


84.92 


89.42 


0.8309 


86.85 


90.90 


0.8259 


88.80 


92-39 


8 


84.96 


89.46 


8 


86.88 


90-93 


8 


88-84 


92-42 


7 


85-00 


89-49 


7 


86.92 


90-96 


7 


88.88 


92-45 


6 


85.04 


89.52 


6 


86-96 


90.99 


6 


88-92 


92-48 


S 


85.08 


89-55 


5 


87.00 


91 -02 


5 


88.96 


92-51 


4 


85.12 


89-58 


4 


87-04 


91-05 


4 


89.00 


92-54 


3 


85-15 


89.61 


3 


87.08 


91.08 


3 


89-04 


92-57 


2 


85.19 


89.64 


2 


87.12 


91 -II 


2 


89-08 


92.60 


I 


85-23 


89.67 


I 


87-15 


91.14 


I 


89.12 


92.63 





85-27 


89-70 





87.19 


91.17 





89.16 


92.66 


0.8349 


85-31 


89-72 


0.8299 


87-23 


91.20 


0.8249 


89.19 


92.68 


8 


85-35 


89-75 


8 


87.27 


91-23 


8 


89-23 


92.71 


7 


85.38 


89.78 


7 


87-31 


91-25 


7 


89.27 


92.74 


6 


85-42 


89-81 


6 


87-35 


91.28 


6 


89.31 


92.77 


5 


85-46 


89-84 


5 


87.38 


91-31 


5 


89-35 


92.80 


4 


85-50 


89.87 


4 


87-42 


91-34 


4 


89.38 


92-83 


3 


85-54 


89.90 


3 


87-46 


91-37 


3 


89-42 


92.86 


2 


85-58 


89-93 


2 


87-50 


91.40 


2 


89-46 


92-89 


I 


85.62 


89-96 


I 


87-54 


91-43 


I 


89.50 


92.91 





85-65 


89.99 





87-58 


91-46 





89-54 


92.94 


0-8339 


85.69 


90 -02 


0-8289 


87.62 


91-49 


0.8239 


89.58 


92-97 


8 


85-73 


90-05 


8 


87-65 


91-52 


8 


89.62 


93.00 


7 


85-77 


90.08 


7 


87-69 


91-55 


7 


89-65 


93-03 


6 


85.81 


90.11 


6 


87-73 


91-57 


6 


89.69 


93.06 


S 


85-85 


90-14 


S 


87.77 


91 -60 


5 


89-73 


93-09 


4 


85.88 


90.17 


4 


87.81 


91.63 


4 


89.77 


93-11 


3 


85-92 


90.20 


3 


87-85 


91.66 


3 


89-81 


93-14 


2 


85.96 


90.23 


2 


87-88 


91-69 


2 


89-85 


93-17 


I 


86.00 


90.26 


I 


87.92 


91-72 


I 


89.88 


93.20 





86.04 


90.29 





87-96 


91-75 





89.92 


93-23 

1 



ALCOHOLIC BEVER/IGES. 543 

SPECIFIC GRAVITY AND PERCENTAGE OF KLCOKOX.— {Continued). 



Spec. 
Grav. 


Absolute Alcohol. | 


Spec. 
Grav. 


Absolute Alcohol. 


Spec. 
Grav. 


Absolute Alcohol. 














at 


Per 


Per 


at 


Per 


Per 


at 


Per 


Per 


15.6° c. 


Cent 


Cent 


15.6° C. 


Cent 


Cent 


15.6° C. 


Cent 


Cent 


by 


by Vol- 




by 


by Vol- 


by 


by Vol- 




Weight. 


' ume. 




Weight. 


ume. 




Weight. 


ume. 


0.8229 


89.96 


93.26 


0.8179 


91-7S 


94-53 


0.8129 


93-59 


95-84 


8 


90.00 


93-29 


8 


91-79 


94-56 


8 


93-63 


95-87 


7 


90.04 


93-31 


7 


91.82 


94-59 


7 


93-67 


95.90 


6 


90.07 


93-34 


6 


91.86 


94.61 


6 


93-70 


95.92 


5 


90.11 


93-36 


5 


91.89 


94.64 


5 


93-74 


95-95 


4 


90.14 


93-39 


4 


91-93 


94.66 


4 


93-78 


95-97 


3 


90.18 


93-41 


3 


91.96 


94-69 


3 


93-81 


96.00 


2 


90.21 


93-44 


2 


92.00 


94-71 


2 


93-85 


96-03 


I 


90.25 


93-47 


I 


92.04 


94-74 


I 


93-89 


96.05 





90.29 


93-49 





92.07 


94.76 





93-92 


96.08 


0.8219 


90.32 


93-52 


0.8169 


92.11 


94-79 


0.8119 


93-96 


96.11 


8 


90.36 


93-74 


8 


92-15 


94.82 


8 


94.00 


96.13 


7 


90-35 


93-57 


7 


92.18 


94.84 


7 


94-03 


96. 16 


6 


90-43 


93-59 


6 


92.22 


94-87 


6 


94.07 


96.18 


5 


90.46 


93.62 


5 


92.26 


94-90 


5 


94.10 


96.20 


4 


90.50 


93-64 


4 


92.30 


94.92 


4 


94.14 


96.22 


3 


90-54 


93-67 


3 


92.33 


94-95 


3 


94-17 


96.25 


2 


90-57 


93-70 


2 


92-37 


94.98 


2 


94.21 


96.27 


I 


90.61 


93-72 


I 


92.41 


95.00 


I 


94-24 


96.29 





90.64 


93-75 





92.44 


95 -°3 





94.28 


96.32 


0.8209 


90. 68 


93-77 


0.8159 


92.48 


95.06 


0.8109 


94-31 


96-34 


8 


90.71 


93.80 


8 


92.52 


95.08 


8 


94-34 


96.36 


7 


90-75 


■ 93-82 


7 


92.5s 


95-11 


7 


94-38 


96.39 


6 


90.79 


93-85 


6 


92-59 


95-13 


6 


94.41 


96.41 


S 


90.82 


93-87 


5 


92.63 


95-16 


5 


94-45 


96-43 


4 


90.86 


93-90 


4 


92.67 


95-19 


4 


94-48 


96.46 


3 


90.89 


93-93 


3 


92.70 


95-21 


3 


94-52 


96.48 


2 


90-93 


93-95 


2 


92.74 


95-24 


2 


94-55 


96. so 


I 


90.96 


93-98 


I 


92.78 


95-27 


I 


94-59 


96-53 





91 .00 


94.00 





92.81 


95-29 





94.62 


96-55 


0.8199 


91.04 


94-03 


0.8149 


92.85 


95-32 


. 8099 


94-65 


96-57 


8 


91.07 


94-05 


8 


92.89 


95-35 


8 


94-69 


96.60 


7 


91. II 


94.08 


7 


92.92 


95-37 


7 


94-73 


96.62 


6 


91.14 


94.10 


6 


92.96 


95-40 


6 


94-76 


96.64 


S 


91.18 


94-13 


5 


93.00 


95-42 


5 


94.80 


96-67 


4 


91.21 


94-15 


4 


93-04 


95-45 


4 


94-83 


96.69 


3 


91-25 


94.18 


3 


93-07 


95-48 


3 


94.86 


96.71 


2 


91.29 


94.21 


2 


93-11 


95-50 


2 


94.90 


96.74 


I 


91-32 


94-23 


I 


93-15 


95-53 


I 


94-93 


96-76 





91.36 


94.26 





93.18 


95-55 





94-97 


96.78 


0.8189 


91-39 


94.28 


0.8139 


93-22 


95-58 


0.8089 


95.00 


96.80 


8 


91-43 


94-31 


8 


93.26 


95.61 


8 


95-04 


96.83 


7 


91-46 


94-33 


7 


93-30 


95-63 


7 


95-07 


96.85 


6 


91.50 


94-36 


6 


93-33 


95-66 


6 


95-" 


96.88 


5 


91-54 


94-38 


5 


93-37 


95-69 


5 


95-14 


96.90 


■ 4 


91-57 


94.41 


4 


93-41 


95-71 


4 


95.18 


96-93 


3 


91.61 


94-43 


3 


93-44 


95-74 


3 


95-21 


96.95 


2 


91.64 


94.46 


2 


93-48 


95-76 


2 


95-25 


96.98 


I 


Q1.68 


04-48 


I 


93-52 


95-79 


I 


95-29 


97-00 





91.71 


94-51 





93-55 


95.82 





95-32 


97.02 



544 FOOD INSPECTION AND /IN A LYSIS. 

SPECIFIC GRA\aTY AND PERCENTAGE OF ALCOHOL— (Con/j««C(/). 





Absolute Alcohol. 




Absolute Alcohol. 


Spec. 


Absolute Alcohol. 


Spec. 






Spec. 










Grav 


Per 


Per 


Grav. 


Per 


Per 


Grav. 


Per 


Per 


at 
I5.6°C. 


Cent 


Cent 


at 
15.6° C. 


Cent 


Cent 


at 
15.6° c. 


Cent 


Cent 


by 


by Vol- 


by 


by Vol- 


by 


by Vol- 




Weight. 


ume. 




Weight. 


ume. 




Weight. 


ume. 


0.8079 


95-36 


97 -°5 


0.8029 


97.07 


98.18 


0.7979 


98.69 


9q.l8 


c 


95-39 


97.07 


8 


97.10 


98.20 


8 


98.72 


99-20 


7 


95-43 


97.10 


7 


97-13 


98.22 


7 


98-75 


99.22 


6 


95-46 


97.12 


6 


97.16 


98.24 


6 


98.78 


99-24 


5 


95-50 


97-15 


5 


97.20 


98.27 


5 


98.81 


99.26 


4 


95-54 


97.17 


4 


97-23 


98.29 


4 


98.84 


99-27 


3 


95-57 


97.20 


3 


97.26 


98.31 


3 


98.87 


99-29 


2 


95 -61 


97.22 


2 


97-30 


98-33 


2 


98.91 


99-31 


I 


95-64 


97.24 


I 


97-33 


98-35 


I 


98-94 


99-33 





95-68 


97.27 





97-37 


98-37 





98.97 


99-35 


0.8069 


95-71 


97.29 


0.8019 


97.40 


98-39 


0.7969 


99.00 


99-37 


8 


95-75 


97-32 


8 


97-43 


98.42 


8 


99-03 


99-39 


7 


95-79 


97-34 


7 


97.46 


98-44 


7 


99.06 


99.41 


6 


95.82 


97-37 


6 


97-50 


98.46 


6 


99.10 


99-43 


5 


95-86 


97-39 


5 


97-53 


98.48 


5 


99-13 


99-45 


4 


95-89 


97-41 


4 


97-57 


98.50 


4 


99.16 


99-47 


3 


95-93 


97-44 


3 


97.60 


98.52 


3 


99.19 


99-49 


2 


95-96 


97.46 


2 


97-63 


98-54 


2 


99-23 


99-51 


I 


96.00 


97-49 


I 


97.66 


98.56 


I 


99.26 


99-53 





96.03 


97-51 





97-70 


98-59 





99.29 


99-55 


0.8059 


96.07 


97-53 


0.8009 


97-73 


98.61 


0-79S9 


99-32 


99-57 


8 


96.10 


97-55 


8 


97.76 


98.63 


8 


99-36 


99-59 


7 


96.13 


97-57 


7 


97.80 


98-65 


7 


99-39 


99.61 


6 


96.16 


97.60 


6 


97-83 


98.67 


6 


99.42 


99-63 


5 


96.20 


97.62 


5 


97-87 


98.69 


5- 


99-45 


99-65 


4 


96.23 


97-64 


4 


97-90 


98.71 


4 


99.48 


99.67 


3 


96.26 


97.66 


3 


97-93 


98-74 


3 


99-52 


99-<5e 


2 


96.30 


97.68 


2 


97.96 


98.76 


2 


99-55 


99.71 


I 


96-33 


97.70 


I 


98.00 


98.78 


I 


99-58 


99-73 





96.37 


97-73 





98-03 


98.80 





99.61 


99-75 


0.8049 


96.40 


97-75 


0.7999 


98.06 


98.82 


0.7949 


99-65 


99-77 


8 


96-43 


97-77 


8 


98.09 


98-83 


8 


99.68 


99.80 


7 


96.46 


97-79 


7 


98.12 


98-85 


7 


99-71 


99.82 


6 


96.50 


97.81 


6 


98.16 


98.87 


6 


99-74 


99-84 


S 


96-53 


97-83 


S 


98.19 


98.89 


5 


99.78 


99.86 


4 


96-57 


97.86 


4 


98.22 


98.91 


4 


99.81 


99.88 


3 


96.60 


97.88 


3 


98.25 


98.93 


3 


99-84 


99.90 


2 


96.63 


97-90 


2 


98.28 


98.94 


2 


99-87 


99.92 


I 


96.66 


97.92 


I 


98.31 


98.96 


I 


99.90 


99-94 





96.70 


97-94 





98-34 


98.98 





99-94 


99.96 


0.8039 


96-73 


97-96 


0.7989 


98-37 


99.00 


0.7939 


99-97 


99-98 


8 


96.76 


97.98 


8 


98.41 


99.02 








7 


96.80 


98.01 


7 


98.44 


99.04 




Abs. 


Ale. 


6 


96.83 


98-03 


6 


98-47 


99-05 


0-7938 


100.00 


100.00 


5 


96.87 


98.05 


5 


98-50 


99-07 








4 


96.90 


98.07 


4 


98-53 


99.09 








3 


96.93 


98.09 


3 


98.56 


99.11 








2 


96.96 


98.11 


2 


98-59 


99-13 








I 


97.00 


98.14 


I 


98.62 


99-15 











97 -°3 


98.16 





98.66 


99.16 









ALCOHOLIC BEVERAGES, 



545 



(4) Determination of Alcohol by the Ebullioscope or Vaporimeter 

is based on the variation in boiling-point of mixtures of alcoliol and water, 
in accordance with the amount of alcohol present. There are various 
forms of this instrument, one of the simplest and most convenient being 
that of Salleron, Fig. 112, the apparatus being known in France as an 




8_ |-M-|-8 



16-g 
IS 



92- 



FiG. 112. — Salleron's Ebullioscope. FiG. 113. — Ebullioscope Scale. 

ebuUiometer. This consists of a jacketed metallic reservoir, heated by 
a lamp placed beneath, and fitted with a return-flow condenser at the 
top and with a delicate thermometer graduated in tenths of a degree. 

As the boiling-point of water varies with the atmospheric pressure, 
it is necessary to determine the actual boiling-point corresponding with 
the barometric conditions each time a series of determinations are made. 



54^ FOOD INSPECTION AND ANALYSIS. 

This is done by boiling a measured portion of distilled water in the reser- 
voir, and carefully noting the temperature when it becomes constant. 

The reservoir is then rinsed out with a little of the liquor to be tested, 
after which a measured amount of this liquor is boiled in the reservoir 
and the temperature again noted. A sliding scale (Fig. 113) accompanies 
the instrument, having three graduated parts as shown. The central 
movable portion is graduated in degrees and tenths of a degree centi- 
grade, the part at the left has the per cent of alcohol corresponding to 
the temperature in the case of simple mixtures of alcohol and water, 
while the part at the right is used for reading the per cent in the case of 
wine, cider, beer, etc., which have a considerable residue. The movable 
scale bearing the degrees of temperature is first set with the actual tem- 
perature of boiling water (as ascertained) opposite the o mark on the 
stationary.' scale. Suppose the temperature of boiling water has been 
found to be 100.1°. The scale is in this case set as shown in Fig. 113. 
Suppose also the temperature of boiling of the wine to be tested is 
found to be 89.3°. From the right-hand scale the corresponding per cent 
of alcohol is found to be 17.2. 

When the liquor to be tested contains more than 25% of alcohol, it 
is necessar)' to dilute with a measured amount of distilled water and 
calculate the per cent from the dilution. 

When once the boiling-point of water has been determined for a given 
barometric pressure, it is unnecessary to change the position of the slid- 
ing scale during a series of alcohol determinations unless that pressure 
changes. 

Expression of Results. — Some confusion is caused by the three ways 
of expressing results of the alcohol determination, whether as per cent by 
weight, per cent by volume, or grams per 100 cc. The particular mode 
adopted should depend upon the nature of the case and upon the prevail- 
ing custom. In laboratory analyses, unless othervdse qualified, the simple 
e.xpression of "per cent" usually implies per cent by weight, and for 
the reason that this conforms with other determinations, the adoption 
of the weight -percent age plan is perhaps most natural to the chemist on 
the grounds of uniformity. 

In enforcing the laws regulating the liquor traffic, the custom leans 
to volume percentage, and many of the laws are based on the "volume 
of alcohol at 60° F." (see p. 526). 

In recent years many European analysts have adopted the custom of 
expressing results of analyses of wines and other liquors in grams per 



/ILCOHOUC BEVERAGES. 547 

100 cc. and, in order to have a common basis of comparison between 
the composition of American and of European wines, this manner of 
expression has to some extent been adopted in the United States. 

Still another mode of expression, and a cumbersome one, is that 
of the English excise, wherein the alcoholic strength is referred for a 
standard to so-called "proof spirit," fixed by Parliament as a liquid of 
specific gravity 0.91984 at 15.5° C, which accordingly contains 49.24% 
by weight or 57.06% by volume of absolute alcohol. If a liquor is stronger 
in alcohol than this, it is said to be overproof, and if weaker, underproof. 
Its strength is further expressed in degrees over or under, water being 
regarded as 100° underproof. By liquor of 20° underproof, for instance, 
is meant that it consists of 80 parts by volume of proof-spirit and 20 parts 
by volume of water at 15.5° C, while by 20° overproof is meant that 
at that temperature 100 parts by volume of the liquor has to be diluted 
to 1 20 parts to yield proof spirit. 

To calculate the per cent by volume of proof spirit from the per cent 
of alcohol by volume, divide the latter by 0.5706 or multiply it by 1.7525. 

Direct Determination of Extract. — In liquors having a high sugar 
content, the extract or total solids cannot be determined accurately by 
evaporation at the temperature of boiling water, owing to the dehydra- 
tion of the reducing sugars at temperatures exceeding 75°. When extreme 
accuracy is required, such liquors should be dried in vacuo at 75°, or in 
a McGill oven (p. 481). 

Approximate results satisfactorj' in most cases are obtained by heat- 
ing for two and one-half hours 10 grams of the liquor in a tared platinum 
dish at the temperature of boiling water. If the results are to be expressed 
in grams per 100 cc, instead of weighing out 10 grams, 10 cc. of the liquor 
are measured by a pipette into a tared dish. With distilled liquors having 
low residues, accurate results are obtainable by direct evaporation at 
100°, using preferably 25 grams or 25 cc. according as the result is to be 
expressed in per cent by weight or grams per 100 cc. 

Extract in wine and beer is more readily calculated indirectly from 
their specific gravity as noted elsewhere. 

Determination of Ash. — The residue from the determination of the 
extract is incinerated to a white ash in the original dish at a low red heat, 
either over a Bunsen flame or in a muffle. The dish is finally cooled in 
a desiccator and weighed. 

Preservatives and Artificial Sweeteners in liquors are identified as 
described in Chapters XVII and XVIII. 



548 



FOOD INSPECTION AND ANALYSIS. 



FERMENTED LIQUORS. 

The fermented juices of many varieties of fruits and berries furnish 
beverages more or less popular in various localities, especially for home 
consumption, though, with the exception of the products of the apple and 
the grape, few of them are found on the market. The following table 
shows the average percentage of sugar and free acid in the expressed 
juice or must of fruits, according to Fresenius, arranged in the order 
of their sugar content: 



Per Cent Sugar. 



Peaches 

Apricots 

Plums 

Green gages . . . 
Raspberries. .. . 
Blackberries. . . 
Strawberries. . . 

Currants 

German prunes 
Gooseberries. .. 

Pears 

Apples 

Mulberries 

Sour cherries. . . 
Sweet cherries. . 
Grapes 



1-99 

2-13 

2.8o 
4.18 
4.84 

5-32 
6.89 

7-3° 
7-56 
8.00 

8.43 
9.14 

O-OO 

0.44 

5-3° 
6. IS 



Per Cent Free 
Acid as Malic. 



85 
29 

72 
67 
80 
42 
57 
43 
08 

63 

og 
82 
02 
52 
88 
80 



CIDER. 

Cider is the expressed juice of the apple. When fresh and before 
fermentation has set in, it is known as sweet cider, but it does not long 
remain in this condition, developing after a good fermentation from 3 to 
6 per cent of alcohol by volume. 

The predominating yeast under the influence of which the fermenta- 
tion of cider takes place is Saccharomyces apiculatns, found in consider- 
able quantity on the outside of the apples as well as in the soil in which 
the trees grow. 

Process of Manufacture. — The best cider is made from ripe fruit, 
taking care to avoid the green and the rotten apples, both of which impair 
the quality of the product. After gathering, the apples are best allowed to 
stand in piles until perfectly ripe, being kept under cover. If exposed 
to the weather, certain of the yeast organisms found on the skins of the 
apples that are useful in promoting subsequent fermentation would be 



ALCOHOLIC BEVER/tGES. 549 

washed off. As a rule the apples commonly used by farmers for cider- 
making are those that are unsalable or unfit for other purposes, being 
chiefly windfalls or bruised and imperfect fruit. The apples are usually 
first crushed in a mill to a coarse pulp, which is afterward subjected to 
pressure in a suitable press and the juice thus extracted. 

In this country but little attention is paid to the after processes, the 
juice being usually transferred directly to barrels, which are not always 
particularly clean, and allowed to ferment spontaneously in a convenient 
place, subject to changes in temperature. There is little wonder that 
cider so made will keep but a short time and quickly goes over into vinegar, 
unless sahcylic acid or other an'Jseptic is added. 

In France more care is taken to regulate the temperature of fermen- 
tation, to insure absolute cleanness of all receptacles, and to separate 
out contaminating impurities. A preliminary fermentation is usually 
given to the juice in open vats, during which the yeast spores are 
developed, while impurities separate out both by rising to the surface 
and by settling to the bottom, care being taken to avoid the develop- 
ment of acetic fermentation. At the proper time the juice is "racked 
off" or drawn from the clear portion between the top and bottom, trans- 
ferred to scrupulously clean barrels, and allowed to undergo a second 
fermentation at a lower temperature than before. 

Sometimes the "racking off" is repeated, and the juice is further 
clarified by "fining" or treating with isinglass, which carries down certain 
albuminous substances. 

Cider thus made is capable of keeping a ver}' long time. 

In England cider is sometimes "fined" by treatment with milk, one 
quart of the latter being added to eighteen gallons of cider. 

The apple pomace, left as a residue, is generally steeped in water 
and repressed. The juice from the second pressing is occasionally added 
to the first for cider manufacture, but more often is concentrated and 
made into apple jelly, or used as a fortifier for vinegar to make up 
deficiency in solids. 

Composition of Cider. — The following tables, due to Browne,* show 
the chemical composition of the freshly expressed juice of several 
American varieties of apple, as well as that of a few fermented samples 
of cider of known purity. 

* Penn. Dept. of Agric, Bui. 58. 



5SO 



FOOD INSPECTION AND ANALYSIS. 



APPLE JUICES. 






OJ U) 

ctn 



« 



n] bo 



iSS 



•OS 



E 0) « 
o ci^.:i 

S - ■ 0) 



Red astrachan . . . . 

Early harvest 

Yellow transparent 
Early strawberry'. . 

Sweet bough 

Baldwin, green. ... 

' ' ripe 

Ben Davis 

Bellflowcr 

Tulpahocken 

Unknown 



i-°53i7 
1.05522 
1.05020 
1.04949 
1.04979 
1.04882 
1.07362 
1.05389 
I .06270 
J. 05727 
I. 05901 



11.78 


6.87 


13-29 


7-49 


II. 71 


8.03 


II. 81 


5-47 


11.87 


7.61 


11.36 


6.96 


16.82 


7-97 


12.77 


7. II 


14.90 


9.06 


13-94 


9.68 


13-75 


10.52 



3-63 

3-97 
2.10 
4-21 
3.08 
1.63 
7-05 
3-85 
4-32 
3-11 
2-31 



10.50 10. 



11.46 

10.14 

9.68 

10.69 

8-59 
15.02 
10.96 

13-38 
12.79 
12.83 



1. 14 


°-37 


0.77 


0.90 


0.28 


0.65 


0.86 


0.27 


0.44 


0.78 


0.24 


I. II 


0. 10 






1.24 


°-3i 


1.22 


0.67 


0.26 


0.87 


0.46 


0.28 


1.07 


0.58 


0.28 


0.66 


0.26 


0.24 


0.49 


0.44 


0.26 


0.22 



23.72 
24.32 

19.24 
39-40 

36.16 

49.00 

39.20 

48.20 

44.18 



FERMENTED CIDER (MIXED APPLES). 





















Rotation, 




Specific 
Gravity. 


SoUds. 


Invert 
Sugar. 


Malic 
Acid. 


Acetic 
Acid. 


Alcohol. 


Pectin. 


Ash. 


400-nim. 

Tube. 
Ventzke 

Scale. 
Degrees 

to the 

Left. 


A... 


I .99805 


1-94 


0.19 


0.21 


0.24 


6.85 


0.03 


0.25 


2.30 


Ji... 
C... 


I. 00122 
1.00525 


2.71 
3.26 


0.19 
0.89 


0.24 
0.30 


0.42 
0.48 


5-13 
4.67 


0.03 
0.05 


0.32 
0.29 


2-49 
5.28 


D. . 

E... 


1. 0007 1 
I. 00512 


1-93 
2.71 


0-34 
. 0.24 


0.27 
0.29 


0.21 
1.96 


4-95 
4.26 


0.05 
0.06 


0.23 
0.36 


2.00 
1.76 



The following arc summaries of the results of a large number of 
analyses of European apple juices made by Truelle, the quantities being 
expressed in grams per liter: 



Specific gravity 

Invert sugar 

Sucrose 

Total fermentable sugars (as dextrose) . 

Tannin 

Pectin and albuminous substances 

Acidity (sulphuric acid) 



Mean. 



1.0760 

135-85 

25.01 

162.18 

2.90 

12 

2.14 



Minimum. 



1-0573 
108.^8 

5-58 
119.22 
0.26 
o 
0.69 



Maximum. 



1. 1 100 
181. 81 
71.7 

231-57 
8.07 

23 
7.41 



ALCOHOLIC BEVERAGES. 



551 



In the municipal laboratory of Paris, Sangle Ferribre has analyzed 
eleven samples of known-purity cider with the following results: 











Sugar per 
Liter. 










Aciditv as 
HjSO,. 




>■ 


C c 
U 3 






m 







u 


Alkalinity 
Ash. as 
K2CO3 per 
Liter. 




■2 

X 

E 


Mean 


I. 0159 


3-9 


52.67 


21.31 


21.62 


-4°. 


26 


,,.26 


2.^6 


5-27 


2-55 


Maximum 


I. 0410 


6.2 


114.00 


59-40 


60.80 


-11°. 


20 


4-32 


3.68 


6-59 


2.94 


Minimum. . . 


I. 001 2 


I.I 


22.62 


Trace 


Trace 







2.48 


2. 04 


4.20 


1-47 



Six samples of bottled "sweet" cider purchased in Massachusetts 
were analyzed in the Food and Drug Laboratory of the Board of Health 
with the following results: 





Per Cent 

Almhol by 

Weight. 


Per Cent 
Acid as 
iHaUc. 


Per Cent 
E.xtract. 




8.00 
3-55 
5-71 


0.72 
0.48 
0.58 


7.82 
2.42 
4.19 


Minimum 







Browne gives the following as the composition of the mixed ash of 
several varieties of apple: 



Ingredient. 



Per- 
cent- 
age. 



Ingredient. 



Per- 
cent- 
age. 



Potash (K,0) 

Soda (Na^b) 

Lime (CaO) 

Magnesia (MgO) 

O.xide of iron (FcoOj) 

O.xide of aluminum (AljOj) 

Chlorine (CI) 

Silica (SiOj) 

Sulphuric acid (SO3) 

Phosphoric acid (P2O5) 

Carbonic acid (CO,) 

Deduct oxygen equivalent to CI 
Total 



55-94 
0.31 

4-43 
3-78 
0-95 
0.80 

0-39 
0-40 
2.66 r 
8.64 
21 .60 



99.90 
.09 



99.81 



Potassium carbonate (K^COj)... 
Potassium phosphate (K3PO,). .. 

Sodium chloride (NaCl) 

Calcium sulphate (CaSO,) 

Calcium o.xide (CaO) 

Magnesium phosphate (MgjP^O,) 

Magnesium o.xide (MgO) 

Ferric oxide (Fe^Oj) 

Aluminum oxide (AUOj) 

Silica (SiOj) ". 



Total. 



6.85 

14 -SS 
0.60 

4-52 
2-S7 
6.97 
0.59 

0-9S 
0.80 
0.40 



99.80 



552 FOOD INSPECTION AND /1N/ILYSIS. 

Burcker* gives the following composition of the ash of cider: 

Per Cent. 

Silica 0.94 

Phosphoric acid 12.68 

Lime 2.77 

Magnesia 2 .05 

Oxides of iron and manganese o . 94 

Potash 53.74 

Soda 1 . 10 

Carbonic acid 25 . 78 



100.00 



Adulteration of Cider. — The Committee on Standards of the A. O. A. C. 
have submitted for adoption the following standards for cider: Alcohol 
not more than 8%, extract not less than 1.8% determined by evaporation 
in an open vessel at ordinary atmospheric pressure and at the tempera- 
ture of boiling water; ash not less than 0.2%. 

Entirely factitious cider made from other than apple stock is rarely 
found, though the product as sold is frequently of inferior quality and 
adulterated. The chief adulterants are water and sugar, and the use of 
antiseptics is common, especially of salicylic and sulphurous acids, and 
occasionally beta-naphthol. 

Sodium carbonate is sometimes added to cider to neutralize the acid 
and thus prevent acetic fermentation. An abnormally high ash (say 
in excess of 3-5%) would point toward the presence of added alkali. 

Watering is apparent when the content of alcohol, solids, and ash of 
the suspected sample are found to be considerably below the corre- 
sponding constants of pure cider. According to Sangle Ferriere, the 
following are the minimum figures for these constants in a pure cider, 
so that a sample may safely be pronounced as watered if they all 
run distinctly below; 

Alcohol 3% by volume 

Extract 1.8% 

Ash 0.17% 

Besides these determinations, it is useful also to determine the fixed 
and volatile acids. 

Caramel is to be looked for, especially in watered samples. Other 

* Les Falsifications des Substances Alimentaires, p. 176. 



ALCOHOLIC BEyERAGES. 



5S3 



adulterants alleged to be of frequent occurrence in French cider, but 
not commonly found in this country are commercial glucose, tartaric acid 
(to increase the acidity of a watered product), and coal-tar colors. 

Absence or deficiency of malates is conclusive evidence of fraud, 
indicating the admixture of notable quantities of the juice of the second 
pressing of pomace. 

Sugar is rendered apparent by the right-handed polarization of the 
sample, pure cider always polarizing well to the left. If after inversion 
of a dextro-rotary cider the polarization is still to the right, commercial 
glucose is indicated; if the reading after inversion is to the left, cane 
sugar has undoubtedly been added. 

Frequently the analyst has only to determine the alcohol, especially 
in cases of seizure, to ascertain whether or not there has been violation 
of the liquor laws. 

PERRY OR PEAR CIDER. 

This is a common French product, but is rarely if ever found on sale 
in this country, though sometimes made for home consumption. In 
composition and in method of manufacture it much resembles apple 
cider. It is also subject to the same forms of adulteration. 

The following table summarizes a number of analyses made by 
Truelle on pear juice, or must, amounts being expressed in parts per 
thousand : 



Specific gravity 

Invert sugar 

Sucrose 

Total fermentable sugars (as dextrose) . . 

Tannin 

Pectin and albuminous substances 

Acidity (as sulphuric acid) 



Mean. 



1.0845 

145.64 

.^6.74 

184.14 

1.78 

13.0S 

1-47 



Maximum. 



1.0675 
108.10 
16.60 

143-78 
1. 01 

3 
0.76 



M 



inimum. 



I . 0980 
200 

61 .41 
220 
^.20 
18 
2.40 



The following analysis of champagne perry is taken from the Lancet 
of October i, 1892: 

Alcohol by weight i - 45 

Alcohol by volume i . 80 

Solids II .00 

Ash 0.35 



554 FOOD INSPECTION /tND ANALYSIS. 



WINE. 



Wine in its broadest sense is the fermented expressed juice of any 
fruit, though the term, unless otherwise restricted, is generally understood 
to apply to the juice of the grape. 

The organism present in grape juice that plays the chief part in its 
alcoholic fermentation is the Saccharomyces ellipsoideus, a yeast which 
exists on the skins of the grape. 

Process of Manufacture. — The grapes, which should be fully ripe, 
are picked and sometimes sorted, according to the care that is taken in 
grading the product. They are also sometimes freed from the stems, 
which contain tannin and tartaric acid, and which when crushed with the 
grapes impart a certain astringency to the final product. The grapes are 
crushed cither by machinery or by the bare feet, and the juice is pressed 
out from the pulp in various ways, by screw or hydraulic press, or by the 
centrifugal process. 

A certain amount of juice runs ofif from the preliminary crushing 
known as the first run, and makes the choicest wine. The product from 
the pressure constitutes the second run, after which the pomace, by steep- 
ing in water and repressing, is made to yield an inferior juice used in 
vinegar-making. 

Red wines are made from dark grapes by fermenting the pulp, before 
pressing, with the skins, which by this treatment yield up their rich color 
(cenocyanin) to the juice. Besides the color, the skins contain also tannin. 
White wine is made from the pressed pulp, freed from the skins at once, 
or from the pulp of white grapes. The unfermented must constitutes 
from 60 to 80 per cent of the weight of the grape. 

Fermentation progresses most rapidly at a temperature between 25° 
and 30° C, but wine having a much finer bouquet is produced by slower 
fermentation, hence the must is allowed to ferment in open vats or tubs 
in cool cellars, at a temperature of from 5° to 15° till it settles out com- 
paratively clear, special care being taken to avoid development of acetic 
fermentation. At the end of the first or active fermentation, the wine 
is drawn off and allowed to undergo a second or slow fermentation in 
casks, during which most of the lees or crude argols, composed of potas- 
sium bitartrate, settle out, being insoluble in alcohol, and the characteristic 
bouquet or flavor of the wine is developed. Occasionally during this 
process the wine is racked or drawn off. 

Undesirable fermentations and vegetable fungus growth, which are 



ALCOHOLIC BEl^ERAGES. 555 

liable to occur at this time, are avoided as much as possible by using 
especially clean casks, which are frequently "sulphured" (or burnt out 
with sulphur) before being used. The wine is also sometimes clarified, 
or "fined," by treatment with gelatin, which mechanically removes many 
impurities by precipitation, or is subjected to pasteurization before finally 
being bottled or stored in casks. 

Classification of Wines. — Wines are either natural or jortified. Nat- 
ural wines are those whicli contain no added sugar or alcohol, but which 
are exclusively the product of the simple juice, fermented under the best 
conditions, either till the sugar has been used up, or till the yeast food 
is exliausted, or until tlie yeast growth has been checked by the strength 
of 'the alcohol developed. When the alcohol content amounts to 14% 
by weight there can be no further fermentation due to yeast, so that this 
is the highest limit for natural wine. Examples of natural wines are 
hock and claret and many California wines. 

Fortified wines are those to which alcohol has been added, usually before 
the natural fermentation has been allowed to proceed to a finish. For 
this reason considerable sugar is usually left, and such wines are more 
often sweet. Examples of fortified wines are Madeira, sherry, and port. 

Volatile ethers (products of volatile acids) predominate as a rule in 
natural wines, while fixed ethers (from the fixed acids as tartaric) are 
most characteristic in fortified wines. 

Wines are also variously classified according to characteristic proper- 
ties possessed by them, as still or sparkling, red or white, "dry" or sweet, 
etc. 

Still wines are those in which there is but little carbon dioxide remain- 
ing, so that they do not effervesce. Sparkling wines are more or less 
heavily charged with carbon dioxide, either naturally, as in the case of 
champagne, wherein the gas is formed by after-fermentation of added 
sugar in the corked bottle, or artificially, by carbonating them in a similar 
manner to "soda-water." 

Among the best-known red wines are those of Burgundy and the 
Bordeaux wines or clarets, while the Rhenish and Moselle wines and the 
Sautemes are examples of white wine. 

"Dry" wines are those in which the sugar has been exhausted by 
fermentation, while sweet wines possess a considerable amount of unfer- 
mented sugar. Whether or not an excess of sugar is left after fermenta- 
tion has stopped depends upon the amount of yeast food or nitrogenous 
substance present in the wine. When the proteids are exliausted by the 



556 



FOOD INSPECTION ^ND ANALYSIS. 



yeast, fermentation ceases, and for this reason gelatin and other nitrog- 
enous bodies are sometimes added to extend the period of fermentation. 
Sweet wines are often reinforced by the addition of sugar. Madeirsa, 
both red and white, are samples of dry wine, while port wine is one of 
the sweet variety. 

WTiile most of our finer wines still come from France and Germany, 
large quantities of California wines are now being produced of an extremely 
high grade and of many varieties. 

Composition of Grape Must and of Wine. — Konig's analyses of a 
large number of grape musts from different sources are thus summarized: 





Specific 
Gravity. 


Water, 
Per Cent. 


Nitroge- 
nous Ma- 
terial. 


Sugar. 


Acid. 


Other 
Non-ni- 
trogenous 
Material. 


Ash. 




i.o6go 
1.2075 
I .1024 


51-53 
82.10 

74-49 


O.II 

°-57 
0.28 


12.89 

35-45 
19.71 


0.20 
1. 18 
0.64 


1.68 

11.62 

4.48 




Maximum 


0.63 
0.40 


Mean 





Typical analyses of German, French, Austrian, Russian, Italian, and 
Spanish wines are shown in the following table, also due to Konig: 







*j 


x.2f 

01 


1 


e2« 




is 




1 


Germany: 

Moselle 


14 
=3 
46 

15 
6 

15 
10 

29 

5 

60 
>7 

10 
12 
20 

7 
4 


. 9964 
I - 0005 

0-9995 

0.9967 

0.9982 
0.9963 

0.9940 
0.9927 

0-9939 
0-9931 

1-0233 


7-99 
8.00 
6.65 
6.10 
4-73 
6-59 
8.08 

7.80 
8.30 

9.08 
8.84 

10.76 
11.96 
10.61 

12.30 
12.78 


2.24 
2.60 
2.16 
2.27 
2.64 
2.07 
2.27 

2.56 
3-03 

2.34 
1.87 

2.76 

2.568 

3-44 

3-53 
9.69 


0-79 
0.81 
0.91 

0-95 
1. 14 
0.696 
0.56 

0-57 
0.66 

0.62 
0-S9 

0.56 
0.49 
0-52 

0.49 
0-59 








0.031 


Rhine 


0.018 

0-095 
0.091 
0.018 
0.032 


0.20 

0.358 
0.262 
0.026 
0.168 


0.052 

0-IS5 


Baden 


0.095 


Wurtemburg, white wine. 

* ' red wine . . 

Alsace 


Lorraine, red wine 

France: 


0.088 
0.30 








0.142 

O.IOO 


Austria: 

Tyrol, red wine 




'■ white wine 

Russia: 










0.458 
1.44 

0.38 

6-55 


Italy 






Spain: 

Ordinary red wine 























/tLCOHOLlC BEyERAGES. 



557 





■§ 

5 


s 


< 


i 





E 
3 






■c 

3 . 

S-V, 


1 



S 


Germany: 


0.72 
0-85 
0.49 

0-57 
0.4C1 

0-55 
0.50 

0-73 
0.97 

0.65 
0.65 

0.64 
0-S9 

0-45 

1.09 
0.63 


0.028 
0.019 

0.043 

0.021 
0.020 

0.036 

0.026 


0-175 

0.23 

0.207 

0.25 

0.25 

0.229 

0.185 

0.248 
0.25 

0.222 
0-175 

0.267 
0.204 
0.29 

0.61 
0.74 


0.036 
0.046 
0.025 

0.043 
0.040 
0.038 
0.030 

0.030 
0.032 

0.027 
0.022 

0.027 
0.030 
0.032 

0.027 
0.039 


0.068 
0.085 

O.II5 
0.108 


O.OII 

0.017 


0.02 
0.022 


0.012 
0.020 

0.009 

0.08 

0.008 

0-033 
0.038 

0.023 
0.023 

0.019 

0.221 
0.212 




Rhine 




Baden 




Wurtemburg, white wine. 

' ' red wine. . 

Alsace 


0.021 


0.024 


O.OIO 








France: 

Red wine 


0.106 
0.098 


O.IOI 
O.OIO 


0.018 
0.015 








Austria: 




' * white wine .. . 


0.077 

O.III 
0.086 
0.115 

0.242 
0.296 








Russia: 

Red wine 


0.009 
0.008 


0.017 








Italy 




Spain: 

Ordinar)' red wine 

Sweet wine 













On page 558 are given summaries of analyses of American wines 
compiled from tables of analyses made by Bigelow.* 

Varieties of Wine. — Champagne is a selected, sweet, white wine, 
clarified with gelatin, bottled with the addition of cane sugar, mixed with 
a little brandy, and tightly corked. Sometimes a small amount of yeast 
is also introduced. Fermentation is allowed to go on at a temperature 
of about 24° C, during which the wine is highly charged with carbon 
dioxide. The bottles are set on their side for some months, after which 
they are inverted till the sediment gathers above the cork, which by careful 
manipulation is quickly removed so as to throw out the sediment, and is 
afterward replaced and secured. Champagne contains from 8 to 10 
per cent of alcohol and is high in sugar. 

Clarci is a light, red wine of a deep color, and is somewhat acid and 
astringent. In alcohol it varies from 8 to 13 per cent by volume. It has 
very little sugar and is high in volatile ethers. 

Madeira is a strong, white wine, possessing a refined, nutty, aromatic 
flavor when fully aged. It is generally fortified, containing from 17 to 
20 per cent of alcohol. It is named from the island which produces it. 

Sherry is a deep, amber-colored, sweet, Spanish wine, high in alcohol 

* U. S. Dept. of Agric, Bur. of Chem., Bui. 59. 



55« 



FOOD INSPECTION /1ND ANALYSIS. 






•qsv 



pUE illUUBJ, 



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uinissE:iOjj 



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Supnpay 



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rOO NM f^M rJ-M 



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/ILCOHOLIC BEyERAGES. 559 

(sometimes containing over 20%), being usually fortified. It is slightly 
acid and possesses much fragrance. Sherry is nearly always "plastered." 

Hocks are white German wines, mildly acid, containing 9 to 12 per 
cent of alcohol by volume. They have very little sugar, and rank among 
the highest of natural wines. The best-known varieties are Hockheimer 
and Johanisberger. 

Port (Vinum portense of the 1870 Pharmacopoeia) is a dark-purple, 
astringent wine, almost always fortified, and hence high in alcohol (from 
15 to 18 per cent by volume). It is much improved by aging, during 
which it looses considerable of its astringency. It contains a large amount 
of extract, from 2 to 6 per cent of the wine being sugar. The fixed ethers 
predominate over the volatile. 

Standards of Purity for Wine. — The ratio of volatile to lixed acids in 
pure wine should not exceed 1:3. A higher proportion of volatile acid 
shows the fact that acetic fermentation has set in. 

The presence of any considerable free tartaric acid would indicate 
the addition of this substance to the wine. 

The United States Pharmacopoeia has prescribed the following require- 
ments in the case of wines: For white wine (Vinum album) the specific 
gravity at 15.6° should not be less than 0.990 nor more than i.oio; the 
extract or residue at 100° should not be less than 1.5 nor more than 3%; as 
indicating the amount of free acid, not less than 3 nor more than 5.2 cc. 
normal potassium hydroxide should be required to neutralize 50 cc. of 
the wine, using phenolphthalein as an indicator; it should contain not less 
than 10 nor more than 14 per cent by weight of absolute alcohol; it should 
contain only traces of tannin. 

For red wine [Vinum rubiim) the specific gravity at 15.6° should not 
be less than 0.989 nor more than i.oio; the extract should not be less 
than 1.6% nor more than 3.5%; its limits as to acidity are the same as 
with white wine, eosin or fluorescin, however, being used as an indicator; 
in alcoholic strength, it should, like white wine, come within the limits 
of 10 and 14 per cent alcohol by weight. It should not be artificially 
colored, but should show the presence of tannic acid. 

The following standards have been recently suggested for adoption 
by the A. O. A. C. by its Committee on Standards: In white wine the 
extract should be not less than 1.5 and not more than 4 per cent; in red 
wine the limits are 1.6 and 4 per cent. For both red and white wine 
the alcohol should not be more than 16% by volume and the ash not 
less than 0.14%. For fortified sweet wine the extract should be not less 



560 FOOD INSPECTION AND ANALYSIS. 

than 6%, except in case of sherries, which should contain not less than 
3%, and the alcohol should not be more than 24 nor less than 14 per 
cent by volume. 

Adulteration of Wine. — Beverages purporting to be wine are some- 
times found on sale that are entirely spurious, in that they contain little 
if any fermented grape juice. Apple cider is not infrequently the basis 
of such artificial products, and the following recipes given by Brannt 
may be taken as typical of the composition of these wine substitutes: 

Burgundy. — Bring into a barrel 40 quarts of apple juice, 5 pounds 
of bruised raisins, \ pound of tartar, i quart of bilberry juice, and 3 
pounds sugar. Allow the whole to ferment, filling constantly up with 
cider. Then clarify with isinglass, add about i ounce of essence of bitter 
almonds, and after a few weeks draw off into bottles. 

Malaga Wine. — x^pple juice, 40 quarts; crushed raisins, 10 pounds; 
rectified alcohol, 2 quarts; sugar solution, 2 quarts; elderberry flowers, 

1 quart; acetic ether, i ounce and 2 drachms. The desired coloration is 
effected by the addition of bilberry or elderberry juice; otherwise the 
process is the same as given for Burgundy. 

Sherry Wine. — Apple juice, 50 quarts; orange-flower water, about 

2 drachms; tartar, 2 ounces and 4 drachms; rectified alcohol, 3 quarts; 
crushed raisins, 10 pounds; acetic ether, i ounce and 2 drachms. The 
process is the same as for Burgundy. 

Claret Wine. — Apple juice, 50 quarts; rectified alcohol, 4 quarts; 
black currant juice, 2 quarts; tartar, 2 ounces and 4 drachms. Color 
with bilberry juice. The further process is the same as for Burgundy. 

Artificial products similar in nature to the above are also mi.xed in 
var\'ing proportions with pure wine. 

Presence of malates, as well as absence or diminution of total tartaric 
acid, is also indicative of cider. 

If the ash of the wine be submitted to the flame test, the sodium light 
will predominate in the case of pure wine, while if the basis of the sample 
be largely or wholly apple stock, the potash flame will be readily apparent. 

Wines are most frequently adulterated by "plastering," by watering, 
by the addition of excessive amounts of sugar or glucose, by various flavor- 
ing principles, by coal-tar and vegetable colors, by antiseptics, and by 
added alcohol. 

Plastering.— By this term is understood the addition of gypsum or 
plaster of Paris to the must before fermentation, a practice in vogue in 
parts of France, Italy, and Spain. The reaction which takes place with 



ALCOHOLIC BEVERAGES. 



561 



the potassium bitartrate present in the wine is, according to Chancel, 
as follows: 

2KHC,H,Oe + CaSO, = CaC,H,Oe+H,C,HPe+K2SO,. 

Potassium Calcium Calcium Tartaric Potassium 

bitartrate sulphate tartrate acid sulphate 

Various advantages are said to result from this practice. The wine 
is clarified by the precipitation of the calcium tartrate, which mechan- 
ically carries down with it many impurities, the color of the wine is 
improved, since the solubility of the coloring principle present in the 
skins is increased, the fermentation is rendered more rapid and complete, 
and the keeping qualities of the wine are enhanced. The practice is, 
however, considered objectionable on account of the potassium sulphate 
which is left in solution in the wine, and in some countries plastering 
is forbidden, or the amount of potassium sulphate limited by statute. 

The following are analyses of two Spanish wines made from the same 
grape juice, one of which was plastered. The results are expressed in 
grams per liter. 





Not Plastered. 


Plastered. 


Color 


Yellow 

23-3 
0.66 
2.06 

1.29 
0.41 


Bright red 

= 7-3 
0.61 

5-38 

0.17 

5 


Extract dried at 100° 


Soluble ash. 


The soluble ash containing 

Potassium carbonate . . . 

" sulphate. 



The effect of plastering is thus seen to distinctly increase the extract 
and the soluble ash. Any considerable amount of potassium sulphate 
is an indication of plastering. 

Addition of Cane Sugar. — The term " chaptalizing " is applied in 
France to the addition to the must of cane sugar for the purpose of 
increasing the yield in alcohol. The addition of 1,700 grams of sugar 
to 1,000 liters of must is said to increase the alcoholic strength by 1%. 
It ■ was formerly customary to add with the sugar calcium carbonate, 
to partially neutralize the acidity, but this is rarely practiced at present. 

The European wine-raising countries are not disposed to regard the 
reinforcement of wine by added cane sugar in the must as in itself a fraud, 
unless water is also added, or unless some other form of adulteration is 
practiced at the same time. Its use is even favored in France, to the 



562 FOOD INSPECTION AND ANALYSIS. 

extent that there is a reduction in duties on cane sugar used for this 
purpose. 

The use of commercial glucose in wine instead of cane sugar is not 
regarded with as much favor, in view of the fact that glucose contains 
more or less unfermentable matter, and introduces dextrin and various 
mineral salts into the wine. 

To ascertain the nature and extent of the sugars present in wine is 
frequently of great importance. Much information may be gained from 
the direct and invert polarization of the sample, as well as from the deter- 
mination of reducing sugars. 

Invert sugar is the only legitimate sugar that should be present in 
genuine wine. In normal fermentation the dextrose is more quickly 
destroyed than the levulose, hence the polarization of pure wine is always 
left-handed, unless all the sugar has been fermented, in which case the 
reading should be zero. 

Seventy-five samples of California red wines, chiefly claret, Burgundy, 
Rhine, and southern France types, analyzed in the Bureau of Chemistry * 
of the U. S. Department of .\griculture, polarized from —0.5 to —2.1. 
Upwards of eighty samples of California white wine (of the types of 
Burgundy, Sauteme, and southern France) were submitted to polariza- 
tion and all but four were left-handed. These four (evidently abnormal) 
polarized from o. to -f-i. Most of them varied from — o.i to —3.5. 

Thirteen of the port wine types (California) had a left-handed polariza- 
tion of from —14.7 to —27.1. These apparently contained large quan- 
tities of unfermented, inverted cane sugar. 

A sharp, right-handed polarization would indicate the presence of 
either commercial glucose or cane sugar. After inversion, if the reading 
is still right-handed, glucose is apparent, while if inversion changes the 
reading from right to left, cane sugar has undoubtedly been added. By 
application of Clerget's formula the amount of cane sugar can be estimated. 

The Watering of Wine, unless excessive in degree, is not always easy 
to prove, by reason of the varying composition of pure wine, and because 
the practice is usually accompanied by other forms of sophistication 
intended to cover up evidences of watering. Considerable quantities 
of added water alone would usually be rendered apparent by a propor- 
tionate and abnormal lowering of the alcohol, extract, ash, acidity, and, 
indeed, nearly all the constants. 

Gautier in his Traite sur la Sophistication et I' Analyse des Vins claims 

* Bui. 59. 



ALCOHOLIC BEy BRACES. S^i 

that the sum of the weight in grams of alcohol in loo cc. and the total 
acidity, expressed in grams of sulphuric acid per liter, varies within very 
narrow limits in pure wines, rarely being below 13 or above 17. A large 
number of analyses made by Gautier and others would seem to confirm this, 
so that in the majority of cases, added water would be strongly indicated if 
the sum of these two constants was materially reduced below 13. It is 
more conservative to adopt 12.5 as a minimum limit for the sum of the 
alcohol and total acid expressed as above. 

Detection of Added Alcohol. — As a result of the findings of a com- 
mittee appointed in France to determine the matter of added alcohol, 
it was submitted that a relation existed between the weight of the extract 
and that of the alcohol in pure wine. In the case of red wines, if the 
weight of the alcohol, divided by the weight of the extract (both expressed 
in grams per 100 cc.) exceeds 4.6, the addition of alcohol is strongly indi- 
cated. With wliite wines, the quotient obtained by dividing the weight 
of alcohol by weight of extract should not exceed 6.6. If it does, added 
alcohol is to be suspected. 

In the case of plastered wines containing sulphate of potassium, or 
wines having added sugar, it is necessary to deduct from the total extract 
the weight of the reducing sugar and of the potassium sulphate as found 
(less 0.1 gram for each of these substances), the difference, or reduced 
extract as it is called, being used in this case in obtaining the ratio. 

Fruit Wines other than Grape. — Wines mostly of domestic manufac- 
ture are sometimes made from small fruits, such as raspberries, straw- 
berries, blackberries, gooseberries, elderberries, and currants, as well as 
from cherries, plums, and apricots. Wines made from most of these 
fruits readily undergo acetic fermentation unless antiseptics are added, 
or unless extreme care is taken in their manufacture and keeping. Fre- 
quently mixtures of various fruit juices are made to yield excellent wine. 
Most of the sour fruits require a liberal admixture of sugar to produce 
an acceptable wine. 

The following analysis of current wine is due to Fresenius: 

Alcohol -, 10.01% 

Free acid o . 79% 

Sugar 11.94% 

Water 77 . 26% 

The alcoholic content of other fruit wines is thus shown by Brannt: 

Gooseberry wme 11 .84% alcohol 

Elderberry wine 8 . 79% ' ' 

Orange wine 11.26% " 



564 FOOD INSPECTION AND ANALYSIS. 

Methods of Analysis of wine and Cider. — For determination of 
specific gravity, alcohol, extract (by direct method), and ash see pp. 527, 

528, and 547- 

Calculation of the Extract in Wine. — Attention has already been called 
to the difficulty in accurately determining the extract of sweet wines 
gravimetrically by evaporation. An ap proximate determination of the 
extract may be obtained by calculation from the specific gravity of the 
dealcoholized liquor, or one may use for this purpose the tables compiled 
by Windisch, and based on experiments made on drying wine in vacuo at 
75° C. In wines high in sugar, containing more than 6% of extract, 
this method is far more accurate than that of drj'ing at 100°, and is to be 
recommended. 

Evaporate a measured portion of the wine on the water-bath to 
one-fourth its volume, and dilute with water to exactly the volume 
measured. Determine the specific gravity of this dealcoholized liquid 
at 15.6°, and from the following table ascertain the extract corre- 
spondmg. 

Determination of Total Acidity. — Carbonated beverages are first 
freed from carbon dioxide by agitation as described on page 528, after 
which 25 cc. of the sample are heated just to the boiling-point and titrated 
with tenth-normal sodium hydroxide, using in the case of white wine 
or cider phenolphthalein as an indicator. With red wine delicate litmus- 
paper should be used. Total acidity is usually expressed, in the case 
of cider as malic, and of wine as tartaric acid. Each cubic centimeter 
of tenth-normal alkah corresponds to 0.0067 gram malic, or 0.0075 gram 
tartaric acid. Some chemists express total acidity in terms of sulphuric 
acid, each cubic centimeter of tenth-normal allcali being equivalent to 
C.0049 gram of sulphuric acid. 

Volatile Acids in all liquors are usually expressed as acetic, although 
traces of propionic and other volatile acids may be present. 50 cc. of 
the cider or wine and a little tannic acid are transferred to a distilling- 
flasli. Fig. 114, the stopper of which is provided with two tubes, one of 
which connects with the condenser, while the other, arranged to reach 
nearly to the bottom of the distilling-fiask, communicates with a second 
flask which contains about 300 cc. of water. The contents of both flasks 
are brought to boiling, after which the flame under the distilling-flask 
is lowered, and steam from the water-flask is passed through the wine 
till about 200 cc. of distillate have collected in the receiving-flask. 
Titrate this with tenth-normal sodium hydroxide, using phenolphthalein 



ALCOHOLIC BEyER/IGES. 



565 



EXTRACT IN WINE. 
[According to Windisch.] 



Specific 


Ex- 


Specific 


Ex- 


Specific 


Ex- 


Specific 


Ex- 


Specific 


Ex- 


Specific 


Ex- 


Gravity. 


tract. 


Gravity. 


tract. 


Gravity. 


tract. 


Gravity. 


tract. 


Gravity. 


tract. 


Gravity. 


tract. 


I .0000 


0.00 


I .0065 


1.68 


I .0130 


3.36 


I. 0195 


5.04 


I .0260 


5.72 


1 .0325 


8.40 


I .0001 


0.03 


I .0066 


1.70 


1.0131 


3.38 


1 .0196 


5.06 


I .0261 


6.75 


1 .0326 


8.4t 


I .0002 


0.05 


I .0067 


1.73 


I .0132 


3-41 


I .0197 


S.09 


I .0262 


6.77 


I .0327 


8.46 


I .0003 


0.08 


I .0068 


1.76 


I. 0133 


3-43 


I .0198 


S. II 


1.0263 


6.80 


1.0328 


8.48 


1 .0004 


0. 10 


I .0069 


1.78 


I. 0134 


3.46 


I .0199 


5. 14 


1.0264 


6.82 


1.0329 


8.51 


I .000s 


0.13 


I .0070 


1. 81 


I. 0135 


3.49 


1 .0200 


S.17 


I .0265 


6.85 


I 0330 


8.53 


I .0006 


0.15 


1 .0071 


..83 


I .0136 


3.51 


I .0201 


5.19 


I .0265 


5.88 


I. 0331 


8.56 


1 .0007 


0.18 


I .0072 


1.86 


I. 0137 


3.S4 


I .0202 


5.22 


I .0267 


6.90 


1 .0332 


8.59 


1 .0008 


0. 20 


1.0073 


1.88 


I .0138 


3. 56 


I .0203 


5.25 


I .0268 


6.93 


1.0333 


8.61 


I ,0009 


0.23 


1.0074 


1. 91 


I. 0139 


3. 59 


I .0204 


5.27 


I .0269 


6.9s 


1.0334 


8.64 


I .0010 


0.26 


1.0075 


1.94 


I .0140 


3.62 


1.0205 


S.30 


1 .0270 


6.98 


1.033s 


8.66 


1 .0011 


0.28 


I .0076 


1 .96 


I .0141 


3.64 


I .0206 


5-32 


I .0271 


7.01 


I .0336 


8.69 


I .0012 


0.31 


1.0077 


1.99 


I .0142 


3.67 


I .0207 


5-35 


I .0272 


7.03 


I.0337 


8.72 


1 .0013 


0.34 


1.0078 


2.01 


I. 0143 


3.69 


I .0208 


5.38 


I .0273 


7 .o5 


1.0338 


S.74 


1 .0014 


0.36 


1.0079 


2.04 


I. 0144 


3.72 


I .0209 


5. 40 


1.0274 


7.08 


1.0339 


8.77 


I -oois 


0.39 


I ,ooSo 


2.07 


1.014s 


3-75 


I. 0210 


5-43 


I .0275 


7. II 


1.0340 


8.79 


I .0016 


0.41 


I .0081 


2.09 


I .0146 


3.77 


I .0211 


5.4s 


I .0276 


7; 13 


I 0341 


8.82 


I .0017 


0.44 


I .0082 


2.12 


I. 0147 


3.80 


1.0212 


S.48 


I .0277 


7.i5 


I .0342 


8.8s 


I .0018 


0.46 


I .0083 


2.14 


I .0148 


3.82 


I .0213 


5. SI 


1.0278 


7.19 


1.0343 


8.87 


l.ooig 


0.49 


I .0084 


2.17 


I. 0149 


3.85 


I .0214 


5.53 


1.0279 


7.21 


1.0344 


8.90 


I .0020 


O.S2 


I .0085 


2.19 


I .0150 


3.87 


I .0215 


5.S6 


I .0280 


7.24 


1.0345 


8.92 


I .0021 


0.54 


I .0086 


2.22 


I .0151 


3.90 


I .0216 


s.ss 


I .0281 


7.26 


1.0346 


8.95 


1 .0022 


0.57 


I .0087 


2.25 


I .0152 


3.93 


1 .0217 


5. 61 


I .0282 


7. 29 


I .0347 


8.97 


1 .0023 


0.59 


1.0088 


2.27 


I. 0153 


3-95 


1 .0218 


S.64 


I .0283 


7.32 


1.0348 


9.00 


1.0024 


0.62 


1.0089 


2.30 


I. 0154 


3.98 


I .0219 


S.66 


I .0284 


7-34 


1.0349 


903 


I. 002s 


0. 64 


I .0090 


2.32 


I.OI5S 


4.00 


I .0220 


5.69 


1.028s 


7.37 


1.0350 


9.05 


I .0026 


0.67 


I .0091 


2-35 


I .0156 


4.03 


I .0220 


5.71 


1.0286 


7-39 


I .0351 


9.08 


I .0027 


0.69 


I .0092 


2.38 


I.OIS7 


4.06 


I .0222 


S.74 


I .0287 


7.42 


1.0352 


9. lo 


I .002S 


0.72 


I .0093 


2.40 


I. 0158 


4.0S 


I .0223 


5-77 


1.028S 


7.45 


I 0353 


9.IJ 


I .0029 


0.75 


I .0094 


2.43 


I.01S9 


4. II 


I .0224 


5-79 


1 .02S9 


7.47 


1.0354 


9.15 


1.0030 


0.77 


I .0095 


2.45 


I .0160 


413 


I .0225 


S.82 


I .0290 


7.50 


I.0355 


9.1S 


I .0031 


0.80 


I .0096 


2.48 


r .0161 


4.16 


1 .0226 


S.84 


I .0291 


7-52 


I .0356 


9.21 


I .0032 


0.82 


I .0097 


2.50 


I .0162 


4. 19 


I .0227 


5. 87 


1 .0292 


7.55 


1 .0357 


9.2J 


I .0033 


0.8s 


I .0098 


2.53 


I .0163 


4.21 


I .022S 


5.89 


1.0293 


7.58 


1.0358 


9. 26 


1.0034 


0.87 


I .0099 


2.56 


I .0164 


4.24 


I .0229 


S.92 


I .0294 


7.50 


I 0359 


9.29 


1.0035 


0.90 


I .0100 


2.58 


I .0165 


4. 26 


I .0230 


594 


1.029s 


7.63 


I .0360 


9-31 


I .0036 


0.93 


I .0101 


2.6l 


I .0166 


4.29 


I .0231 


S.97 


1 .0296 


7.6s 


I .0361 


9-34 


1.0037 


0.95 


1 .0102 


2.63 


I .0167 


4-31 


I .0232 


6.00 


I .0297 


7.68 


I .0362 


9.36 


I .0038 


0.98 


I .0103 


2.66 


I. 0168 


4-34 


1.0233 


6.02 


I .0298 


7.70 


1.0363 


9.39 


1.0039 


I .00 


I .0104 


2.69 


1.0169 


4-37 


1.0234 


6.05 


1.0299 


7-73 


1.0364 


9.42 


I . 0040 


I.03 


I .0105 


2.71 


I .0170 


4-39 


I.0235 


6.07 


I .0300 


7.76 


1.0365 


9.44 


I. 0041 


I. OS 


I .0106 


2.74 


I .0171 


4.42 


I .0236 


6. 10 


I .0301 


7.78 


I .0366 


9.47 


I .0042 


1 .08 


I .0107 


2.76 


I .0172 


4-44 


1.0237 


6.12 


I .0302 


7.81 


I .0367 


9.49 


1.0043 


I . II 


I .0108 


2.79 


I. 0173 


4-47 


1.0238 


6.15 


1.0303 


7.83 


1.0368 


9.52 


I . 0044 


I-I3 


I .0109 


2.82 


I. 0174 


4SO 


1.0239 


6.18 


1.0304 


7.86 


I- 0369 


9-55 


1.0045 


1. 16 


I .0110 


2.84 


I .017s 


4.52 


I .0240 


6.20 


1.0305 


7.89 


1.0370 


9.57 


I . 0046 


1. 18 


I.OIII 


2.87 


1 .0176 


4.55 


I .0241 


6.23 


I .0306 


7.91 


I .0371 


9 . 60 


1.0047 


1 .21 


I.OII2 


2.89 


I .0177 


4.57 


I .0242 


6.2s 


1.0307 


7.94 


1.0372 


9.62 


I .0048 


1.24 


I.OII3 


2.92 


I .0178 


4.60 


1.0243 


5.28 


I .0308 


7.97 


1.0373 


9.65 


J. 0049 


1.25 


I .0114 


2.94 


I. 0179 


4.63 


1.0244 


6.31 


I .0309 


7.99 


1.0374 


9.68 


I .0050 


1.29 


I .0115 


2.97 


I .0180 


4.6s 


1.024s 


6.33 


I .0310 


8.02 


I.0375 


9- 70 


I. 0051 


1-32 


I .0116 


3.00 


I .0181 


4.68 


I .0246 


6.36 


I .0311 


8.04 


I .0376 


9-73 


I .0052 


1-34 


I .0117 


3.02 


I. 0182 


4.70 


1.0247 


6.38 


I .0312 


8.07 


I .0377 


9.75 


I. 0053 


I -37 


I .0118 


3.05 


I. 0183 


4.73 


I .0248 


5.41 


I. 0313 


8.09 


1.0378 


9.73 


I.. 0054 


'■39 


I.0II9 


3.07 


I .0184 


4-75 


1.0249 


6.44 


1.0314 


8.12 


1.0379 


9.8a 


I .0055 


r.42 


I. 0120 


3.10 


1.01S5 


4.78 


1.0250 


6.46 


1.0315 


8.14 


1 .0380 


9.83 


I .0056 


1.45 


I .0121 


3.12 


I. 01 86 


4.81 


I .0251 


6.49 


I .0316 


8.17 


1.0381 


9.86 


I.OOS7 


1-47 


I .0122 


3. IS 


I .0187 


4.83 


I .0252 


6. SI 


I .0317 


8.20 


1.0382 


9.88 


1.0058 


i-So 


I .0123 


3.18 


I. 01 88 


4.85 


I .0253 


6.54 


1 .0318 


8.22 


1.0383 


9.91 


1.0059 


I.S2 


I .0124 


3.20 


I .0189 


4.88 


1.0254 


6.56 


I. 0319 


8.25 


1.0384 


9-93 


I .0060 


1-55 


I .0125 


3.23 


r .0190 


4.91 


I.0255 


6. 59 


I .0320 


8.27 


1.0385 


9.96 


1 .0061 


1-57 


I .01 26 


3.26 


I .0191 


4.94 


1 .0256 


6.62 


1.0321 


8.30 


1.0386 


9' 99 


1 .0002 


1.60 


I .0127 


3.28 


I .0192 


4.96 


I .0257 


6.64 


1 .0322 


8.33 


1.0387 


10.01 


I .0063 


:.63 


I .01 28 


3.31 


I. 0193 


4-99 


I .0258 


5.67 


1.0323 


8-35 


1.0388 


10.04 


I .0064 


1.65 


I. 0129 


i-ii 


I. 0194 


S-Oi 


1.0259 


5 . 70 


1.0324 


8.38 


1.0389 


10.06 



566 



FOOD INSPECTION AND ANALYSIS. 
EXTRACT IN WINE— (CoH/m«f(f). 



Specific 


Ex- 1 


Specific 


Ex- 


Specific 


Ex- 


Specific 


Ex- 


Specific 


Ex- 


Specific 


Ex- 


Gravity. 


tract. ! 


Gravity. 


tract. 


Gravity. 


tract. 


Gravity.' 


tract. 


Gravity. 


tract. 


Gravity. 


tract. 


1.0390 


10.09 


1 .0455 


11.78 


1.0S20 


13.47 


1-0585 


15. 16 


I .0650 


16.86 


1.071S 


18.56 


1.0301 


10. II [ 


1.0456 


11.81 


I .0521 


13-49 


1 .0586 


15.19 


I -0651 


16.88 


I .0716 


18.58 


J. 0392 


10.14 ■ 


1 -0457 


11.83 


I .0522 


13.52 


1.0587 


15. 22 


I -0652 


16.91 


1.0717 


18.61 


J.O303 


10. 17 


1 .0458 


11.86 


1.0523 


13-55 


1.0588 


15.24 


1-0653 


16.94 


1 .0718 


18.63 


1.0394 


10. 19 


1-04S9 


11.88 


1.0524 


13-57 


1.0589 


15-27 


I .0654 


16.96 


I. 0719 


18.66 


1.0395 


10. 22 


I .0460 


11 .91 


1.0525 


13.60 


1.0590 


1S.2P 


I .0635 


16.09 


I .0720 


18.69 


I. 0396 


10. 2S 


1.0461 


11-94 


I .0526 


13.62 


I.OS9I 


15.32 


1 .0656 


17.01 


I .0721 


18.71 


1 .0.197 


10. 27 


1 .0462 


II .96 


1.0527 


13.65 


I -0592 


15.35 


1 .0657 


17.04 


1 .0722 


18-74 


1.0398 


10.30 


I .0463 


11.99 


1.0528 


13.68 


1.0593 


is. 37 


I .0658 


17.07 


1 .0723 


18.76 


1.0399 


10.32 


1.0464 


12.01 [ 


1.0529 


13.70 


I.OS94 


15.40 


I .0659 


17.00 


1.0724 


18.79 


1 .0400 


10.35 


1.046s 


12.04 


1.0530 


13.73 


I. 0595 


15.42 


1 .0660 


17.12 


1.0725 


18.82 


1 .0401 


10.37 


1 .0466 


12.06 


1-0531 


13.75 


I .0596 


15.4s 


I .0661 


17.14 


1 .0726 


18.84 


I .0402 


10.40 


I .0467 


12.09 


1-0532 


13-78 


I.OS97 


15.48 


1 .0662 


17.17 


I -0727 


18.87 


I .0403 


10.43 


1.0468 


12.12 


I -0533 


13-81 


I .0598 


15.50 


I .0663 


17. 20 


1 .0728 


18.90 


I . 0404 


10.4s 


1.0469 


12.14 


I.OS34 


13.83 


1.0599 


15-53 


1 .0664 


17.22 


1.0729 


18.92 


I. 040s 


10.48 


1.0470 


12.17 


1-0535 


13.86 


1 .0600 


15-55 


I .0665 


17-25 


1.0730 


18.95 


I . 0406 


10.51 


I -0471 


12. 19 


1-0536 


13. 89 


1 .0601 


15.58 


I . 0666 


17-27 


1.0731 


18.07 


1.0407 


10.53 


1.0472 


12.22 


I-OS37 


13.91 


I .0602 


15.61 


1 .0667 


17.30 


1.0732 


19-00 


I .0408 


10.56 


1.0473 


12.25 


1-0538 


13-94 


1.0603 


15-63 


1.0668 


17.33 


1-0733 


19-03 


1.0409 


10.58 


1.0474 


12.27 


1.0S39 


13.96 


I .0604 


1S.66 


1.0669 


17.3s 


1-0734 


19.05 


I. 0410 


10.61 


1.0475 


12.30 


1.0540 


13.99 


I .0605 


15.68 


I .0670 


17.38 


1-0735 


19.08 


1 .0411 


10.63 


1.0476 


12.32 


I .0541 


14.01 


I .0606 


15-71 


I. 0671 


17-41 


I -0736 


19.10 


1 .0412 


10.66 


1.0477 


12. 3S 


1 .0542 


14.04 


1 .0607 


15-74 


I .0672 


17-43 


1 -0737 


19.13 


1 .0413 


10. 69 


1.0478 


12.38 


1 .0543 


14.07 


I .0608 


15-76 


1.0673 


17.46 


1.0738 


10-16 


1. 0414 


10.71 


1.0479 


12.40 


I. 0544 


14.09 


I .0609 


15.79 


1 -0674 


17.48 


1.0739 


19. 18 


1.041S 


10.74 


1.0480 


12.43 


I.OS45 


14.12 


I .0610 


15.81 


T.0675 


17.51 


1.0740 


19.21 


1 .0416 


10.76 


I .0481 


12.45 


1 .0546 


14.14 


I .0611 


iS-84 


I .0676 


17.54 


1 .0741 


l9-'23 


1 .0417 


10.79 


1.0482 


12.48 


1 .0547 


14. 17 


I .0612 


iS-87 


1.0677 


17-56 


1.0742 


19. 26 


1 .0418 


10. 82 


1 .0483 


12.51 


1.0548 


14. 20 


1 .0613 


15-89 


1.0678 


17-50 


1.0743 


19.29 


1.0419 


10.84 


1.0484 


12.53 


1.0549 


14.22 


I .0614 


15.92 


1 .0679 


17 .62 


1.0744 


10.31 


1 .0420 


10.87 


1.048s 


12.56 


1.0550 


14-25 


I. 0615 


IS. 94 


I .0680 


17.64 


1.0745 


10-34 


I .0421 


10.90 


1.04S6 


12.58 


1.0551 


14. 28 


I .0616 


15-97 


1.0681 


17.67 


1.0746 


10-37 


1 .0422 


10.92 


1.0487 


12.61 


1.0552 


14.30 


I .0617 


16.00 


1.0682 


17.69 


1.0747 


10-30 


1 .0423 


10.9s 


1.04SS 


12.64 


1-OSS3 


14-33 


I. 0618 


16.02 


I .0683 


17-72 


1.0748 


19.42 


1.0424 


10.97 


I .0489 


12.66 


1.0S54 


14-35 


I .0619 


16.05 


1 .0684 


17-75 


1.0749 


19-44 


1.042s 


11 .00 


I .0490 


1 2.69 


I-OS55 


14-38 


1 .0620 


16.07 


1.068s 


17.77 


1.0750 


10-47 


I .0426 


II .03 


I .o.'pt 1 12.71 


1 -0556 


14-41 


1 .0621 


16. 10 


1.0686 


17-80 


1 .0751 


19-50 


1.0427 


11.05 


1 .0492 


12.74 


1-0557 


14-43 


I .0622 


16.13 


1 1.0687 


17-83 


1.0752 


19-52 


1 .0428 


11.08 


1.0493 


12.77 


1-0558 


14.46 


I .0623 


16. 15 


1.0688 


17.85 


1.0753 


19-55 


1.0429 


11 . 10 


I .0494 


12.79 


I. 0559 


14.48 


I .0624 


16.18 


1 1.0689 


17.88 


1.0754 


19-58 


1 .0430 


11.13 


1.0495 


12.82 


I .0560 


14-51 


1.062s 


16. 21 


j I .0690 


17.90 


I-075S 


19.60 


1 .0431 


11.15 


1 .0496 


12.84 


1.0561 


14-54 


I .0626 


16.23 


1 .0691 


17.93 


1-0756 


19.63 


I -0432 


11.18 


I -0497 


12.87 


I .0562 


14-56 


I .0627 


16.26 


1 .0692 


17.9s 


1.0757 


10-65 


1.0433 


II . 21 


1 .049S 


12.90 


1.0563 


14-59 


1.0628 


16.28 


1 .0693 


17.98 


1.0758 


19-68 


1.0434 


11.23 


1.0499 


12.92 


1.0564 


14.61 


1 .0629 


16.31 


1 .0694 


18.01 


I -0759 


19-71 


I .0435 


II . 26 


1 .0500 


12.95 


1.056s 


14.64 


1 .0630 


16.33 


I -069s 


18.03 


1 .0760 


19-73 


I .0436 


11.28 


I .0501 


12.97 


1 .0566 


14.67 


I. 0631 


16.36 


1 .0696 


18.06 


1 .0761 


19-76 


I .0437 


11.31 


I -0502 


13-00 


1.0567 


14.69 


I .0632 


16.39 


I .0607 


18.08 


I .0762 


10-70 


1 .0438 


11.34 


1-0503 


13.03 


1.0568 


14.72 


1.0633 


16.41 


I .0698 


18.11 


1.0763 


l0-8l 


I .0439 


11 .36 


1.0504 


13.05 


I .0569 


14.74 


1.0634 


16.44 


I .0699 


18.14 


1.0764 


19-84 


I .0440 


11 .39 


1.0505 


13.08 


1.0570 


14.77 


1.0635 


16.47 


I .0700 


18.16 


1.076s 


19-86 


I .0441 


II .42 


I .0506 


13.10 


1-0571 


14.80 


' I .0636 


16.49 


1 .0701 


18. 19 


1 .0766 


10-80 


I .0442 


11-44 


1.0507 


13.13 


1.0572 


14.82 


1 I .0637 


16.52 


I .0702 


18.22 


I .0767 


19-92 


I .0443 


11-47 


I .0508 


13. 16 


1.0573 


14.8s 


1.0638 


16.54 


1.0703 


18.24 


1.076S 


19.94 


1.0444 


11.49 


I. 0509 


13.18 


I 1.0574 


14.87 


1.0639 


16.57 


1.0704 


18.27 


1.0769 


19.97 


1.044s 


11.52 


1 .0510 


13.21 


! 1.0575 


14.90 


1 .0640 


16.60 


1.070s 


18.30 


1.0770 


20 .00 


1 .0446 


11.55 


1 .0511 


13.23 


1.0576 


14-93 


I .0641 


16.62 


1 -0706 


18.32 


1 .0771 


20.02 


I .0447 


11.57 


1 .0512 


13.26 


1 1.0S77 


14-95 


I .0642 


16.65 


1 .0707 


18.35 


1-0772 


20.05 


I .044S 


11 .60 


1.0513 


13.29 


I .0578 


14.98 


1.0643 


16-68 


I .0708 


18.37 


1-0773 


20.07 


1 .0449 


11.62 


I. 0514 


13-31 


I. 0579 


IS. 00 


1.0644 


16.70 


1.0709 


18.40 


1.0774 


20. 10 


1 .0450 


II .65 


1.0515 


13-34 


1 .0580 


15.03 


I .0645 


16.73 


1 .0710 


18.43 


1.0775 


20. 12 


1 .0451 


11.68 


I .0516 


13-36 


I. 0581 


15.06 


I .0646 


16.7s 


1 .071 1 


18-45 


I .0776 


20. 15 


I .0452 


II . 70 


1.0517 


13-39 


1 .0582 


15.08 


1.0647 


16.78 


1 .0712 


18. 48 


I -0777 


20.18 


I .0453 


11-73 


I .0518 


13-42 


1.0583 


15.11 


1 .0648 


16.80 


1.0713 


18.50 


1.077S 


20.20 


1.0454 


11-75 


1 -0519 


13-44 


1 I -05S4 


IS. 14 


1 .0649 


16.83 


1 .0714 


18.53 


1 -0779 


20. 23 



ALCOHOLIC BEVERAGES. 



567 



EXTRACT IN WINIE— (Continued). 



Specific Ex- 


Specific 


Ex- 


Specific 


1 Ex- 


Specific 


Ex- 


Specific 


Ex- 


Specific 


Ex- 


Gravity, tract. 


Gravity 


tract. 


Gravity. 


1 tract. 


Gravity 


tract. 


Gravity 


tract. 


Gravity 


tract. 


I .0780 


20. 26 


1.0845 


21 .q6 


1 .0910 


23,67 


1.0975 


25.38 


1 I . 1040 


27.09 


1 .1105 


28.81 


I. 0781 


20.28 


1.0846 


21.99 


1 .0911 


23.70 


I .0976 


25.41 


I . 1041 


27.12 


1 . 1 106 


28.83 


I .0782 


20.31 


1.0847 


22.02 


1 .0912 


23.72 


1.0977 


25-43 


1 1.1042 


27. IS 


1 . 1107 


28.86 


1.0783 


20.34 


1.0848 


22.04 


I .0913 


23.75 


I .0978 


25.46 


1.1043 


27.17 


1 . 1 108 


28.88 


1.0784 


20.36 


1 .0849 


22.07 


1.0914 


23.77 


1.0979 


25.49 


1 . 1044 


27. 20 


1 . 1109 


28.91 


1.078s 


20.39 


1 .0850 


22.09 


1.0915 


23.80 


1 .0980 


25.51 


1.104s 


27.22 


I . 1110 


28.94 


1.0786 


20.41 


1.0851 


22.12 


I .0916 


23.83 


I .0981 


25-54 


I . 1046 


27-2S 


1 . 1111 


28.96 


I .0787 


20.44 


I .0852 


22.15 


1.0917 


23.85 


1 .0982 


25-56 


1 I. 1047 


27.27 


1 . 1112 


28.99 


I .0788 


20.47 


I .0853 i 22.17 


1 .0918 


23.88 


1 .09S3 


25-59 


1 .1048 


27 . 30 


I .1113 


29.02 


1.0789 


20.49 


1.0854 


22. 20 


I .0919 


23.91 


1 .0984 


25.62 


j 1.1049 


27.33 


1.1114 


29.04 


I .0790 


20.52 


1.0855 


22.22 


1 .0920 


23.93 


1 .0985 


25.64 


1.1050 


27.35 


I .1115 


29.07 


1.0791 


20. SS 


1.0856 


22.25 


1 .0921 


23.96 


1 .0986 


25.67 


1.1051 


27.38 


1 . 1 116 


29.09 


1.0792 


20.57 


1.0857 


22.28 


1 .0922 


23 -99 


I .0987 


25.70 


I .1052 


27.41 


1.1117 


29. 12 


I .0793 


20.60 


1.0858 


22.30 


1.0923 


24.01 


1 .0988 


25.72 


1.IOS3 


27.43 


1.1118 


29-15 


1.0794 


20.62 


1 I. 0859 


22.33 


1.0924 


24.04 


I .09S9 


25.75 


1.1054 


27.46 


1 . 1119 


29.17 


1.079s 


20.65 


1.0860 


22.36 


1.092s 


24.07 


1 .0990 


25.78 


1.1055 


27.49 


1.1120 


29, 20 


I .0796 


20.68 


1 I. 0861 


22.38 


I .0926 


24.09 


1 .0991 


25.80 


1 .1056 


27.51 


1.1121 


29- 23 


1.0797 


20. 70 


1 .0862 


22.41 


I .0927 


24.12 


I .0992 


25.83 


I-10S7 


27-54 


1 . 1 1 22 


29-25 


1.079S 


20.73 


I 1.0863 


22.43 


1 .0928 


24.14 


1-0993 


25.8s 


1 .1058 


27.57 


I - 1123 


29.28 


I .0799 


20.75 


1.0864 


22.46 


I .0929 


24.17 


1.0994 


25.88 


1.1059 


27.59 


1 . 1124 


29.31 


1.0800 


20.78 


1.086s 


22.49 


1 .0930 


24. 20 


1.099s 


25.91 


1.1060 


27.62 


I .1125 


29-33 


I .0801 


20.81 


1.0866 


22.51 


1.0931 


24.22 


1 .0996 


25-93 


1 . 1061 


27.65 


I . 11 26 


29.36 


I .0S02 


20.83 


1.0867 


22.54 


1.0932 


24.25 


I .0997 


25.96 


I .1062 


27.67 


1 . 1127 


29-39 


1 .080.5 


20.86 


1.0868 


22.57 


l.°933 


24.27 


I .0998 


25-99 


1 . 1063 


27.70 


1. 1 1 28 


29.41 


I .0804 


20.89 


1.0869 


22.59 


1.0934 


24.30 


1.0999 


26.01 


1.1064 


27.72 


I .1129 


29-44 


I .080s 


20.91 


1.0870 


22.62 


1.0935 


24.33 


1 . 1000 


26.04 


I; 106s 


27.7s 


I . 1130 


29-47 


1.0806 


20.94 


I .0871 


22.65 


1 .0936 


24.3s 


I.IOOI 


26.06 


1.1066 


27.78 


I. 1131 


29.49 


I .0807 


20.96 


1 .0872 


22.67 


1.0937 


24.38 


I . 1002 


26-09 


I . 1067 


27.80 


I . 1132 


29.52 


1.0808 


20.99 


1.0873 


22. 70 


I .0938 


24.41 


1.1003 


26-12 


I. 1 068 


27-83 


1-1133 


29-54 


I .0B09 


21.02 


1.0874 


22.72 


1.0939 


24.43 


1 .1004 


26.14 


1.1069 


27.86 


1. 1 1 34 


29.57 


1 .0810 


21 .04 


1.087s 


22.75 


I . 0940 


24.46 


I .1005 


26.17 


I . 1070 


27-88 


I.1I3S 


29.60 


I .0811 


21 .07 


1.0876 


22.78 


1.0941 


24.49 


I . 1006 


■26. 20 


1.1071 


27.96 


I .1136 


29.62 


I. 0812 


21 . 10 


1.0877 


22.80 


I .0942 


24. SI 


1 . 1007 


26. 22 


I .1072 


27.93 


I .1137 


29-65 


J. 0813 


21.12 


1.0878 


22.83 


I .0943 


24-54 


1 . 1008 


26. 25 


1.1073 


27.96 


I.1138 


29.68 


I .0814 


21. IS 


1 .0879 


22.86 


1.0944 


24.57 


1 .1009 


26. 27 


1.1074 


27.99 


1.1139 


29-70 


l.oSis 


21.17 


1 .0880 


22.88 


1.094s 


2459 


l.IOIO 


26.30 


1-107S 


28.01 


I. 1140 


29-73 


I. 0816 


21 . 20 


1 I. 0881 


22.91 


I .0946 


24.62 


1.1011 


26-33 


I .1076 


28. 04 


I. 1 141 


29-76 


I .0817 


21 .23 


I .0882 


22.93 


1.0947 


24.64 


1 . 1012 


26.35 


1 ■ lo77_ 


28-07 


I . 1142 


29-7S 


1. 0818 


21.25 


1.0883 


22.96 


1 .0948 


24-67 


1.1013 


26.38 


1 . 107S 


28.09 


1.1143 


29.81 


1. 0819 


21.28 


1.0884 


22.99 


1.0949 


24.70 


1 . IOI4 


26.41 


I. 1079 


28.12 


I. I 1 44 


29.83 


1 .0820 


21.31 , 


1.088s 


23.01 


I. 0950 


24.72 


I. 1015 


26.43 


1.1080 


28.1s 


I. 1145 


29.86 


I .0821 


21-33 1 


1.0886 


23.04 


1.0951 


24.7s 


1 .1016 


26.4$, 


I .1081 


28.17 


1 . 1 146 


29.89 


I .0822 


21 .36 


1.0887 


23.07 


1.0952 


24-78 


I . 1017 


26.49 


1 .10S2 


28.20 


1.1147 


29.91 


1.0S23 


21. 38 


1.0888 


23.09 


I.0953 


24. So 


I .loiS 


26.51 


1.1083 


28.22 


1.114S 


29-94 


1 .0824 


21.41 


1.0889 


23.12 


I.0954 


24.83 


1 . 1019 


26.54 


I . 1084 


28.25 


1.1149 


29.96 


I .0825 


21.44 


I .0890 


23.14 


1.09SS 


24.85 


I . 1020 


26.56 


1.108s 


28.28 


I . 1150 


29.99 


1.0826 


21.46 


1.0891 


23.17 


1.0956 


24.88 


1 . 1021 


26.59 


1.10S6 


28.30 


1.1151 


30.02 


1.0827 


21.49 


1 .0892 


23. 20 


1.0957 


24-91 


I . 1022 


26.62 


1.1087 


28-33 


I . 1152 


30.04 


1.0828 


21.52 


1 .0S93 


23.22 


I .0958 


24-9.1 


I .1023 


26.64 


1 .1088 


28. 36 


I.I153 


30.07 


I .0829 


21.54 


I .0894 


23.2s 


I. 0959 


24.96 


I - 1024 


26.67 


1 .1089 


28.38 


1.IIS4 


30. 10 


I .0830 


21. S7 


1.0895 


23.28 


I .0960 


24.99 


I . 1025 


26.70 


I . 1090 


28.41 


I-II55 


30.13 


1. 0831 


21-59 


I .0896 


23.30 


I .0961 


25.01 


I . 1026 


26.72 


I . 1091 


28. 43 


I .1156 


30.15 


1.0832 


21 .62 


1.0897 


23.33 


I .0962 


25.04 


1 . 1027 


26.7s 


1 . 1092 


28.46 


I-IIS7 


30. iS 


1.0833 


21.65 


1 .0898 


23.35 


1 .0963 


25.07 


I . 1028 


26.78 


1 . 1003 


28.49 


1.1158 


30. 21 


1.0S34 1 


21 .67 


1 .0899 


23.38 


I .0964 


25.09 


I . 1029 


26. So 


1. 1 094 


28.51 


I -1159 


30.23 


1.0835 


21 . 70 


I .0900 


23.41 


1.0965 


25.12 


I .1030 


26.83 


1-1095 


28.54 






1.0836 


21.73 


1 .0901 


23.43 


I .0966 


25.14 


1 . 1031 


26.85 


I .1096 


28.57 






1.0837 


21.75 


1 .0902 


23.46 


1 .0967 


25.17 


1 . 1032 


26.88 


1-1097 


28.59 






1.0838 


21.78 


1 .0903 


23.40 


I .0968 


25 .20 


1 -1033 


26.91 


I . 1098 


28.62 






1.0839 


21 .80 


1 .0904 


23SI 


I .0969 


25.22 


I. 1034 


26.93 


1 . 1099 


28.65 






1 .0840 


21.83 


1.090s 


23.54 


1 .0970 


25.25 


I. 103s 


26.96 


1 .1100 


28.67 






1 .0841 ) 


21.86 


1 .0906 


23.57 


1.0971 


25.28 


1.1036 


26.99 


1 .1101 


28.70 






1.0842 


21.88 


1 .0907 


23.59 


1.0972 


25.30 


1.1037 


27 .01 


I . 1102 


28.73 






1.0843 


21 .91 ; 


1 .0908 


23.62 


1.0673 


25.33 


1 .1038 


27.04 


1 . 1103 


28.75 






1.0844 


21.94 


1 .0909 


23.6s 


1.0974 


25.36 

1 


1.1039 


27.07 


1 . 1104 


28.78 







SOS 



FOOD INSPECTION AND ANALYSIS. 



as an indicator. Each cubic centimeter of tenth-normal alkali is equiv- 
alent to 0.006 gram acetic acid. 




Fig. 114. — Apparatus for Determining Volatile Acids in Wine. 

Non-volatile Acids. — These may be determined by difference, cal- 
culating the volatile acids for purposes of subtraction in terms of tar- 
taric or other acid in which the total acidity is expressed. Non-volatile 
acid may be directly determined by evaporating to dryness a measured 
portion of the liquor, boiling the residue with water, and titrating the 
solution with the standard alkali. 

Detection of Free Tartaric Acid. — Nessler's Method. — Some pow- 
dered cream of tartar is added to a portion of the wine in a corked flask, 
which is shaken from time to time, and the liquid finally filtered. To 
the filtrate is added a little 20% potassium acetate solution. If free 
tartaric acid is present, on stirring and especially after standing for some 
time, there will be a precipitate of cream of tartar. 

Determination of Tartaric Acid, Total, Free, and Combined. — Pro- 
visional methods A. O. A. C* 

Total Tartaric Acid. — To 100 cc. of wine add 2 cc. of glacial acetic 
acid, 3 drops of a 20% solution of potassium acetate, and 15 grams of 
powdered potassium chloride, and stir to hasten solution. Add 15 cc. 
of 95% alcohol (specific gravity 0.81) and rub the side of the beaker 
vigorously with a glass rod for about one minute to start crystallization. 
* U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 87. 



ALCOHOLIC BEyERAGES. 569 

Let Stand at least fifteen hours at room temperature; decant the liquid 
from the separated acid potassium tartrate as rapidly as possible (using 
vacuum) through a Gooch crucible prepared with a very thin film of 
asbestos, transferring no more of the precipitate to the crucible than 
necessary. Wash the precipitate and filter three times with a small 
amount of a mixture of 15 grams potassium chloride, 20 cc. of 95% alco- 
hol (specific gravity 0.81), and 100 cc. water, using not more than 20 cc. 
of the wash solution in all. Transfer the asbestos film and precipitate 
to the beaker in which the precipitation took place, wash out the Gooch 
crucible with hot water, add about 50 cc. of hot water, heat to boihng, 
and titrate the hot solution with decinormal sodium hydroxide, using 
delicate litmus tincture or htmus paper as indicator. Increase the 
number of cubic centimeters of decinormal alkali employed by 1.5 on 
account of the solubility of the precipitate. This figure multiplied by 
0.015 gives the amount of total tartaric acid in grams per 100 cc. 

Cream oj Tartar. — Ignite the residue obtained from the evaporation 
of 50 cc. of wine as directed under the determination of ash. Exhaust 
the ash with hot water, add to the filtrate 25 cc. of decinormal hydro- 
chloric acid, heat to incipient boiling, and titrate with decinormal alkali 
solution, using litmus as indicator. Deduct from 25 cc. the number 
of cubic centimeters of decinormal alkah employed, and multiply the 
remainder by 0.0188 for potassium bitartrate expressed in grams. 

Free Tartaric Acid. — Add 25 cc. of decinormal hydrochloric acid to, 
the ash of 50 cc. of wine, heat to incipient boiling, and titrate with deci- 
normal sodium hydroxide, using litmus as indicator. Deduct the number 
of cubic centimeters of alkali employed from 25, and multiply the 
remainder by 0.0075 to obtain the amount of tartaric acid necessary 
to combine with all the ash (considering it to consist entirely of potash). 
Deduct the figure so obtained from the total tartaric acid for the free 
tartaric acid. 

Determination of Free and Combined Malic Acid in Cider and Wine. 
— Evaporate 100 cc. of the sample on the water-bath to half its volume, 
cool, and treat first with 10 cc. of 10% calcium chloride solution, and 
then with ammonia to strong alkaline reaction. Let stand for an hour 
and filter. This removes the tartaric acid. Concentrate the filtrate 
by evaporation on the water-bath to 25 cc, add 75 cc. of 95% alcohol, 
heat to the boiling-point, and fiUer. Wash the residue with a mixture of 
3 parts 95% alcohol and i part water, dry, and burn to an ash. Add 
25 cc. of tenth-normal hydrochloric acid to the ash, dilute with water, 



570 FOOD INSPECTION AND ANALYSIS. 

heat to boiling, and titrate with tenth-normal sodium hydroxide, using 
phenolphthalein as an indicator. Multiply the difference between 25 
and the number of cubic centimeters required to neutralize by 0.0067 
for the grams of malic acid. 

Polarization. — Results are usually expressed in terms of the undiluted 
product. The simplest method consists in treating a measured amount 
of wine or cider with one-tenth of its volume of lead subacetate, filtering, 
and polarizing the filtrate in the 200-mm. tube. The reading is increased 
by 10% for the true direct polarization. If the filtrate is deeply colored 
after clarification with subacetate, as in the case of some artificially colored 
wines, use a loo-mm. tube and multiply by 2 the reading, increased by 10%. 

If the reducing sugars are also to be determined, one can use the same 
solution for both the polarization and the reducing sugars, as follows: 

Exactly neutralize with sodium hydroxide solution a measured quan- 
tity of the wine, using litmus paper as an indicator, and evaporate on the 
water-bath to about one-fourth its original volume. Wash with water, 
into the measuring-glass, add enough subacetate of lead solution to 
clarify, and make up with water to the original volume. Filter, and to 
a measured amount of the filtrate add 10% of its volume of a saturated 
solution of sodium sulphate. Again filter and submit to polarization a 
portion of the filtrate, making the 10% correction on the reading. 

If the invert reading is desired, subject a portion of the filtrate to 
inversion as described under Sugars. 

Determination of Reducing Sugar. — Determine the reducing sugar as 
dextrose by the Defren or the Allihn method. For this purpose dilute a 
portion of the wine, dealcoholized and clarified as described in the pre- 
ceding section, so that it contains about one-half of 1% of sugar for the 
Defren and about 1% of sugar for the Alhhn method. One may assume 
2% as the sugar-free extract of wine, the number of volumes of water to 
be added to the filtrate being determined by the difference between 2 
and the total extract as determined. 

Determination of Glycerin. — Evaporate 100 cc. of the wine on the 
water-bath to a volume of about 10 cc, after which i or 2 grams of fine 
sand are added and sufficient milk of lime to render alkaline. Continue 
the evaporation nearly to dryness, and after cooling shake with 50 cc. of 
95% alcohol, heat to boiling on the water-bath, and filter. Wash the 
insoluble residue on the filter-paper with several portions of hot alcohol, 
using say 100 cc, adding the washings to the original filtrate. Evaporate 
the alcoholic filtrate to a syrupy consistency on the water-bath, dissolve 



ylLCOHOLlC BEVERAGES. 571 

the residue in 10 cc. of absolute alcohol, and transfer to a flask with 15 cc. 
of ether. Tightly cork the flask, shake, and allow to stand for some time. 
Then filter into a tared dish, wash with a mixture of absolute alcohol (i 
part) and ether (1.5 parts), evaporate the filtrate to syrupy consistency on 
the water-bath, drj' in a water-oven for one hour, and weigh as glycerin. 

With plastered wines the results are too high, for the reason that the 
potassium sulphate present is decomposed by the lime to form potassium 
hydroxide, soluble in glycerin and alcohol. In such wines the above 
residue should be ignited, and the ash deducted from the first weight. 

Determination of Potassium Sulphate. — x\cidify 100 cc. of the sample 
with hydrochloric acid, heat to boiling, and add an excess of barium 
chloride solution. Filter, wash, dr)', ignite, and weigh as barium sul- 
phate, calculating the equivalent of potassium sulphate. The presence 
of the latter in excess of 0.06 gram per 100 cc. indicates plastering. 

Determination of Tannin. — An approximate method of determining 
tannin is that of Nessler and Barth. 12 cc. of wine are treated with 30 
cc. of alcohol and filtered. 35 cc. of the filtrate, which corresponds to 
10 cc. of the wine, is evaporated to about 6 cc. and transferred to a lo-cc. 
graduated centrifuge tube. h. few drops of 40% sodium acetate are 
then added, and a slight excess of 10% ferric chloride. The tube is 
corked, gently agitated, and allowed to stand for twenty-four hours. The 
volume of the precipitate is then measured, each cubic centimeter being 
equivalent to 0.033% of tannin in the wine. 

Foreign Coloring Matters in Wine. — A wide variety of artificial colors 
have been found in red wine. Those most commonly employed at present 
are cochineal, fuchsin, and acid fuchsin. 

The Pharmacopceia prescribes the following color tests; 

If 2 cc. of red wine be mixed in a test-tube with 2 drops of chloroform 
and 4 cc. of normal potassium hydroxide, and the mixture carefully 
heated, the disagreeable odor of isonitril should not become preceptible 
(absence of various anilin colors). 

If 50 cc. of red wine be treated with a slight excess of ammonia water, 
the liquid should acquire a green or brownish-green color; if it be then 
well shaken with 25 cc. of ether, the greater portion of the ethereal layer 
removed and evaporated in a porcelain capsule with an excess of acetic 
acid and a few fibers of uncolored silk, the latter should not acquire a 
crimson or violet color (absence of fuchsin). 

If 25 cc. of red wine heated to about 45° C. be well agitated with 25 
grams of manganese dioxide, the liquid filtered off and acidulated with 



57* FOOD INSPECTION AND ANALYSIS. 

hydrochloric acid, it should not acquire a red color (absence of sulpho- 
fuchsin). 

Dupre's Method of Detection.* — Small cubes of jelly measuring about 
2 cm. in thickness are prepared as follows: Dissolve i part of pure 
gelatin in lo parts boiling water and pour upon a plate to harden. This 
is then cut into cubes of the above size by a sharp knife. When a wine 
is suspected of containing foreign color, one of the cubes is immersed 
therein and allowed to remain for twenty-four hours, after which it is 
removed, washed slightly in cold water, and cut through with a knife. If 
the color is a natural one, it will lightly tinge the outer surface of the 
cube, but will not permeate far below the surface, so that the inner por- 
tion of the cross-section will be largely free from color. Nearly all foreign 
coloring matters used in wine, such as most coal-tar dyes, cochineal, 
Brazil wood, logwood, etc., will be found to deeply permeate the jelly 
cube often to the center. Information as to the nature of the color may 
sometimes be gained by immersing the dyed jelly cube in weak ammonia. 
If the color be rosanilin, the cube is decolorized, if cochineal, a purple 
coloration will result, and if logwood, a brown tinge. 

Cazeneuve's Methods for Detecting Colors in Wine. — While by no 
means complete, the following method of Cazeneuve as condensed and 
arranged by Gautier (La Sophistication des Vins) will often be found 
helpful. If other colors than these are evidently present, tests should 
be made as indicated in Chapter XVI. Cazeneuve employs the fol- 
lowing reagents: 

(i) Yellow oxide of mercury, finely pulverized. 

(2) Lead hydrate, freshly precipitated, well washed, suspended in 
about twice its volume of water; to be kept in a stoppered bottle; should 
be renewed after several days' use. 

(3) Gelatinous ferric hydrate, well washed from ammonia, suspended 
in about twice its volume of water. 

(4) Manganese dioxide, pulverized. 

(5) Concentrated, chemically pure sulphuric acid. 

(6) White wool. 

(7) Stannous hydrate, freshly precipitated, well washed, suspended in 
water, and kept from exposure to light and air. 

(8) Collodion silk, the artificial silk produced from nitro-cellulose. 
This fiber has a special affinity for basic dyes. 

* Jour. Chem. Soc, 37, p. 572, 



ALCOHOLIC BEVER/IGES. 



573 



To lo cc. of the wine are added 0.2 gram finely powdered yellow oxide of mercury. 
Boil and pour upon a double filter. 



Filtrate colored either before or after acidifying. 






0,3 









o 
5* 



Filtrate colored yellow. 10 cc. 
of the wine are warmed with 2 
grams lead hydrate. Filter. 



Filti'ate colored yellow. 
A large excess of lead 
hydrate is added and 
the liquid is boiled. 



S i» 



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Filtrate colored red. 10 
cc. of the wine are treated 
with 2 grams lead hydrate 
and filtered. 

H Filtrate colorless. 



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574 FOOD INSPECTION AND /IN A LYSIS. 



MALT LIQUORS. BEER. 

In its wadest sense beer may be defined as the product of fermentation 
of an infusion of almost any farinaceous grain with various bitter extract- 
ives, but unless otherwise qualified it should be strictly apphed to the 
beverage resulting from the fermentation of malted barley and hops. 
In the manufacture of beer two distinct processes are employed, viz., 
malting or sprouting the grain, and brewing. Many brewers do noth- 
ing but the latter, buying their malt already prepared. 

Malting. — For the preparation of malt, the barley is steeped in water 
for several days, after which the water is drained off and the moist grain 
is "couched," or piled in heaps, on a cement floor, where it undergoes a 
spontaneous heating process, during which it germinates, forming the 
ferment diastase. When the maximum amount of diastase has been 
produced, indicated by the length of growth of the sprout, or "acrospire" 
within the grain, the germination is checked by spreading the grain in 
layers over a perforated iron floor, and finally subjecting it to artificial 
heat. The character of the malt and of the beer produced from it depends 
largely on the heat at which the "green" malt is kiln dried. If dried 
between 32° and 37° C. it forms pale malt, which produces the lightest 
grades of beer. Most beer is made from malt dried at higher tem- 
peratures, say from 38° to 50°, the depth of color of the liquor varying 
with the heat to which the malt has been subjected, while the color of the 
malt varies from the "pale" through the "amber" to "brown," or even 
black. The darkest grades are sometimes dried at temperatures over 
100° C, even to the point where the starch becomes caramehzed. 

A more modem method consists in the so-called pneumatic malting, 
wherein the whole operation is conducted in a large rotating drum, which 
holds the grain, and in which the temperature and moisture at different 
stages is carefully controlled by the admission to the interior of the drum 
of moisture-laden or dry air, heated to the required degree. 

The chief object of malting is the production of diastase, which by 
its subsequent action on the starch converts it into the fermentable sugars 
maltose and dextrin. Malt contains much more diastase than is necessary 
to convert the starch simply contained therein to maltose, and is capable 
of acting on the starch of a considerable quantity of raw grain, such 
as com or rice, when mixed with it. This practice of using other grains 
than malt is prohibited in some localities, such as Bavaria. 



ALCOHOLIC BEVERAGES. 575 

Brewing. — The malt, or mixture of malt and raw grain, is first crushed 
and "mashed" b)- stirring with water in tubs at 50° to 60° C, finally 
heating to 70°. During this process the conversion of the starch to mal- 
tose and dextrin takes place. The resulting liquor is known as "wort," 
containing, besides maltose and dextrin, peptones and amides. The 
clear wort is then drawn off from the residue, and boiled to concentrate 
the product and to sterilize it, after which hops (the female flower of 
the Humulus lupulus) are added and the boiling continued. Hops 
contain resins, bitter principles, tannic acid, and a peculiar essential oil, 
all of which are to some extent imparted to the wort. After cooling and 
settling, the clear wort is run into fermenting-vats, where selected yeast, 
usually saccharomyces cerevisice, is added, and the alcoholic fermentation 
allowed to proceed. The temperature greatly affects the character of 
the fermentation. If kept between 5° and 8° C, a slow fermentation 
proceeds, knowTi as bottom fermentation, during which the yeast settles 
out at the bottom. This is much more easily controlled than the 
quick or top fermentation, which takes place at from 15° to 18°, much 
of the yeast in the latter case being carried to the surface, from which it 
is finally removed by skimming. In either case the yeast feeds upon 
the albuminous matter present. x\t the proper stage the beer is drawn off 
from the larger portion of the yeast, and run into casks, or tuns, in which 
an after-fermentation proceeds. The beer is finally clarified by treatment 
with gelatin or beech shavings or chips, to which the floating yeast-cells 
and other impurities attach themselves. It is finally stored in barrels 
coated with brewers' pitch, or pasteurized at 60° C. and bottled. 

Varieties of Beer. — Formerly the division of beers into "lager," 
"schenk," and "bock" was made by reason of the fact that beer had to 
be brewed imder certain climatic conditions and at certain seasons only. 
Now, with improved means for artificial refrigeration, and with better 
methods controlling all stages of the process, these distinctions arc less 
marked. 

Lager Beer (from lager, a storehouse) is a term originally applied to 
Bavarian beer, but is now given to any beer that has been stored several 
months. Formerly lager beer was made early in the winter, and stored 
in cool cellars till the following spring or summer, during nearly all of 
which lime a slow after-fermentation took place. The best lager beers 
contain a low proportion of hops, and are high in extract and 
alcohol. 

Schenk Beer is a quickly fermented beer made in winter for immedi- 



576 



FOOD INSPECTION AND ANALYSIS. 



ate use. It is brewed in from four to six weeks and will not keep long 
without souring. 

Bock Beer, according to older systems of nomenclature, occupied a 
middle place between lager and schenk, being an extra strong beer brewed 
for spring use and made in limited quantities, not being intended for 
storage. 

Berlin Weiss Bier is prepared by the quick or top fermentation of a 
wort consisting of a mixture of malted barley and wheat with hops. It is 
high in carbon dioxide, being usually bottled before the second fermen- 
tation has ended. 

Ale is virtually the English name for beer. It is usually lighter colored 
than lager beer, being made from pale malt by quick or top fermentation, 
and containing rather more hops than beer. It has a high content of 
sugar, due to checking fermentation at an earlier stage than in ordinary 
beer. 

Porter is a dark ale, the deep color of which should be due to the use 
of brown malt dried at a high temperature, but which is sometimes colored 
by the admixture of caramel. It has a large extract, chiefly sugar. 

Stout is an extra-stroog porter, being high both in alcohol and extract. 

Composition of Beer. — Beer is a somewhat complex liquor. Besides 
water, alcohol, and sugar, it contains carbon dio.xide, succinic acid, dex- 
trin, glycerin, tannic acid, the resinous bitter principles of hops, nitrog- 
enous bodies (chiefly peptones and amides), alkaline and lime salts 
(chiefly phosphates), fat (traces), acetic acid and lactic acid. The latter 
acid constitutes the chief fixed acid of beer. 

The following analyses of different varieties of beer are due to Konig: 



Variety. 




■£ > 

0.0 

U3 






If 


.a . 

a* 


1 

W 


tn w 

l| 


II 


■2 = 




c 
■c 

5 




T 

1^ 


Schenk 

Lager 

Export beer. 

Bock 

Weiss bier.. 

Porter 

Ale 


20S 

109 

84 

40 
.^8 


I.OII4 
I. 0162 
I. 0176 
I. 0213 
I. 0137 
I.OI9I 
I.OI4I 


91. II 

90.08 
89.01 
87.87 
91.63 
88.49 
89.42 


0.197 

0.196 

0.209 

0-234 
0.297 

0.215 

0.2CI 


3-36 

3-93 
4-40 
4.69 

2-73 
4-7° 
4-75 


5-34 
5.70 
6.38 
7.21 
5-34 
6-S9 
5-65 


0.74 
0.71 
0.74 

0-73 
0.58 
0.65 
0.61 


0-95 
0.88 
1.20 
1. 81 
1.62 
2.62 
1.07 


3-ix 
3-73 
3-47 
3-97 
2.42 
3.08 
1. 81 


0.156 

0.151 
0.161 
0.165 
0.392 
0.281 
0.278 


0.12 

0.165 
0.154 
0.176 
0.092 


0.204 
0.228 
0.247 
0.263 
0.149 

0-363 
0.31 


0-055 
0.077 
0.074 
0.089 
0.034 
0-093 
0.086 



Fifteen samples of lager beer and seven samples of pale ale, bouT;ht 
in Massachusetts bar-rooms, representing as nearly as possible the quality 



ALCOHOLIC BEVERAGES. 



57/ 



of liquor sold every day to patrons by the bottle or glass, were analyzed 
by the Board of Health with the following results: 





Per Cent of 

Original Wort 

Extract. 


Per Cent of 

Alcohol by 

Weight. 


Per Cent of 
Extract. 


Beer — - Maximuni 


iS.gi 

7-33 
15.04 
15.99 
10.95 
13-56 


7.07 
1. 10 
4-45 
5-37 
3-53 
4.49 


1 :6 


Minimum. 


3-67 
S-92 
5-47 
3-38 
4-54 


Mean 




Minimum 


Mean 



Five out of the 15 beer samples and 3 out of the 7 ale samples con- 
tained salicylic acid. 

The percentage composition of the ash of German beer is thus given 
by Konig as the mean of 19 analyses: 



Ash in 

xoo Parts 

Beer. 


Potash. 


Soda. 


Lime. 


Magnesia. 


Iron 
O.xide. 


Phos- 
phoric 
Acid. 


Sul- 
phuric 
Acid. 


SiUca. 


Chlorine^ 


0.306 


3^.67 


8.94 


2.78 


6.24 


0.48 


31-35 3-47 


9.29 


2-93 



Malt and Hop Substitutes. — By reason of the fluctuation in market 
price of these two chief constituents of beer, it sometimes becomes a 
question of economy to employ cheaper substitutes wholly or in part 
for one or the other. There are two classes of malt substitutes, (i) those 
which, like corn, rice, and wheat, are mixed directly with the malt before 
"mashing," and, like the malt, have to undergo a saccharous fermenta- 
tion before being acted on by yeast, and (2) such substances as cane 
sugar, invert sugar, commercial glucose, and dextrin, which are added 
to the wort at a later stage in the brewing, just before the addition of the 
yeast, being in condition to be readily acted on by the latter. 

Glucose is by far the most common malt substitute, by reason of the 
fact that its sugars much resemble those of malt, and are in readily ferment- 
able form. Diastase forms from the malt dextrin and maltose, while 
commercial glucose contains dextrin, maltose, and dextrose. 

When the price of malt is abnormally high, the addition of glucose 
is decidedly economical, but when ordinary conditions prevail, the cost 
of the two, figured ^\^th reference to their yield in alcohol and extract, 
is about the same. Aside from the question of economy, however, there 
are advantages in the use of glucose, such as diminishing the nitrogenous 
content of the wort without lessening the alcohol or extract yielded. 



578 FOOD INSPECTION /IND ^N^ LYSIS. 

The nitrogenous matter left after fermentation is one of the chief 
causes of cloudiness or turbidity in the finished product, and is some- 
times difficult to remove. By the use of glucose, especially in brewing 
clear bottled ales and sparkling pale beers, the appearance of the 
product is much enhanced. The temptation at times to add more 
glucose than is necessary to accomplish this is great. A high-grade malt 
may have as much as 40% of glucose added to its wort and still produce 
an acceptable beer. With a low-grade malt, glucose yields a very poor 
quality of beer. Hence the use of glucose may or may not be desirable, 
though it can hardly be considered unqualifiedly as an adulterant. 

As to the employment of hop substitutes, the question of relative 
price again enters in. Only when the price of hops is high is there any 
special inducement to use substitutes. Quassia wood, chiretta, gentian, 
and calumba, all of which yield bitter principles, have been used in beer, 
and cannot be considered detrimental to health. Allen and Chattaway 
have found the first two in beer examined by them.* Such poisonous 
substances as cocculus indicus, picric acid, and strychnine are alleged to 
have been used as hop substitutes, but there is no authentic record of any 
of them having been found in recent years, if at all. 

Adulteration of Beer and Standards of Purity. — The Committee on 
Standards of the A. O. A. C. in their proposed definitions and standards 
have distinguished between malt beer, which should be a malt liquor 
obtained by fermenting an infusion of malted barley, and adding thereto 
nothing but yeast and hops, and beer, or lager beer, which may contain 
non-injurious malt and hop substitutes in addition to malt. Their pro- 
posed standard for malt beer is as follows : 

Alcohol should be not less than 4% by volume; the extract should 
at least equal the per cent of alcohol, and should contain not less than 
1% of nitrogen; the ash should not exceed 0.4%, and the phosphoric acid 
should be not less than 0.05%. 

Non-injurious bitter principles are no doubt employed in place of 
hops, and unless the liquor is sold for a pure malt beer, they cannot be 
regarded as adulterants. 

The tendency to shorten the time of storage of beer, or to sell it without 
storing at all, lessens or does away with the after-fermentation, resulting 
in a lack of "life" or effervescence in the product. This is sometimes 
made up by the addition of sodium bicarbonate. 

Distinction between Malted and Non-malted Liquors. — In some 
states where strict prohibitory hquor laws are in force, it is illegal to sell 

* Analyst, 12, 112. 



ALCOHOLIC BEVER/tGES. 



579 



"malt liquors," so that when convictions are obtained, it is necessary 
for the analyst to distinguish between liquors brewed wholly or in part 
from malt and those in which no malt has been used, but which were 
brewed entirely from malt substitutes. This distinction is not always 
easy to make with precision. In the absence of malt, glucose is usually 
the sole source of alcohol in these beverages. Parsons * has shown that 
the most striking points of difference between malted and non-malted 
liquors are in their per cent of phosphoric acid and albuminoids, and that 
pure malt beer or ale should contain at least 0.04% P2O5, and 0.25% 
albuminoids (NX6.25). A low ash and liigh content of sulphates in 
the ash are also indicative of glucose. The following analyses made by 
Parsons clearly show these distinctions : 



COMPOSITION OF SEVENTY-SIX SAMPLES OF AMERICAN MALT LIQUORS. 




Specific 
Gravity. 


Alcohol 
by Vol- 
ume. 


Extract. 


Albumin- 
oids 
CNX6.25) 


Phos- 
phoric 
Acid. 


Ash. 


Sul- 
phates in 
Ash. 


Free 
Acid. 


Average 

Maximum 

Minimum. 


1 .0100 
1.0210 
1.0047 


5-6i 
7-85 
0-35 


4.61 
7.64 
3-iS 


0.470 
0.614 
0.290 


0.06! 
0.095 
0-045 


0.209 
0.296 
0.147 


6.34 

12.67 

2.44 


0.26 
0.87 

O.IO 



TYPICAL ANALYSES OF BEERS APPARENTLY NOT BREWED FROM MALT. 



Number. 


Specific 
Gravity. 


Alcohol 
by Vol- 
ume. 


E.xtract. 


Albumin- 
oids 
(NX6.2S) 


Phos- 
phoric 
Acid. 


Ash. 


Sul- 
phates. 


Free 
Acid. 


I 


1.0074 
1.0098 
I . 0062 
I.0112 
I. 0041 


1.68 
2.63 
2.27 
2. II 

1.8s 


2.52 
3-40 
2.25 

3-53 
1-73 


0. 114 
0.215 
0.150 

0-133 
0.031 


O.OIO 

0.023 
0.015 
0.015 

O.OIO 


0.19 

0.180 

0.124 

0.140 

0.088 


21.22 

11.30 

io.8i 
12.50 


Normal 








( C 


4 


(( 




(( 







The ash of the fifth sample is thus compared with that of the average 
beer as given by Blyth: 

Malt Beer "No-malt" Beer 

(Blyth). (Parsons). 

K2O 37.22 12.93 

NajO 8.04 19.61 

CaO 1 .93 Undetermined 

MgO S.51 

Fe^O^ Trace 

SO3 1.44 10.81 

PA 32-09 10.71 

CI 2.91 21.76 

SiO, 10.82 7.50 

* Jour. Am. Chem. See, 24, 1902, p. 11 70. 



580 FOOD INSPECTION AND ANALYSIS. 

Preservatives in Beer. — Antiseptics are frequently added to malt 
liquors, salicylic acid being most commonly used. Fluorides of ammo- 
nium and sodium have been found in American beer. Other preserva- 
tives to be looked for are benzoic acid and sulphites. Beer casks are 
frequently "sulphured" or fumed with a solution of calcium bisulphite, 
so that the beer may derive its content of sulphites from this source. 

In cases of police seizure of beer sold in bulk or in opened bottles for 
the purpose of ascertaining whether or not their alcoholic content exceeds 
certain limits iixed by law, a little formalin had best be added as soon 
possible after the seizure to prevent further fermentation. This is espe- 
cially desirable in cases where there is likely to be some delay in making 
the analysis, so as to forestall any claim on the part of the defendant of 
additional alcohol being formed after the seizure. From 6 to 8 drops of 
a 40% solution of formaldehyde to a quart of beer is sufficient, and this 
quantity will not appreciably affect the analysis. 

Arsenic in Beer. — In 1900 a very disastrous epidemic of arsenical 
poisoning occurred in Manchester, England, involving several thousand 
cases, many of wliich were fatal. The arsenic was traced to sulphuric 
acid, which entered into the manufacture of commercial glucose used 
in the beer, the acid found so highly arsenical being made from a certain 
variety of Swedish pyrites, which was found to be abnormally high in 
arsenic. There appeared to be no doubt whatever that the beer was the 
sole cause of the trouble. While the presence of arsenic was in this case 
accidental, carelessness was shown on the part of those having to do with 
the purity of the materials entering into the composition of the beer. 
Fortunately no other instances are on record of arsenical poisoning from 
malted liquors. A large number of samples of American beer have been 
examined in the laboratory of the Food and Drug Department of the 
Massachusetts State Board of HeaUh, and only insignificant traces of 
arsenic have in any case been found. 

Temperance Beers and Ales. — Many varieties of these so-called tem- 
perance drinks are home-made, as well as sold on the market. They are 
usually slightly fermented infusions of various roots and herbs, including 
ginger or sassafras, with molasses or sugar and yeast, and more often 
contain less than 1% of alcohol by volume. Among them are included 
spruce beer, and the various root beers, such as ginger beer and ginger 
ale. The latter beverages are generally carbonated. Numerous brands 
of bottled beer are manufactured, which contain virtually the same body 
and characteristic flavor as lager beer, but not the alcohol. Indeed the com- 



ALCOHOLIC BEVERAGES. 581 

position of many of these beverages is identical with that of lager beer, 
excepting in alcoholic content, being made by substantially the same 
process and out of the same ingredients, but with the alcohol finally 
removed by steaming, so that the liquor comes within the limits of a 
temperance beverage. 

Of this class is Uno beer, which ranges from 0.6 to 0.9 per cent in 
alcohol. 

Methods of Analysis. — For determinations of specific gravity, alcohol, 
extract (by direct method), and ash see pp. 527, 528, and 547. For pre- 
servatives see Chapter XVII. 

Calculation of Extract in Beer. — When extreme accuracy is desired, 
the result obtained by evaporating at 100° a weighed amount of the 
beer cannot be accepted, on account of the dehydration of the maltose at 
a temperature exceeding 75° C. Unless the evaporation is conducted 
at that temperature (a difficult operation), a closer approximation to the 
truth is obtained, especially with beer high in sugar, by calculation as 
follows. 

Evaporate a measured quantity of the beer to one-fourth its volume 
on the water-bath, make up with water to its original measure, and deter- 
mine the specific gravity of the dealcoholized beer. Then by means of 
Schults and Ostermann's table, pp. 582-6, calculate the extract corre- 
sponding. 

Original Gravity of Beer Wort and its Determination. — Following a 
long-established custom of the Englisli excise, the duty on beer has been 
based on the specific gravity of the original wort, by which is meant the 
wort of the beer before any of its sugar has been lost by fermentation. 

From the content of alcohol in the beer the sugar originally presenc 
in the wort may be calculated, assuming that the alcohol amounts to 
about half the sugar used up in fermentation. 

Obtain the specific gravity of the beer, dealcoholized and made up 
to its original volume, as in the calculation of the extract. This 
is called the "extract gravity." Note the specific gravity correspond- 
ing to the alcohol found, i.e., the specific gravity of the distillate in the 
alcohol determination, when made up to the original volume, and subtract 
this from i. The difference is known arbitrarily as the "degree of spirit 
indication." 

From the table of Graham, Hofmann, and Redwood,* p. 587, 
the "degrees of gravity lost" corresponding to the "spirit indication" 
* Report on Original Gravities, 1852; Allen's Com. Org. Anal., I., p. 136. 



58: 



FOOD INSPECTION AND /1NALYSIS. 



EXTRACT IN BEER WORT.* 
[According to Schultz and Ostermann.] 





Extract. 


Specific 


Extract. 


Specific 


Extract. 


Specific 


Extract. 


Specific 


















Gravity 


Per 


Grams 


Gravity 


Per 


Grams 


Gravity 


Per 


Grains 


Gravity 


Per 


Grams 


at 15° C. 


Cent 

by 

Weight 


per 
100 cc. 


at is°C. 


Cent 

by 

Weight 


per 
100 cc. 


at 15° C. 


Cent 

by 

Weight 


per 
100 cc. 


at 15° C. 


Cent 

by 

Weight 


per 
100 cc. 


I ,0000 


0.00 


0.00 


I .0065 


1.69 


1.70 


I .0130 


3-35 


3-39 


I 0195 


5. 06 


5. 16 


1 .0001 


0.03 


0.03 


1 .0066 


1.72 


1.73 


1.0131 


3-38 


3-42 


I .0196 


5 09 


5.19 


1 .0002 


0.05 


0.05 


I .0067 


1-74 


I. 75 


I .0132 


3-41 


3.46 


1.0197 


5.12 


5.22 


1 .0003 


0.08 


0.08 


1.0068 


1-77 


1.78 


I-OI33 


3.43 


3-48 


1 .0198 


5. IS 


5. 25 


1 .0004 


0. lO 


0. 10 


1.0069 


I ■79 


1.80 


1.0134 


3.46 


351 


1.0199 


5.17 


5 -.27 


1 .0005 


0.13 


0.13 


I .0070 


1.82 


1.83 


I-OI3S 


3.48 


3-53 


1 .0200 


5.20 


5.30 


1.0006 


0. 16 


0.16 


I .0071 


1.84 


1.85 


I .0136 


3-51 


3.56 


1 . 0201 


5.23 


5. 34 


1 .0007 


0.18 


0.18 


I .0072 


1.87 


1.88 


1.0137 


3-54 


3.59 


1 .0202 


5.25 


5.36 


1 .0008 


0. ar 


0.21 


1.0073 


1 .90 


1. 91 


I. 0138 


3.56 


3.61 


1 .0203 


5.28 


5 39 


I .0009 


0.24 


0,24 


1.0074 


1.92 


1.93 


I. 0139 


3-59 


3 64 


1 .0204 


5.30 


5.41 


I .0010 


0. 26 


0, 26 


1.007s 


I .95 


1 .96 


I .0140 


3.61 


3.66 


1 .0205 


5. 33 


5-44 


1 .001 1 


0.29 


0. 2Q 


I .0076 


1.97 


I .08 


I .0141 


3 64 


3-69 


1 .0206 


5. 35 


5. 46 


1 .0012 


0.31 


0.31 


1.0077 


2.00 


2.02 


I .0142 


3.66 


3-71 


1 .0207 


5.38 


5. 49 


1.0013 


0.34 


0.34 


I .0078 


2.02 


2.04 


I .0143 


3 69 


3-74 


1 .0208 


5.40 


SSI 


1.0014 


0.37 


0-37 


1.0079 


2.0s 


2.07 


1.0144 


3-72 


3-77 


1 .0209 


5.43 


5.54 


I .oois 


0.30 


0.30 


I .0080 


2.07 


2 .09 


1.0145 


3-74 


3-79 


I .0210 


5.45 


5- 56 


1 .0016 


0.42 


0.42 


r .0081 


2.10 


2.12 


1 . 1 46 


3-77 


3.83 


1.0211 


5. 48 


S.6q 


I ,0017 


0.45 


0.4S 


I .0082 


2.12 


2.14 


I. 0147 


3.79 


3.8s 


1 .0212 


5. SO 


5.62 


1 .0018 


0.47 


0.47 


I .0083 


2. IS 


2.17 


1 .0148 


3.82 


3.88 


I. 0213 


S.53 


5.65 


1 .0019 


0.50 


0.50 


I .0084 


2.17 


2.19 


1.0149 


3-85 


3.91 


I .0214 


5. 55 


5.67 


I .0020 


0.52 


0.52 


I .0085 


2. 20 


2. 22 


I .0150 


3.87 


3-93 


I .0215 


5. 57 


5.69 


1. 002 1 


0.55 


O-SS 


I .0086 


2.23 


2.2s 


I. 0151 


3 90 


3-96 


I .0216 


5.60 


5.72 


1.0022 


0.58 


0.58 


I .0087 


2.2s 


2.27 


1 .0152 


392 


398 


1.0217 


5.62 


5.74 


1.0023 


0.60 


0.60 


1 .0088 


2.28 


2.30 


I-01S3 


3-95 


4.01 


1 .0218 


5. 65 


5. 77 


1.0024 


0.63 


0.63 


1.0089 


2.30 


2.32 


I. 0154 


3-97 


4.03 


1 .0219 


5.67 


5.79 


1.0025 


0.66 


0.66 


T .0090 


2.33 


2.35 


I.OI5S 


4.00 


4.06 


1 .0220 


S.70 


5.83 


1 .0026 


0.68 


0.68 


I .0091 


2.35 


2-37 


1 -0156 


4.03 


4.09 


1 .0221 


5-72 


S.85 


1 .0027 


0.71 


0.71 


1 .0092 


2.38 


2.40 


I.OI57 


4.05 


4.11 


1 .0222 


5.7s 


5.88 


1 .002S 


0.73 


0.73 


I .0093 


2.41 


2-43 


1 .0158 


4.08 


4.14 


1 .0223 


5.77 


5.90 


1.0029 


0.76 


0.76 


I .0094 


2-43 


2.45 


10159 


4.10 


4-17 


1 .0224 


5. 80 


5.93 


I .0030 


0.79 


0.79 


I .0095 


2.46 


2.48 


1 .0160 


4-13 


4.20 


1.0225 


5. 82 


5. 95 


1.0031 


o.Si 


0.81 


1 .0096 


2.48 


2.50 


1 .0161 


4.16 


4-23 


I .0226 


5. 84 


5.97 


1.0032 


0.84 


0.84 


I .0097 


2. SI 


2.53 


1 .0162 


4.18 


4-25 


I .0227 


5.87 


6.00 


1.0033 


0.87 


0.87 


I .0098 


2.53 


2. 55 


I .0163 


z;.2i 


4.28 


1.0228 


5.89 


6.02 


X.0034 


0.89 


0.89 


I .0099 


2.56 


2.59 


I .0164 


4-23 


4-30 


1 .0229 


5.92 


6.06 


1.0035 


0.92 


0.92 


I .0100 


2.58 


2.61 


1.0165 


4.26 


4-33 


1 .0230 


5. 94 


6.08 


1.0036 


0.94 


0.94 


I .0101 


2.61 


2.64 


1 .0166 


4.28 


4-35 


1 .0231 


5. 97 


6. 11 


1.0037 


0.97 


0.97 


I .0102 


2.64 


2.67 


I .0167 


4-31 


4.38 


1 .0232 


5.99 


6.13 


1 .0038 


1 .00 


1 .00 


I .0103 


2.66 


2.69 


1 .0168 


4-34 


4.41 


I -0233 


6.02 


6.16 


1.0039 


1 .02 


1 .02 


I . I 04 


2.69 


2.72 


I .0169 


4-36 


4-43 


1.0234 


6.04 


6.18 


1 .0040 


1.05 


i.°S 


I .0105 


2.71 


2.74 


I .0170 


4.39 


4.46 


1.023s 


6.07 


6.21 


I .0041 


1.08 


1.08 


I .0106 


2.74 


2.77 


1.0171 


4.42 


4- SO 


1 .0236 


6.09 


6.23 


I .0042 


1 . 10 


1 .10 


I .0107 


2.76 


2.79 


1.0172 


4.44 


4-52 


1.0237 


6. II 


6.25 


1.0043 


1. 13 


1. 13 


I .0108 


2.79 


2.82 


1-OI73 


4-47 


4-55 


1 .0238 


6.14 


6. 29 


1.0044 


I. IS 


1. 16 


I .oiog 


2.S2 


2.85 


I. 0174 


4.50 


4.38 


1.0239 


6.16 


6.31 


1.0045 


1. 18 


1. 19 


I .0110 


2.84 


2.87 


1 .0175 


4.53 


4.61 


I .0240 


6. 19 


^^l 


1.0046 


1 .21 


1.22 


I .0111 


2.87 


2.90 


1 .0176 


4-55 


4.63 


1 .0241 


6.21 


6.3« 


1.0047 


1.23 


1.24 


I .0112 


2.8g 


2 92 


1.0177 


4-58 


4.66 


1 .0242 


6.24 


6.39 


1 .004S 


I . 26 


1.27 


I .0113 


2.92 


2.9s 


1 .0178 


4. 61 


4 69 


1.0243 


6.26 


6,41 


X .0049 


1.29 


1.30 


I .0114 


2.94 


2.97 


1.0179 


4.63 


4-71 


1.0244 


6. 29 


6.44 


1 .0050 


I. 31 


1.32 


I .0115 


2.97 


3- 00 


I .0180 


4.66 


4-74 


1.024s 


6.31 


6.46 


1 .0051 


1.34 


1. 35 


1 .0116 


2.99 


3.02 


i.oiSl 


4.69 


4.77 


1 .024P 


6.34 


6.50 


I .0052 


1.36 


1-37 


I .0117 


3.02 


3.06 


I .0182 


4-71 


4.80 


1.0247 


6.36 


6.52 


1.0053 


1.39 


1.40 


I .0118 


3-°5 


3.09 


1.0183 


4-74 


4.83 


1 .0248 


6.39 


6.55 


1.0054 


I. 41 


1.42 


i.oiig 


3.07 


3-II 


I .01S4 


4-77 


4.86 


1,0249 


6.41 


6.57 


1.0055 


1.44 


1.4s 


I .0120 


3.10 


3-14 


1.0185 


4-79 


4.88 


1 1.0250 


6.44 


6.60 


1.0056 


I .46 


1-47 


I .0121 


3-12 


3.16 


1 .0186 


.,.82 


4-5- 


I .0251 


6.47 


6.63 


X.0057 


1.49 


i-SO 


-I .0122 


3-15 


3-19 


I .0187 


4- 8s 


<;-94 


I .0252 


6.50 


6.66 


1.0058 


I. 51 


I. 52 


I. 0123 


3-17 


3.21 


1.0188 


4. 88 


4-97 


1.0253 


6.52 


6.58 


1.0059 


1-54 


l-SS 


I . 0124 


3.20 


3.24 


1 .0189 


4.90 


4-99 


I .0254 


6.55 


6.72 


1.0060 


1.56 


1-57 


I .0125 


3-23 


3.27 


1 .0190 


4-93 


5.02 


I.02SS 


6.58 


6.75 


X .oc6i 


1.50 


1 .60 


1 .0126 


3-2S 


329 


1 .oigi 


4.96 


5.05 


1 .0256 


6.61 


6.78 


1.0062 


1.62 


1.63 


I .0127 


3.28 


3-32 


1.0192 


4.98 


5.08 


1.0257 


6.63 


6.80 


1.0063 


1.64 


i.l.S 


I .0128 


3-30 


3-34 


1.0193 


S-oi 


5. II 


1 .0258 


6.66 


5.83 


X.0064 


X.67 


1.68 


I .0129 


3.33 


3.37 


I. 0194 


5 04 


S14 


1.0259 


6.59 


6.86 



* Calculated from, results obtained by drying below 75° C. 



ALCOHOLIC BEyERAGES. 
EXTRACT IN BEER WOWY— (Continued). 



583 





Extract. 


Specific 


Extract. 


Specific 


Extract. 


Specific 


Extract. 


Specific 


















Gravity 
at is''C. 


Per 

Cent 

by 

Weight 


Grams 

per 
100 cc. 


Gravity 
at is°C. 


Per 

Cent 

by 

Weight 


Grams 

per 
100 cc. 


Gravity 
at 15° C. 


Per 

Cent 

bv 

Weight 


Grams 

per 
100 cc. 


Gravity 
at 15° C. 


Per 

Cent 

by 

Weight 


Grams 

per 
100 cc. 


I .0260 


6.71 


6.88 


1 .0325 


8.27 


8.54 


1 .0390 


9-92 


10.31 


I.04SS 


<i.53 


12.05 


I .0261 


6.74 


6.92 


1.0326 


8.29 


8.56 


1 .0391 


9.95 


10.34 


I .0456 


II. 55 


12.08 


1 .0262 


6.77 


6,95 


1.0327 


8.32 


8.59 


1.0392 


9.97 


10.36 


I 0457 


11.57 


12.10 


1.0263 


6.80 


6.98 


1.0328 


8.34 


8.61 


1 .0393 


9.99 


10.38 


1 .0458 


11 .60 


12.13 


I .0264 


6.82 


7.00 


1.0329 


8.37 


8.65 


1.0394 


10.02 


10.41 


I .0459 


11.62 


12. IS 


1.0265 


6. 85 


7.03 


1.0330 


8.40 


8.68 


1.0395 


10.04 


10.44 


I .0460 


:i .65 


12. 19 


I .0266 


6.88 


7 .06 


1.0331 


8.43 


8.71 


I .0396 


10.06 


10.46 


I .0461 


II .67 


12.21 


1 .0267 


6.91 


7.09 


1.0332 


8.4s 


8.73 


1.0397 


10.09 


10.49 


I .0462 


H.70 


12.24 


1.0268 


6.93 


7.12 


I.0333 


8.48 


8.76 


1.0398 


10. 11 


10.51 


I .0463 


11.72 


12.26 


1.0269 


6.96 


7-15 


1.0334 


8.51 


8.79 


I 0399 


10. ij 


10.53 


1.0464 


11-75 


12.30 


I .0270 


6.99 


7.18 


1.033s 


8.53 


8.82 


I . 0400 


10. 16 


10.57 


1.046s 


11-77 


12.32 


I .0271 


7.01 


7.20 


I 0336 


8.56 


8.8s 


I .0401 


10.18 


10.59 


1 .0466 


11.79 


12.34 


I .0272 


7.04 


7-23 


1.0337 


8.59 


8.88 


I .0402 


10. 20 


10.61 


I .0467 


11.82 


12.37 


1.0273 


7.07 


7.26 


1-0338 


8.61 


8.90 


I .0403 


10. 23 


10. 64 


I .0468 


II .84 


12.39 


1,0274 


7. 10 


7.29 


1-0339 


8.64 


8.93 


I .0404 


10. 25 


10. 66 


I .0469 


II .87 


12.43 


10275 


7.12 


7.32 


1-0340 


8.67 


8.96 


I .0405 


10. 27 


10.69 


1.0470 


11 .89 


12.45 


1 .0276 


71S 


7-35 


I. 0341 


8.70 


9.00 


1 .0406 


10.30 


10.72 


1 0471 


11 .92 


12.48 


1.0277 


7.18 


7.38 


1.0342 


8.72 


9.02 


1 .0407 


10.32 


.10.74 


1.0472 


11.94 


12.50 


I .0278 


7.21 


7-41 


1.0343 


8.75 


90s 


1 .0408 


10.3s 


10.77 


1.0473 


II .97 


12.54 


1 .027g 


7.23 


7.43 


1.0344 


8.78 


9.08 


1 .0409 


10.37 


10.79 


1.0474 


11.99 


12.56 


1 .0280 


7.26 


7.46 


1.034s 


8.80 


9.10 


I .0410 


10.40 


10.83 


1.047s 


12.01 


12.58 


1 .0281 


7.28 


7.48 


1.0346 


8.83 


9.14 


I .0411 


10.42 


10.85 


1.0476 


12.04 


12.61 


1 .0282 


7.30 


7-51 


I.0347 


8.86 


9-17 


1 .0412 


10.45 


10.88 


1.0477 


12 .06 


12.64 


1.0283 


7-33 


7.54 


1.0348 


8.88 


9.19 


1.0413 


10.47 


10.90 


1.047S 


12.09 


12.67 


I .0284 


7.35 


7-56 


1.0349 


8.91 


9.22 


1.0414 


10.50 


10.93 


I .0479 


12. II 


12.69 


1 .0285 


7-37 


7-S8 


1.0350 


8.94 


9-25 


1.041s 


10.52 


10.96 


I .0480 


12.14 


12.72 


I .0286 


7.39 


7.60 


1.0351 


8.97 


9.28 


1 .0416 


10. 55 


10.99 


I .0481 


12.16 


12.74 


1 .0287 


7.42 


7.63 


1-0352 


8.99 


9-31 


1.0417 


10.57 


1 1 .01 


1 .04S2 


12.19 


12.78 


1 .0288 


7-44 


7.65 


1-03S3 


9.02 


9.34 


I .0418 


10.60 


II .04 


1.0483 


12.21 


12.80 


1.0289 


7-46 


7.68 


I-03S4 


9.05 


9-37 


1.0419 


10. 62 


11 .06 


1.0484 


12.23 


12.82 


I .0290 


7-48 


7-70 


1-0355 


9.07 


9-39 


1 .0420 


10.65 


11 . lo 


1.0485 


12.26 


12.85 


I .0291 


7-51 


7-73 


1-0356 


9.10 


9.42 


1,0421 


10.67 


11.12 


1.0486 


12.28 


12.88 


I .0292 


7-53 


7-7S 


I-03S7 


9-13 


9.46 


1 .0422 


10.70 


11. IS 


1.0487 


12.31 


12.91 


1.0293 


7-SS 


7-77 


1 0358 


9-15 


9-48 


1.0423 


10.72 


11.17 


1.0488 


12.33 


12.93 


1.0294 


7-57 


7-79 


1-0359 


9.18 


9-Si 


1.0424 


10.75 


11.21 


1 .0489 


12.36 


12.96 


1.0295 


7.60 


7.82 


1 .0360 


9.21 


9-54 


1.0425 


10.77 


11.23 


1 .0490 


12.38 


12.99 


I .0296 


7.62 


7.8s 


I. 0361 


9-24 


9-57 


I .0426 


10.80 


1 1 . 26 


1.0491 


12.41 


13.02 


1.0297 


7.64 


7.87 


1 .0362 


9. 26 


9.60 


1.0427 


10.82 


11.28 


1 .0492 


12.43 


13 04 


1.0298 


7.66 


7.89 


1.0363 


9-29 


9-63 


1.0428 


10.85 


11.31 


1.0493 


12.45 


13.06 


I .0299 


7.69 


7.92 


1.0364 


9-31 


9-65 


1.0429 


10.88 


11.35 


1.0494 


12.48 


13.10 


I .0300 


7.71 


7.94 


1.0365 


9.34 


9.68 


1.0430 


10.90 


11.37 


I. 049s 


12.50 


13.12 


I .0301 


7.73 


7.96 


1 .0366 


9.36 


9.70 


I. 0431 


10.93 


1 1 .40 


I .0496 


12.53 


13.15 


I .0302 


7-75 


7.98 


1.0367 


9.38 


9-72 


1.0432 


10.95 


11.42 


I .0497 


12.55 


13-17 


1-0303 


7-77 


8.01 


1.0368 


9.41 


9.76 


I -0433 


10.98 


1 1 .46 


I .0498 


12.58 


13-21 


1.0304 


7. So 


8.04 


1 .0369 


9-43 


9.78 


i-°434 


11 .00 


1 1. 48 


1.0499 


12.60 


13-23 


1.0305 


7.82 


8.06 


1.0370 


9-45 


0.80 


I -043s 


11.03 


11.51 


1 .0500 


12.63 


13-26 


1 .0306 


7.84 


8.06 


1.0371 


9.48 


9.83 


1-0436 


11 .05 


11.53 


I .0501 


1 2 . 6.5 


13.28 


1.0307 


7.86 


8.10 


1.0372 


950 


9.8s 


1-0437 


11 .08 


11 .56 


I .0502 


12.67 


13.31 


1.0308 


7.89 


8.13 


1-0373 


9.52 


9.88 


1-0438 


II . 10 


11.59 


1.0503 


12.70 


13-34 


1.0309 


7.91 


8.15 


1-0374 


9-SS 


9.91 


1-0439 


11.13 


11.62 


1.0504 


12.72 


13-36 


1.03:0 


7.93 


8.18 


1-0375 


9-57 


9-93 


1.0440 


11.15 


11.64 


1.0505 


12.75 


13-39 


1 .0311 


7.9s 


8.20 


1-0376 


9. 59 


9-95 


1.0441 


11.18 


II .67 


1 .0506 


12.77 


13.42 


1 .0312 


7.98 


8.23 


1-0377 


9.62 


9-98 


1.0444 


11 . 20 


II .70 


1.0507 


12.80 


13.45 


1-0313 


8. 00 


8.2s 


1-0378 


9.64 


10.00 


1.0443 


11 .23 


11.73 


I .0508 


12.82 


13.47 


1-0314 


8.02 


8.27 


1-0379 


9.66 


10.03 


1.0444 


II. 2S 


1I-7S 


1 .0509 


12.8s 


13.50 


I-031S 


8.04 


8.29 


1.0380 


9.69 


10.06 


1 .0445 


11 . 28 


11.78 


I .0510 


12.87 


13.53 


1-0316 


8.07 


8.33 


1.0381 


9.71 


10. oS 


1 .0446 


11.30 


11 .80 


1 .0511 


12.90 


13.56 


I-0317 


8.09 


8. 35 


1.0382 


9.73 


10.10 


1.0447 


11-33 


II. 84 


I. 0512 


12.92 


13.58 


1-0318 


8.11 


8.37 


1.0383 


9.76 


10.13 


I .0448 


II -35 


11.86 


1.0513 


12.94 


13.60 


I-0319 


8.13 


8.39 


1.0384 


9.78 


10.16 


1.0449 


11.38 


1 1. 89 


1.0514 


12.97 


13.64 


I -0320 


8.16 


8.42 


1.0385 


9.81 


10.19 


1.0450 


1 1 .40 


11.91 


I. 0515 


12.99 


13-66 


I. 0321 


8.18 


8.44 


1 .0386 


9.83 


10.21 


1. 045 1 


11-43 


11.95 


I .0516 


13.02 


13-69 


I. 0322 


8.20 


8.46 


1.0387 


9.85 


10.23 


I .0452 


II -45 


11.97 


1.0517 


13.04 


13-71 


1-0323 


8.22 


8.49 


1.0388 


9.88 


10. 26 


1.0453 


11.48 


1 2 . 00 


1 .0518 


13.07 


13-75 


1.0324 


8.2s 


8.52 


1.0389 


9.90 


10.29 


10454 


11 .50 


I 2.02 


1.0519 


13.09 


13-77 



584 



FOOD INSPECTION AND /IN A LYSIS. 
EXTRACT IN BEER WOKT— {Continued). 





Extract. 


Specific 


Extract. 


Specific 


Extract. 


Specific 


Extract. 


Specific 


















Gravity 


Per 


Grams 


Gravity 


Per 


Grams 


Gravity 


Per 


Grams 


Gravity 


Per 


Grams 


at i5°C. 


Cent 

by 

Weight 


per 
100 cc. 


at 15° C. 


Cent 

by 

Weight 


per 
100 cc. 


at 15° C. 


Cent 

bv 

Weight 


per 
100 cc. 


at 15° C. 


Cent 

bv 

Wei'ght 


per 
100 cc. 


I .0520 


13- 12 


13 80 


1.0585 


■ 4-75 


15.61 


I .0650 


16. 25 


17.31 


I .0715 


17.81 


19.08 


1 .0521 


i3-'4 


13.82 


I -0585 


..■.-78 


13.65 


1 .0651 


16. 27 


17-33 


1 .0716 


17.84 


19.12 


I .0522 


13.16 


13-85 


1-0587 


14-81 


15.68 


I .0652 


16.30 


17.36 


I. 0717 


17.86 


19.14 


I .0523 


13.19 


13-88 


1.0588 


14-83 


IS -70 


1.0653 


16.32 


17-39 


I .0718 


17.88 


19. 16 


1.0524 


13-21 


13-90 


1.0589 


14.86 


15-74 


I .0654 


16.35 


17.42 


1.0719 


17.90 


19.19 


I .0525 


13-24 


13-94 


1 .0590 


14.89 


15-77 


I 0655 


16.37 


17.44 


1 .0720 


17-93 


10.22 


1 .0526 


13- 26 


13.96 


I. 0591 


14.91 


15-79 


I .0656 


16.40 


17.48 


1 .0721 


17-95 


19.24 


I 0327 


13.29 


13-99 


1.0592 


14-94 


15.82 


I .0657 


16.42 


17.50 


1 .0722 


17-97 


19.27 


I .0528 


13.31 


14-01 


1.0593 


14.96 


15-85 


1 .0658 


16.45 


17.53 


I .0723 


17.99 


19.29 


1.0529 


13-34 


14-05 


1.0594 


14.99 


15-88 


1 .0659 


16.47 


17-56 


1.0724 


18.02 


19.32 


1.0530 


13.36 


14.07 


I. 0595 


15.02 


15-91 


1 .0660 


16.50 


17-59 


1.0725 


18.04 


19. 35 


I.OS3I 


13.38 


14.09 


1 .0596 


15-04 


15-94 


1 -0661 


16.52 


17-61 


1 .0726 


18.06 


19.37 


1.0532 


13-41 


14.12 


I.OS97 


15.07 


15-97 


I -066 2 


16.54 


17-63 


1 .0727 


18.08 


19.39 


I.OS33 


13-43 


14-1S 


I .0598 


15.09 


15-99 


1 -0663 


16.57 


17-67 


I .0728 


18.11 


19-43 


1.0534 


13.46 


14-18 


1.0599 


15.11 


16.02 


1 .0664 


16.59 


17.69 


I .0729 


18. .3 


19-45 


1.053s 


13-48 


14.20 


1 .0600 


1S-14 


16.05 


I .0665 


16.62 


17.73 


1.0730 


18. IS 


19.47 


I -0536 


13-SI 


14-23 


I .0601 


15-16 


16.07 


1 -0666 


16.64 


17.75 


1-0731 


18.17 


19.50 


I .0537 


13-53 


14- 26 


1 .0602 


IS-18 


16.09 


I -0667 


16.67 


17.78 


I .0732 


18.20 


19-53 


I .0538 


13-56 


14.29 


1 .0603 


I'S . 20 


16.12 


I .0668 


16.69 


17.80 


1-0733 


18.22 


19 55 


1.0539 


13.58 


14-31 


1 .0604 


15 23 


16.15 


I .0669 


16.72 


17.84 


1.0734 


18.24 


19-58 


I .0540 


13-61 


14-34 


1.0605 


IS. 25 


16.17 


I .0670 


16.74 


17.86 


1-0735 


1S.26 


19.60 


I. 0541 


13-63 


14-37 


1 .0606 


IS-27 


16 . 20 


1 .0671 


16.76 


17.88 


1 -0736 


18. 29 


19.64 


1 .0542 


13-66 


14.40 


1 -0607 


15-29 


16. 22 


I .0672 


16-79 


17-92 


1-0737 


18.31 


19.66 


1.0543 


13.68 


14.42 


1 .0608 


15-31 


16. 24 


1.0673 


16-81 


17-94 


I -0738 


.8.33 


19.68 


I.OS44 


13.71 


14.46 


1.0609 


15.34 


16. 27 


1.0674 


16.84 


17.98 


1.0739 


18.3s 


19.71 


1.054s 


13-73 


14.48 


I .0610 


15.36 


16.30 


1.0675 


16.86 


18.00 


1.0740 


18.38 


19.74 


1.0546 


13-76 


14.51 


1 .0611 


15.38 


16.32 


1 .0676 


1 6 . 80 


18.03 


I .0741 


18.40 


19-76 


I.OS47 


13.78 


14-53 


1 .0612 


15.40 


16-34 


I .0677 


16-91 


18.05 


I .0742 


18.42 


19-79 


I .054S 


13-81 


14-57 


1.0613 


15.43 


16-38 


I .0678 


16-94 


18.09 


1.0743 


18.44 


19.81 


1.0549 


13-83 


14-59 


1 .0614 


15-45 


16.40 


1 .0679 


16-96 


18.11 


1-0744 


18.47 


19.84 


1.0550 


13-86 


14-62 


1 .0615 


15-47 


16.42 


1.0680 


16-99 


18.15 


.1.0745 


18.49 


19-87 


I .0551 


13-88 


14-64 


1 .0616 


15-49 


16.44 


I .0681 


17 -01 


.8.17 


1.0746 


18.51 


19-89 


1 .0552 


13.91 


14-68 


1 .06x7 


15-52 


16-48 


I .0682 


17-03 


1S-19 


I .0747 


18.53 


19.91 


I.05S3 


13-93 


14-70 


1.0618 


15.54 


16-50 


1 .0683 


17-06 


18-23 


1 .0748 


18.55 


19-94 


I.05S4 


13.96 


14-73 


1 .0619 


15-56 


16.52 


1 .0684 


17-08 


18.25 


1.0749 


18.57 


19-96 


1.055s 


13-98 


14.76 


I .0620 


15-58 


16.55 


1-0685 


17.11 


18. 28 


1.0750 


18.59 


19-98 


I -0556 


14-01 


14.75 


1 .0621 


15-60 


16-57 


1-06S6 


17-13 


18-31 


I .0751 


18.62 


20-02 


1-0557 


14-03 


14.81 


I .0622 


15-63 


16-60 


I .06S7 


17-16 


18-34 


1.0752 


18.64 


20 -04 


I .055S 


14-06 


14-84 


1.0623 


15-65 


16.62 


1.0688 


17- 18 


18-36 


I .0753 


18.66 


20.07 


I.05S9 


14.08 


14-87 


I .0624 


15-67 


16.64 


I .0689 


17.21 


1S.40 


1.0754 


18.68 


20 .09 


1.0560 


14-11 


14.90 


1 .0625 


15.69 


16.66 


1 .0690 


17-23 


18-42 


1.075s 


18.70 


20-11 


r .0561 


14-13 


14.92 


1 .0626 


15.72 


16.70 


1 .0691 


17.25 


18.44 


I .0756 


18.72 


20- 14 


1.0562 


14. i6 


14-96 


1 .0627 


15-74 


16.73 


1 .0692 


17-28 


1 8. 48 


1-0757 


:8.74 


20. 16 


1 .0563 


14.18 


14-9S 


1 .0O28 


15-76 


16.75 


1.0693 


17-30 


18.50 


1.0758 


18.76 


20.18 


I .0564 


14.21 


15.01 


1.0629 


15.78 


16.77 


I .0694 


17-33 


18.53 


1.0759 


18.78 


20. 21 


1-0565 


14-23 


lS-03 


1.0630 


15.80 


16.80 


I .0695 


17-35 


18.56 


1 .0760 


18.81 


20. 24 


r.0566 


14- 26 


15-07 


I. 0631 


■ 5-83 


16.83 


1 .0696 


17.38 


18.59 


1 .0761 


18.83 


20. 26 


I .0567 


14-28 


15-09 


I .0632 


■ 5-8s 


16. 85 


1 -0697 


17.40 


18-61 


I .0762 


18.85 


20. 29 


1.0568 


14-31 


15-12 


1.0633 


15-87 


16.87 


1 .0698 


17-43 


18-65 


I .0763 


18.87 


20.31 


I .0569 


14-33 


IS-IS 


1.0634 


15.89 


16.90 


1 .0699 


17-45 


18-67 


1.0764 


18.89 


20.33 


1.0570 


14.36 


15.18 


1.0635 


15.92 


16.93 


1 .0700 


17.48 


18-70 


1.0765 


18.91 


20.36 


1-0571 


14-38 


15.20 


1 .0636 


15-94 


16.95 


1 .0701 


17.50 


18-73 


1 .0766 


J8.93 


20.38 


1.0572 


14.41 


15.23 


1.0637 


15.96 


1 6. 98 


1 .0702 


17.52 


18-75 


I .0767 


18.95 


20.40 


1.0573 


14-44 


15.27 


1.0638 


15.98 


17.00 


1.0703 


17.54 


18-77 


I .0768 


18-97 


20.43 


I. 0574 


14.46 


lS-29 


1.0&39 


16.01 


17.03 


1.0704 


17-57 


18-81 


1 .0769 


19.00 


20.46 


1.0575 


14.49 


15-32 


1 .0640 


16.03 


17.06 


1.0705 


1759 


18-83 


1.0770 


19.02 


20.48 


I .0576 


14-52 


15.36 


1 .0641 


16-05 


17.08 


1 .0706 


17.61 


18.85 


I. 0771 


19.04 


20.51 


I .0577 


14-54 


15-38 


I .0642 


16.07 


17. 10 


I .0707 


17.63 


18.88 


1.0772 


19.06 


20.53 


1.0578 


14-57 


15-41 


1.0643 


16.09 


17.12 


I .0708 


17.66 


18.91 


1.0-73 


19.08 


20.5s 


1.0579 


14-59 


15-43 


I . 0644 


16.12 


17. 16 


I .0709 


17.68 


18.93 


1.0774 


19. 10 


20.58 


1 .05S0 


14.62 


15-47 


1.064s 


16.14 


17.18 


1 .0710 


17.70 


18.96 


1.0775 


19.12 


20.60 


I.05S1 


14.65 


15.50 


1 .0646 


16.16 


17 . 20 


1 .071 1 


17.72 


18.98 


1.0776 


19.14 


20.03 


1.05S4 


14.67 


15-52 


1.0647 


16.18 


17.23 


I .0712 


17-75 


19.01 


1.0777 


19-17 


20.66 


I .05S3 


14.70 


15.56 


1.0648 


16.21 


17,26 


1.0713 


17-77 


19.04 


1.0778 


19.19 


20. 63 


I .0584 


14-73 


I5-S9 


5.0649 


16.23 


17. 2S 


1 .0714 


17-79 


19.06 


1.0779 


19-21 20.71 



ALCOHOLIC BEVERAGES. 



585 



EXTRACT IN BEER WORT— (Contimied). 





Extract. 


Specific 


Extract. 


Specific 


Extract. 


1 
Specific 


Extract. 


Specific 














1 


Gravity 


Per 


Grams 


Gravity 


Per 


Grams 


Gravity 


Per 


Grams 


Gravity 


Per 


Grams 

per 
100 cc. 


at 15° C. 


Cent 

by 

Weight 


per 
100 cc. 


at is°C. 


Cent 

by 

Weight 


per 
100 cc- 


at 15° C. 


Cent 

by 

Weight 


per 
100 cc. 


at is'C. 


Cent 

by 

Weight 


I .0780 


19- 23 


20.73 


1.084s 


20.70 


22.45 


I .0910 


22. ig 


24. 21 


I .0975 


23.59 


25.89 


I. 0781 


19. 25 


20.75 


I .0846 


20,73 


22.48 


I .0911 


22.21 


24.24 


I .0976 


23.61 


25.92 


1 ,0782 


19.27 


20.78 


1.0847 


20, 75 


22.50 


I .0912 


22.23 


24. 26 


1.0977 


23.63 


25.94 


1.0783 


19.29 


20.80 


1.0S48 


20,77 


22,53 


1.0913 


22. 26 


24.29 


I .0978 


23-65 


2597 


1.0784 


19-31 


20.82 


1 .0S49 


20,79 


22,55 


1.0914 


22. 28 


24-31 


1.0979 


23-67 


25.99 


1.078s 


19-33 


20.8s 


I ,0850 


20.81 


22.58 


1.091S 


22, 30 


24 ■ 34 


I .0980 


23.69 


26.01 


1.0786 


19-36 


20.88 


i-oSsr 


20.83 


22.61 


I .0916 


22.32 


24.37 


I .ogSi 


23. 71 


26.04 


1.0787 


19-38 


20. go 


I ,0852 


20.86 


22.64 


I .0917 


22.34 


24-39 


I .0982 


23-73 


26.06 


1.0788 


19.40 


20.93 


I. 0853 


20. 88 


22.66 


I . 09 1 8 


22.37 


24.42 


I .0983 


23-76 


26.09 


I .0789 


19.42 


20.9s 


i-o8s4 


20.90 


22.68 


I .0919 


22.39 


24.44 


1 .09S4 


23.78 


26. II 


I .0700 


19.44 


20.98 


1.085s 


20.93 


22,72 


I .0920 


22.41 


24.47 


1-0985 


23.80 


26. 14 


I-O70I 


19.46 


21 .00 


I .0S56 


20.95 


22,75 


I .0921 


22.43 


24.49 


I .09S6 


23.82 


26. 17 


1.0792 


19.49 


21 .03 


1.0857 


20,98 


22.78 


I .0922 


22.45 


24.51 


I .0087 


23.84 


26. 19 


1.0793 


19-S1 


21 .06 


1,0858 


21 ,OI 


22.81 


1.0923 


22 48 


24-54 


I. 0988 


23,86 


26.22 


1.0794 


19-53 


21,08 


I ,0850 


21 .04 


22.84 


1.0924 


22.50 


24-56 


I .0989 


23-88 


26. 24 


1.079s 


19,56 


21.11 


I .0860 


21 .06 


22.87 


I .0925 


22.52 


24.60 


I .0990 


23.90 


26. 27 


I .0796 


19. 58 


21 . 14 


I -0861 


21 .09 


22 .90 


I .0926 


22.54 


24.62 


I .0991 


2392 


26.30 


1.0797 


19.60 


21 . 16 


I ,0862 


21 . II 


22.93 


1.0927 


22.56 


24.64 


I .0992 


23-94 


26. 32 


1.0798 


19.63 


21 . 20 


1.0863 


21.13 


22 , 96 


I .0928 


22.59 


24.67 


I .0993 


23-97 


26.3s 


1.0799 


19-65 


21 . 22 


I ,0864 


21 . lO 


22,99 


I .0929 


22.61 


24-70 


1.0994 


23 -99 


26.37 


I .0800 


19-67 


21.24 


1,0865 


21 . 19 


23,02 


1.0930 


22.63 


24.73 


I -0995 


24.01 


26, 40 


I .0801 


19.70 


21.28 


I ,0866 


21 . 22 


23.06 


1-0931 


22,65 


24.76 


I .0996 


24-03 


26,42 


i.o8o2 


19.72 


21 .30 


I ,0867 


21. 25 


23,09 


1-0932 


22, 67 


24.78 


1.0997 


24-05 


26,44 


1.0803 


19-74 


21.33 


1,0868 


21.28 


23.12 


1-0933 


22,69 


24.81 


I .0998 


24.07 


26.47 


I .0804 


19-77 


21.36 


I .0869 


21 , 30 


23-15 


1.0934 


22.71 


24-83 


I .0999 


24.09 


26.49 


I .0805 


19.79 


21.38 


I .0870 


21,33 


23-18 


1.0935 


22.73 


24.86 


.1 . 1000 


24. 1 r 


26. 52 


I .0S06 


19.81 


21.41 


I .087 r 


21.35 


23- 21 


1.0936 


22.75 


24-89 


I . 1001 


24-13 


26.55 


I .0807 


19-S4 


21.43 


I .0872 


21.37 


23.23 


1-0937 


22,77 


24-91 


I . 1002 


24-15 


26.57 


I.0S08 


19.86 


21 .46 


1.0873 


21.39 


23,26 


1.0938 


22.80 


24-93 


I . 1003 


24-17 


26.60 


I .0809 


19.88 


21.49 


1-0874 


21 ,41 


23.28 


1.0939 


22.82 


24.96 


1 . 1004 


24.19 


26.62 


1. 0810 


19.91 


21. S2 


1.087s 


21 -43 


23.31 


1 .0940 


22.84 


24.99 


I . loos 


24. 21 


26.65 


I .0811 


19-93 


21. SS 


I .0876 


21 ,45 


23-33 


I. 0941 


22.86 


25.01 


I . 1006 


24. 23 


26.68 


1 .0812 


19.96 


21.58 


1-0877 


21,47 


23-36 


1.0942 


22.88 


25.03 


I . 1007 


24- 25 


26.70 


1. 0813 


19-98 


21 .60 


1,0878 


21 ,49 


23.38 


1.0943 


22.90 


25.06 


I . 1008 


24, 28 


26. 73 


1 .0814 


20.00 


21.63 


I .0879 


21, SI 


23.40 


1.0944 


22 .92 


25.08 


I . 1009 


24.30 


26.7s 


I .0815 


20.03 


21.66 


I ,0880 


21,54 


23.43 


1.094s 


22.94 


25. II 


I . 1010 


24.32 


26.78 


1. 0816 


20.0s 


21 .69 


I .0881 


21,56 


23-45 


I .0946 


22,96 


2514 


1 . lOII 


24.34 


26.81 


1 .0817 


20.07 


21.71 


1.0882 


21,58 


23-48 


I .0947 


22.98 


25-16 


I .1012 


24.36 


26.83 


J. 0818 


20. 10 


21.74 


I ,o88! 


21 ,60 


23.50 


I .0948 


23-00 


25-18 


I . IOI3 


24-39 


26.86 


1 .0819 


20. 12 


21-77 


I .0884 


21 ,62 


2352 


1.0949 


23-03 


25.21 


I . IOI4 


24.41 


26,88 


1 .0820 


20. 14 


21 .79 


I .0R83 


21 ,64 


23. SS 


I .0950 


23-05 


25.24 


I . lois 


24.43 


26.91 


1 .0821 


20. 1 7 


21 .83 


1.0886 


21 ,66 


23-58 


1-0951 


23,07 


25. 26 


1 . IOI6 


24-45 


26,93 


1.0822 


20. 19 


21 .85 


I .0887 


21,68 


23-60 


I-09S2 


23. 10 


25.29 


I . 1017 


24.47 


26,95 


1.0823 


20. 21 


21 .87 


1.08S8 


21 ,71 


23-63 


I -0953 


23.12 


25-31 


I . IOI8 


24.49 


26,98 


I .0824 


20.24 


21 .91 


1 .0889 


21 ,73 


23.66 


1.0954 


23.14 


25.34 


1 . 1019 


24-51 


27.00 


1.082s 


20.26 


21.93 


I .0S90 


21-75 


23.69 


I-09S5 


23-16 


25-37 


1 . 1020 


24-53 


27,03 


1.0826 


20.28 


21 .96 


1 .0891 


21.77 


23.72 


I .0956 


23-18 


25-39 


I . 1021 


24 ■ 5 5 


27 .06 


1.0827 


20.31 


21.99 


I .0892 


21 -70 


23.74 


1.09S7 


23.20 


25-42 


I . 1022 


24- 57 


27 .08 


1.0828 


20.33 


22.01 


I .0S93 


21 .82 


23-77 


I .0958 


23-23 


25-45 


I . 1023 


24, 60 


27.11 


1 .0829 


20.3s 


22.04 


I .0S94 


21,84 


23.79 


1.0959 


23-2S 


25-47 


I . 1024 


24,62 


27.14 


I .0830 


20.37 


22.06 


I .0895 


21,86 


23.82 


I .0960 


23.27 


25-50 


I . I02S 


24,64 


27.17 


1 .0831 


20.39 


22.08 


I .0896 


21 ,89 


23.8s 


I .0961 


23.29 


25-53 


I . 1026 


24.66 


27. 19 


1 .0832 


20.41 


22.11 


i.oS)7 


21.91 


23.87 


I .0962 


23.31 


23-55 


I . 1027 


24.68 


27.21 


1.0833 


20.43 


22,13 


1.0898 


21 ,93 


23.90 


I .0963 


23 . 33 


25-58 


I . 1028 


24.70 


27.24 


1.0834 


2C .46 


22. 16 


I .0899 


21,96 


23.93 


1.0964 


23. 35 


25.60 


1. 1029 


24.72 


27.26 


1 .0833 


20.48 


22. 19 


I .0900 


21 ,98 


23.96 


I .0965 


23.37 


25-63 


I. 1030 


24.74 


27-29 


1.0836 


20.50 


22.21 


I .0901 


22,00 


23.98 


I .0966 


23.39 


25-66 


I.IO3I 


24.76 


27 .32 


1.0837 


20.52 


22.24 


I .0902 


22.02 


24.01 


1 .0967 


23.41 


25-68 


1.1032 


24,78 


27 .34 


1.0838 


20.54 


22. 26 


I .0903 


22.04 


24.03 


1 .0968 


23.44 


25.71 


1-I033 


24,81 


27.37 


I.0S39 


20.56 


22. 29 


1.0904 


22.06 


24.0s 


1 .0969 


23.46 


25.73 


1.1034 


24-83 


27.39 


I.0S4O 


20. SO 


22.32 


I .0905 


22.08 


24.08 


1.0970 


23.48 


25-76 


I-I03S 


24,8s 


27 -42 


1.0841 


20. 6j 


22.35 


1.0906 


22 . 10 


24. 11 


I. 0971 


23.50 


25-79 


I . 1036 


24.87 


27 -45 


I.0S42 


20.64 


22.38 


1 .0907 


22. 12 


24. 13 


1.0972 


23-52 


25.81 


I.I037 


24.89 


27.47 


1.0843 


20. 61) 


22.40 


1 .0908 


22.15 


24.16 


I .0973 


23-55 


25. 84 


I . 1038 


24.92 


27.50 


1.0844 


20.0s 


22 .42 


1 .0909 


22.17 


24.18 


1.0974 


23-57 


25.86 


I 1039 


24-94 


27-53 



586 



FOOD INSPECTION /1ND /IN/I LYSIS. 
EXTRACT IN BEER ViOV^T— {Concluded). 





Extract. 


specific 


Extract. 


Specific 


Extract. 


Specific 


Extract. 


Specific 


















Gravity 


Per 


Gratns 


Gravity 


Per 


Grams 


Gravity 


Per 


Grams 


Gravity 


Per 


Grams 


at 15° C. 


Cent 


per 


at 15° C. 


Cent 


per 


at 15° C. 


Cent 


per 


at is" C- 


Cent 


per 




by 
Weight 


100 cc. 




by 
Weight 


100 cc. 




by 
Weight 


100 cc. 




by 
Weight 


100 cc. 


I . 1040 


24.96 


27.56 


1.1095 


26. 16 


29.03 


1.1150 


27.29 


30.43 


I -120S 


28.38 


31.81 


1 . 1041 


24.98 


27.58 


1 . 1096 


26.18 


29.06 


1.1151 


27-31 


30.4s 


I . 1206 


28.40 


31.83 


I . 1042 


25.00 


27.60 


1 .1097 


26. 20 


29.08 


1.1152 


27-33 


30.47 


1 . 1 207 


28.42 


31.86 


I .1043 


25.03 


27-63 


1 .1098 


26.23 


29-11 


I.IIS3 


27-35 


30.50 


I .1208 


28.44 


31.88 


I. 1044 


25.0s 


27.66 


1.1099 


26.2s 


29-13 


I.1154 


27-37 


30.52 


1 . 1209 


28.45 


31.90 


1.104s 


25.07 


27.69 


I .1100 


26. 27 


29.16 


1.115s 


27.38 


30.55 


I . 1210 


28.48 


31.93 


I . 1046 


25.09 


27.72 


I . IIOI 


26. 29 


29.19 


1.1156 


27.40 


30.57 


I . 1211 


28.50 


31.95 


I. 1047 


25 . 11 


27-74 


I .1102 


26.31 


29. 21 


1.1157 


27-42 


30.59 


I . 1212 


28.52 


31.98 


I . 1048 


25. 14 


27.77 


I.IIO3 


26.33 


29.24 


1.1158 


27-44 


30.62 


1.1213 


28.54 


32.00 


1.1045 


25.16 


27.79 


1 .1104 


26.35 


29.26 


I.IIS9 


27-46 


30.64 


1 . 1314 


28.56 


32.03 


1.1050 


25.18 


27.82 


1 .1105 


26.37 


29.29 


1 . II 60 


27.48 


30.67 


I . 1215 


28.58 


32.05 


1 .1051 


25. 20 


27.8s 


I . 1106 


26.39 


29.32 


I . 1161 


27 -so 


30.69 


I . 1216 


28.60 


32.08 


1.1052 


25.22 


27.87 


1 . 1107 


26.41 


29.34 


1.1162 


27-52 


30.72 


I . 1217 


28.62 


32.11 


I. 1053 


25. 24 


27.90 


I. 1108 


26.44 


2937 


1.1163 


27-54 


30.7s 


I. 1218 


28.64 


32.13 


1.1054 


25.27 


27.93 


I . 1109 


26.46 


29.39 


1.1164 


27.56 


30.77 


I . 1219 


28.66 


32. IS 


I. 1055 


25.29 


27.96 


1 .1110 


26.48 


29-42 


1.1165 


27.58 


30.80 


1 .1220 


28.68 


32.18 


1 . 1056 


25-.^ I 


27-98 


I . nil 


26.50 


29-44 


I . I T 66 


27.60 


30.82 


I . 1221 


28.70 


32. 20 


I.IOS7 


25.3.1 


28.00 


T . III2 


26. 52 


29.46 


1 .1167 


27.62 


30.8s 


I . 1222 


28.72 


32.23 


1 . 1058 


25.35 


28.03 


I.III3 


26.54 


29.49 


1.1168 


27.64 


30.87 


1 .1223 


28.74 


32.25 


1,1059 


25.38 


28.06 


I . III4 


26.56 


29-51 


1 . 1169 


27.66 


30.89 


1. 1224 


28.76 


32.27 


1 . 1060 


25.40 


28.09 


I. HIS 


26.58 


29-54 


I . 1170 


27.68 


30.92 


1 . 1225 


28. 78 


32.30 


1 . 1061 


25.42 


28.12 


1 . 1116 


26.60 


29-57 


1.1171 


27.70 


30.94 


I . 1226 


28.80 


32.32 


I . 1062 


25.44 


28. 14 


1.1117 


26.62 


29-59 


1.1172 


27.72 


30.97 


I . 1227 


28.82 


32.35 


I . 1063 


25.46 


28-17 


1.H18 


26.64 


29.61 


I- 1173 


27-74 


31 .00 


I. 1228 


28.84 


32.37 


I .1064 


25.48 


28.19 


1.1119 


26.66 


29.64 


1-1174 


27-76 


31.02 


1. I22g 


28.86 


32.40 


I . 1065 


25.50 


28.22" 


1. 1120 


26.68 


29.67 


I-I175 


27-78 


31.05 


I. 1230 


28.88 


32.43 


I . 1066 


25.52 


28.25 


1.1121 


26.70 


29.69 


I- 1176 


27. So 


31 .07 


I .1231 


28. 90 


32.4s 


I. 1067 


25.54 


28.27 


1 .1122 


26.72 


29.71 


I-1177 


27.82 


31-09 


I . 1232 


28.92 


32.48 


1.1068 


25.57 


28.30 


1.1123 


26.7s 


29.74 


1.1178 


27-84 


31.12 


1.1233 


28.94 


32 -SO 


1 . 1069 


25.59 


28.32 


1.1124 


26.77 


29.77 


1.1179 


27.86 


31-1S 


1.1234 


28.96 


32.53 


1.1070 


25.61 


28.35 


1.1125 


26.79 


29.80 


1.1180 


27. 88 


31 -18 


1-1235 


28.98 


32.56 


1 . 1071 


25.63 


28.38 


1 . 1126 


26.81 


29.83 


l.llSl 


27-90 


31-20 


I - 1236 


29.00 


32-58 


1 . 1072 


25.65 


28.40 


1.1127 


26.83 


29.85 


1.1182 


27-92 


3123 


1-1237 


29.02 


32.60 


1. 1073 


25.67 


28.43 


1. 1 1 28 


26.85 


29.88 


1. 1 183 


27-94 


31.25 


I -1238 


29.04 


32.63 


1.1074 


25.69 


28.4s 


1. 1 1 29 


26.87 


29.90 


1.1184 


27-96 


31.27 


I. 1239 


29.06 


32.6s 


1. 1075 


25.71 


28.48 


I .1130 


26.89 


29.93 


1-1185 


27-98 


31.30 


I . 1240 


29,08 


32.68 


1 . 1076 


25.73 


28. SI 


1.1131 


26.91 


29-95 


1.1186 


28. 00 


31.32 


1 .1241 


29. 10 


32.71 


1.1077 


25.75 


28.53 


1.1132 


26.93 


29-97 


1 .1187 


28.02 


31.35 


I . 1242 


29.12 


32.73 


1 . 1078 


25.78 


28.56 


1.1133 


26.95 


30.00 


1.1188 


28.04 


31.37 


1.1243 


29.14 


32.76 


1. 1079 


25.80 


28.58 


1.1134 


26.97 


30.02 


I. 1189 


28.07 


31.40 


I. 1244 


29.16 


32.78 


1 .1080 


25.82 


28.61 


1.1135 


26.99 


30.06 


I . 1190 


28.09 


31.43 


1.1245 


20.18 


32.81 


1.1081 


25.84 


28.64 


1. 1 1 36 


27.01 


30-08 


1 . 1 191 


28.11 


31.45 


1 . 1246 


29. 20 


32.83 


1 . 1082 


25.86 


28.66 


1.1137 


27-03 


30-10 


I .1192 


28.13 


31.48 


1.1247 


29.22 


32. 86 


1.1083 


25.89 


28.69 


1.1138 


27-05 


30.13 


1.1193 


28.15 


31. 51 


1. 1 248 


29.24 


32.89 


1.1084 


25.91 


28.72 


1.1139 


27.07 


30.1s 


1. 1 194 


28.17 


31.53 


1.1249 


29.26 


32.91 


1 . 1085 


25.93 


28.75 


1 .1140 


27-09 


30.18 


1.1195 


28-19 


31.56 


1. 1250 


29.28 


32.94 


1. 1086 


25.96 


28.78 


1.1141 


27.11 


30.20 


I .1196 


28.21 


31-59 


I.I2SI 


29.30 


32.96 


1 . 1087 


25. 98 


28.80 


1 .1142 


27-13 


30.22 


1.1197 


28. 23 


31 .61 


1.1252 


29.32 


32.99 


1.1088 


26.01 


28.83 


1. 1 143 


27-15 


30.25 


1. 1 1 98 


28.25 


31.63 


1.12S3 


29.34 


33.02 


1.1089 


26.03 


28.86 


I. 1144 


27.17 


30.27 


I. 1199 


28.27 


31.65 


1. 1254 


29.36 


33.04 


I . lOQO 


26.05 


28. 89 


1.1145 


27-19 


30.31 


I .1200 


28.28 


31.68 


I. 1255 


29.38 


33.07 


1 . lOQI 


26.07 


28.92 


1 . 1 146 


27 . 21 


30.33 


1.1201 


28.30 


31.70 


1 .1256 


29.40 


33.09 


1 . 1092 


26.09 


28.94 


I. 1147 


27-23 


30-35 


1 .1202 


28.32 


31-73 


I. 1257 


29.42 


33.12 


I. 1093 


26.12 


28.97 


1.1148 


27.25 


30-37 


1.1203 


28.34 


31.75 


1.1258 


29.45 


33.14 


1.1094 


26,14 


29.00 


1.1149 


27.27 


30.40 


z .1204 


28.36 


31.78 


I.H59 


29.47 


33.17 



ALCOHOLIC BEVERAGES. 

are ascertained. This figure is added to the " 
the "original gravity of the wort." 



587 
extract gravity" to find 



SUGAR USED UP IN FERMENTATION. 



°^- 






















SX.2 


0.0000 


O.OOOI 


0.0002 


0.0003 


0.0004 


0.0005 


0.0006 


0.0007 


0.0008 


0.0009 


0.000 




0.0003 


0.0006 


0.0009 


0.0012 


0.0015 


0.0018 


0.0021 


0.0024 


0.0027 


.001 


.0030 


-°°33 


.0037 


.0041 


.0044 


.0048 


.0051 


■°°5S 


.0059 


.0062 


.002 


.0066 


.0070 


.0074 


.0078 


.0082 


.0086 


.0090 


.0094 


.9098 


.0102 


.003 


.0107 


.0111 


.0115 


.0120 


.0124 


.0129 


•°i33 


.0138 


.0142 


.0147 


.004 


.0151 


-0155 


.0160 


.0164 


.0168 


.0173 


.0177 


.0182 


.01S6 


.oigi 


.005 


•0195 


.0199 


.0204 


.0209 


.0213 


.0218 


.0222 


.0227 


.0231 


.0236 


.006 


.0241 


-0245 


.0250 


.0255 


.0260 


.0264 


.0269 


.0274 


.0278 


-0283 


.007 


.0288 


.0292 


.0297 


.0302 


.0307 


.0312 


•0317 


.0322 


.0327 


■0332 


.008 


•0337 


-0343 


.0348 


•0354 


-°359 


■0365 


.0370 


■0375 


.0380 


.0386 


.oog 


■0391 


•°397 


.0402 


.0407 


.0412 


.0417 


.0422 


.0427 


.0432 


■0437 


.010 


.0442 


■ 0447 


.0451 


.0456 


.0460 


.0465 


.0476 


-0475 


.04S0 


.0485 


.on 


.0490 


.0496 


-0501 


.0506 


• 05 1 2 


.0517 


.0522 


.0527 


■°533 


.0538 


.012 


-0543 


.0549 


-<"554 


-0559 


.0564 


.0569 


•0574 


.0579 


-0S84 


.0589 


.013 


.0594 


.0600 


.0605 


.0611 


.0616 


.0622 


.0627 


■0633 


.0638 


.0643 


.014 


.0648 


.0654 


.0659 


.0665 


.0471 


.0676 


.0682 


.0687 


.0693 


.0699 


-oiS 


.0705 


.0711 


.0717 


.0723 


.0729 


-073s 


.0741 


•0747 


-07S3 


■0759 



Example. — Suppose the "extract gravity" is 1.0389 and the specific 
gravity of the alcoholic distillate is 0.9902, both at 15.6. Then i —0.9902 = 
0.0098, the "degree of spirit indication." From the above table the cor- 
responding "degree of gravity lost" is found to be 0.0432. 

0.0432+1.0389 = 1.0821, the original gravity of the wort. 

The calculation in the above simplified form is accurate for normal 
beer wherein the free acid present, expressed as acetic, does not exceed 
0.1%. In case of beer that has developed free acid much in e.xcess of 
the above hmit, a correction should be added to the degrees of spirit 
indication. This correction, which in practice it is rarely necessary to 
apply except in extreme cases of old or sour beer, is calculated as follows: 

If a represents the grams of free acid (as acetic) in 100 cc, then the 
correction to be added to the spirit indication = o.ooi3a — 0.00014. 

Example. — Supposing the "extract gravity" to be 1.0413, the specific 
gravity of the alcoholic distillate to be 0.9890, and the free acid as acetic 
to be 0.35%. Then 1—0.989=0.0110, the degree of spirit indication. 

0.35X0.0013 — 0.00014=0.0003, correction to be added to the spirit 
indication. 

0.0110 + 0.0003 = 0.0113, corrected spirit indication. 



588 FOOD INSPECTION AND ANALYSIS. 

From the above table the corresponding degrees of gravity lost are 
0.0506: 

0.0506+1.0413=1.0919, the original gravity of the wort. 

Determination of Total, Fixed, and Volatile Acids. — A measured 
volume of the beer, say 10 cc, is freed from carbon dioxide by bringing 
to boiling. It is then cooled and titrated with tenth-normal sodium 
hydroxide, using neutral litmus solution as an indicator. Each cubic 
centimeter of tenth-normal alkali is equivalent to 0.009 gram of lactic 
acid, in which the total acidity is usually expressed. 

Fixed acid, also expressed as lactic, though small quantities of suc- 
cinic, tannic, and malic acids are usually also present, is determined as 
follows: Dealcoholize a measured amount of the beer, say 10 cc., by 
evaporation to one-fourth its volume, dilute with vv'ater to the original 
volume, and titrate with tenth-normal alkali, as before. 

Volatile acid is expressed as acetic, and is usually calculated by dif- 
ference between total and fixed acid. Each cubic centimeter of tenth- 
normal alkali is the equivalent of 0.006 gram acetic acid. 

Determination of Proteids. — Fifty cc. of the beer are first treated 
with 5 cc. of dilute sulphuric acid, and concentrated by boiling to syrupy 
consistency. Then proceed by the Gunning method, p. 61. Nx6.25 = 
proteids. 

Determination of Phosphoric Acid. — Unless the sample is very dark- 
colored, sufficiently close results can usually be obtained by direct titra- 
tion of the beer itself with uranium acetate solution. For very accurate 
results the ash should be used. Prepare a solution of uranium acetate of 
such strength that 20 cc. will correspond to o.i gram P2O5. This solution 
is best standardized against pure, crystallized, imcflloresced, powdered 
hydrogen sodium phosphate, 10.085 grams of which are dissolved in 
water and made up to a liter. 50 cc. of this solution contains o.i gram 
phosphoric anhydride, if the salt is pure. If the solution is of proper 
strength, 50 cc. evaporated to drj-ness and ignited in a tared platinum 
dish should have an ash weighing 0.1874 gram. For preliminary trial 
about 35 grams of uranium acetate are dissolved in water, 25 cc. of glacial 
acetic acid, or its equivalent in weaker acid added, and the solution made 
up to a liter with water. 

To standardize, 50 cc. of the standard phosphate solution prepared 
as above are heated to 90° or 100° C, and the uranium solution run in 
from a burette till the resulting precipitate of hydrogen uranium phos- 
phate is complete. The end-point is determined by transferring a few 



ylLCOHOUC BEyER/IGES. 589 

drops of the solution to a porcelain plate, and touching with a drop of 
freshly prepared potassium ferrocyanide solution. When the slightest 
excess of uranium acetate has been added, a reddish-brown color is pro- 
duced by the ferrocyanide. The uranium acetate solution is purposely 
made rather stronger than necessary at first, and by repeated trials is 
brought by dilution with water to the required strength (20 cc. equivalent 
to 50 cc. of the phosphate solution). 

Fifty cc. of the beer are heated to 90° or 100° C. and titrated with 
the uranium acetate solution under the same conditions and in precisely 
the same manner as when standardizing that solution. Each cubic centi- 
meter of the uranium acetate corresponds to 0.01% of P2O5. 

For tlie phosphoric acid determination in the ash, 50 cc. of the beer 
are incinerated in the regular manner, and the ash moistened with con- 
centrated hydrochloric acid. The acid is then evaporated off on the 
water-bath, after which the ash is boiled with 50 cc. of distilled water, and 
titrated with the standard uranium solution. 

Determination of Carbon Dioxide.* — In the case of beer and other 
carbonated drinks put up in corked bottles, the carbon dioxide may be 
readily determined by piercing the cork with a metal champagne tap, 
which is connected by a flexible tube, first with a safety flask and then 
with an absorption apparatus somewliat after the style of that used in 
the determination of carbon dioxide in baking powder, the liberated 
carbon dioxide being absorbed for weighing in a concentrated solution 
of potassium hydroxide contained in a tared Liebig bulb. The beer- 
bottle thus connected is immersed in a vessel of water, which is heated 
over a gas-flame, after all the carbon dioxide that will escape spontaneously 
has been allowed to do so. Before weigliing the absorbed carbon dioxide, 
the beer-bottle is replaced by a soda-lime tube, and a current of air dravwi 
through tlie tubes. 

Beer and ale put up in bottles having patent metallic or rubber stoppers 
cannot thus be treated. In this case a measured quantity, say 200 cc, 
of the sample is transferred as quickly as possible to a large flask pro- 
vided with an outlet-tube having a glass stopper, tliis being connected 
up with the safety-flask and absorption-tubes. In this case heat may be 
directly, though cautiously, applied to the flask containing the beer by 
means of a gas-flame, after all the carbon dioxide has gone over that will 
do so spontaneously. Exactly the same apparatus as that shown in Fig. 

* U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 95. 



59° FOOD INSPECTION AND /IN/1LYSIS. 

65 may be used to advantage for determination of carbon dioxide in beer, 
except that a larger distilling-flask should be used in the case of beer. 

Detection of Bitter Principles. — Elaborate schemes have been worked 
out for the systematic treatment of beer and ale for bitter principles. Nearly 
all of these are complicated and somewhat unsatisfactory. The presence 
of alkaloids in malt liquors, deliberately introduced during the process 
of manufacture, is now so rare that the analyst need seldom look for them, 
except in cases of suspected poisoning, when the scheme of Dragendorf * 
or of Otto-Stas should be employed. While it is somewhat difficult to 
positively identify the various alkaloids, it is usually easy to prove their 
absence in clear solutions, if on treatment with either of the general 
alkaloidal reagents, Mayer's solution (Reagent No. 170), or iodine in potas- 
sium iodide (Reagent No. 143), no precipitate is formed. 

It is comparatively easy to prove the mere presence or absence of hop 
substitutes. The bitter principle of hops is readily soluble in ether, 
when a sample of the beer evaporated to syrupy consistency is extracted 
therewith, while the bitters of quassia and aloes, common hop substitutes, 
are insoluble in ether. Though many varieties of bitters might be em- 
ployed that are soluble in ether, the absence of a bitter taste from the 
ether extract is evidence of the absence of hops. 

The most marked difference analytically between hops and their 
substitutes in malt liquors lies in the fact that the bitter principle of hops 
is completely precipitated therefrom by treatment of the beer with lead 
acetate (either basic or neutral), leaving no bitter taste in the filtrate 
after concentration, while if any of the hop substitutes are present, the 
concentrated filtrate from the lead acetate treatment will have a bitter 
taste. The excess of lead should be removed from the filtrate, before 
concentration and tasting, by treatment with hydrogen sulphide. If the 
residue from the ether or chloroform extraction of the concentrated filtrate 
from a beer after treatment with lead acetate be found to be bitter, there 
is positive evidence that a foreign substitute has been employed. 

The following are characteristic reactions that may help to identify 
some of the common hop substitutes. f 

Quassiin is readily soluble by chloroform from acid solution. If a 
residue containing quassiin be moistened with a weak alcoholic solution 
of ferric chloride and gently heated, a marked mahogany-brown color- 
ation is produced. 

* Gerichtlich Chemische Ermittelung von Giften, St. Petersburg, 1876. 
t Allen, Analyst, 12, 1887, p. 107. 



ALCOHOLIC BE^ER/iGES. 59' 

On treatment of quassiin with bromine and sodium hydroxide or 
ammonia, a bright-yellow color is shown. 

Chirelta is readily dissolved by ether from its aqueous solution. Its 
ether residue, when treated with bromine and ammonia, gives a straw 
color, slowly changing to a dull purple-brown. This is not true of 
its chloroform residue, so that it is not to be mistaken for quassia 
(Allen). 

Gentian Bitter may be extracted by treatment of the acid liquor with 
chloroform. When the residue containing gentian bitter is treated with 
concentrated sulphuric acid in the cold, no color is produced, but on 
warming gently a carmine-red color is shown; if further treated with 
ferric chloride solution, a green-brown color is formed. 

Aloes. — ^This substance is separated from beer by treating the dried 
residue from 200 cc. of the beer with warm ammonia, filtering, cooling, 
and treating the filtrate with hydrochloric acid. The resin of aloes is 
precipitated and collected on a filter. It is insoluble in cold water, ether, 
chloroform, or petroleum ether, but is soluble in alcohol. It has a very 
characteristic odor, which serves to identify it. The hot-water solution 
gives a curdy precipitate on treatment with lead acetate. 

Capsicin is extracted by treatment of the acid liquor with chloroform. 
It is recognizable by its sharp, pungent taste. 

Detection of Arsenic— 5_v the Marsh Method. — Measure 100 cc. of 
the beer (freed from carbon dioxide by agitation) into a seven-inch porce- 
lain evaporating-dish, add 20 cc. pure concentrated nitric acid, and 3 cc. 
pure concentrated sidphuric acid, and cautiously heat till vigorous chemi- 
cal action sets in, accompanied by frothing and swelling of the beer. Turn 
the flame low or remove it altogether, and stir vigorously till the frotliing 
ceases, after which the liquid may be boiled freely. At this stage 
transfer to a large casserole, and continue the boiling till nearly all 
the nitric acid is driven off. Then, holding the casserole by the handle, 
continue the heating till the mass chars and the fumes of sulphuric acid 
are given off, giving the casserole a rotary motion to prevent sputtering. 
The residue should be reduced to a drj', black, pulverulent char soon after 
the sulphuric acid fumes begin to come off freely. If still liquid, pieces of 
filter-paper should be stirred in while still heating, till the residue is drj', 
avoiding an excess of paper. 

Cool, add 50 cc. of water, and remove the masses of char from the sides 
of the dish by the stirring-rod. Heat to boiling and filter. Use the 
filtrate for the Marsh apparatus, adding it gradually. 



592 



FOOD INSPECTION AND ANALYSIS. 



The arsenic mirror may be weighed in the usual manner, if of suffi- 
cient size. 

Reinsch's Test.* — Two hundred cc. of the beer are acidified with i cc. 
of pure, concentrated, arsenic-free hydrochloric acid, and evaporated to 
half its volume. 15 cc. more of hydrochloric acid are then added, and 
a piece of pure burnished copper foil half an inch long and a quarter of 
an inch wide is immersed in the liquid and kept in it for an hour while 
simmering, replacing from time to time the water lost by evaporation. If 
after the lapse of an hour the copper still remains bright, no arsenic is 
present. 

If the copper shows a deposit, remove, wash with water, alcohol, and 
ether, and dn,'. Then place the copper in a subliming-tube, and heat 
over a low flame. Tetrahcdral cn,'stals, apparent under the microscope, 
show the presence of arsenic. Blackening of the copper does not in itself 
prove arsenic. 

Malt Extract. — True malt extract is a syrupy fluid having a specitic 
gravity of from 1.3 to 1.6, and made up in accordance with the following 
directions of the 1880 Pharmacopoeia: Upon 100 parts of coarsely 
powdered malt contained in a suitable vessel, pour 100 parts of water, 
and macerate for six hours. Then add 400 parts of water, heated to 
about 30° C. and digest for an hour at a temperature not exceeding 55° C. 
Strain the mixture \vith strong pressure. Finally, by means of a water- 
bath or vacuum apparatus, at a temperature not exceeding 55° C, evapo- 
rate the strained liquid rapidly to the consistence of thick honey. 

Keep the product in well-closed vessels in a cool place. 

Such an extract has a residue of at least 70%, consisting chiefly of 
maltose, and contains about 2% of diastase. It should furthermore be 
capable of converting its own weight of starch at 55° C. in less than ten 
minutes. 

The following are analyses of three samples of pure malt extract: f 



ttj t 



1-387 
1. 421 
1.498 



X 



72.31 
76.65 
79.81 






0-275 
0.386 



S3 



0-033 3-329 
0.021 3. 1 16 
0-05314-872 



62.52 

65-41 
61.32 



5-25 
6.94 
12.39 



t-6 



1. 21 0.483 
1.190.556 
1.230.428 



Diastatic Action. 



Complete in less than s min. 
" " " 10 " 



* Jour. Soc. Chem. Ind., 20, p. 646. 

t Penn. Dept. of Agric. An. Rep., 1898, p. 85. 



ytLCOHOLIC BEyER/lGES. 



593 



There are on the market many so-called malt extracts widely advertised 
for their tonic and medicinal virtues, having the taste and consistency 
of beer or ale. In fact they are virtually beer, differing therefrom mainly 
in respect to price. Such "malt extracts" have no diastase, and their 
value as nutrients depends almost entirely on their sugar content. 

Harrington * has analyzed twenty-one of the best known of these 
alleged malt extracts, the maximum, minimum, and mean results of his 
analyses being as follows: 





Specific Alcohol. 
Gravity. 


Total 
Residue. 


Ash. 


Maximum 


i-°555 
1.0149 


7-13 
0.74 

3-94 


13-63 
S-I3 
8.78 


0-53 
0.20 











None of them contained any diastase, and several were preserved 
with salicylic acid. 

DISTILLED LIQUORS. 

These beverages differ from those hitherto considered, by reason of 
their high alcoholic content and low extract or residue. Indeed, when 
first distilled they are entirely without residue, but from long storage in 
casks, they absorb certain extractives from the wood, that impart more 
or less flavor as well as color. 

When any fermented alcoholic infusion is subjected to distillation 
under ordinary circumstances, a distillate results which consists of a 
mixture with water of a large number of alcohols, chief among which 
is ethyl alcohol. The high boiling alcohols — amyl, butyl, propyl, etc., 
with their esters — exist in the distillate in small amount, constituting 
what is known as fusel oil. The various distilled liquors of commerce 
are made by just such a process of distillation, the product varying widely 
in flavor and character with the basis from which it was distilled. 

By the processes involving the use of the so-called pot-still (the old- 
fashioned copper still and worm), it was impossible to obtain a pure con- 
centrated ethyl alcohol from fermented grain mash, the basis of whiskey, 
except by many repeated distillations. 

Now, however, by the use of improved apparatus, such as the Coffey 
still, involving the principle of fractional condensation, it is possible to 
obtain what is known as "silent spirit," or ethyl alcohol, free from 

* Boston Medical and Surgical Journal, Dec. 31, 1896. 



594 



FOOD INSPECTION AND ANALYSIS. 



fusel oil. With proper appurtenances for rectifying, one can now obtain 
95% alcohol by two distillations. 

Composition of Fusel Oil. — Fusel oil varies considerably in compo- 
sition with the source from which it is derived. Amyl alcohol, being 
in all cases its chief constituent, is frequently known commercially as 
fusel oil. The alcohols found in fusel oil with their formulas, specific 
gravity, and boiling-points are as follows: 



Ethyl alcohol 

Propyl " 

Butyl 

Amyl 

Hexyl " , 



Formula. 



QHsOH 
C3H7OH 
C,H5,OH 
C,H„OH 
C.H,30H 




The following acids have been found in fusel oil, usually combined 
with the alcohols to form compound ethers: 



Acetic HC.HjO^ 

Propionic HC3H5O2 

Butyric HC^H^O^ 

Valerianic HCsHaO, 



Caproic HCeH^O, 

(Enanthylic HC^HijO^ 

Caprylic HCgHijOj 

Pelargonic HC^HuO, 



Aging. — Freshly distilled liquors all contain notable quantities of 
fusel oil, which renders them harsh and unfit for use, but by the process 
of aging, the fusel oil becomes gradually transformed into the compound 
ethers that impart to the various liquors their distinctive bouquet, or flavor. 
Two or three years are usually required for the natural aging process. 



WHISKEY. 

Process of Manufacture. — Whiskey is the liquor resulting from the 
distillation of a fermented infusion of grain or potatoes. The fermented 
infusion known as the "mash" is obtained by steeping in water the 
starch-containing material, usually barley, rye, com, oats, or potatoes 
mixed with mah, and subjecting the mixture to the action of the diastase 
contained in the malt, in much the same manner as the mashing process 
in the brewing of beer, except that for whiskey the process of saccharous 
fermentation is carried further, with a view to obtaining a maximum 
yield of maltose and a minimum of dextrin. Yeast is afterwards added, 
and alcoholic fermentation allowed to proceed with proper precautions. 



ALCOHOLIC BEl^ERMGES. 595 

Rarely malt alone is used, but more often the grain most abundant 
in the locality where the whiskey is distilled forms the basis of the liquor. 
Bourbon whiskey (made originally in Bourbon County, Kentucky) is 
made from a mixture of grain, 50 to 60 per cent of which is com, 10% 
malt, and the balance rye. 

Corn alone mixed with malt is employed in some localities, and pure 
rye whiskey is made from rj'c and malt. Scotch and Irish whiskey is 
commonly made from a mixture of oats, barley, rye, and malt. 

Potatoes sometimes form the basis of the mash, the starch being con- 
verted to sugar either by mixture of the pulped potato with malt, or by 
boiling with dilute sulphuric acid and afterwards neutralizing, as in the 
manufacture of commercial glucose. 

The fermented wort obtained from either source is subjected to dis- 
tillation, without any attcm])t to rectify or separate out the fusel oil. The 
product of the first distillation is called "low wines" and is redistilled; 
the product of the second distillation is commonly divided into three 
fractions, of which the middle portion, or "clean spirit," is retained for 
the whiskey, while the first ("foreshots") and the last fraction (faints) 
are mixed with the next portion of low wine to be redistilled. If the 
whiskey is too high in alcohol, it is diluted to the proper strength. While 
the last fraction on redistillation is highest in fusel oil, notable quan- 
tities of the latter are present in the new whiskey, giving it a crude, harsh 
taste. It is therefore subjected to "aging," or storing in casks, preferably 
for a number of years. This aging process softens and refines the flavor, 
due to the transformation of the fusel oil into compound ethers. When 
first distilled whiskey is perfectly colorless, but during the aging it extracts 
more or less color and some flavor from the oak casks in which it is stored. 
Its flavor varies considerably with the nature of the grain used in its prepa- 
ration. Malt dried over burning turf or peat (as used in the manufacture 
of Irish whiskey) acquires a not unpleasant smoky taste, which it imparts 
to the finished product. 

Composition. — Whiskey consists chiefly of alcohol and water, with 
the flavor due to its fusel oil derivatives. Its extract, derived mainly 
from the wine-cask in which it is stored, should consist only of traces of 
tannin, sugar, and coloring matter. It has a very small amount of 
volatile oil, rarely exceeding 0.1%. 

Thirty-seven samples of whiskey, purchased by the glass from various 
Massachusetts saloons, were examined by the Massachusetts State Board 
of Health in 1894, with the following results: 



596 



FOOD INSPECTION AND ANALYSIS. 





Per Cent 

Alcohol by 

Weight. 


Per Cent 
Extract. 




45-96 
30.70 

36-51 


1.68 
0.08 
0.50 




Mean 





Seven of these samples had an excess of tannic acid, three had no 
tannic acid at all, two or three had insoluble residues, and one showed 
notable traces of fusel oil. 

Adulteration of Whiskey and Standards of Purity. — The U. S. Pharma- 
copoeia fixes the following requirements for whiskey: It should be at 
least two years old; in specific gravity it should lie between the limits 
of 0.930 and 0.970; its alcoholic content should be not less than 44% nor 
more than 50% by weight;- its residue should be not more than 0.25%; 
the residue from 100 cc, which should be neither sweet nor spicy, should 
dissolve in 10 cc. of cold water, and this solution should be colored only 
a pale green when treated with a drop of very dilute ferric chloride solu- 
tion (a deeper color would indicate more than traces of tannin). In 
evaporating the liquor on the water-bath for the residue, the last traces 
volatilized should have an agreeable odor free from harshness, indicative 
of the absence of fusel oil. Its reaction should be slightly acid, but not 
more than 1.2 cc. of tenth-normal alkali should be required to neutralize 
100 cc. of the liquor, using phenolphthalein as an indicator. 

The standards suggested for adoption to the A. O. A. C. by its Com- 
mittee on Standards are as follows : Alcohol not less than 44% by volume 
nor more than 55% ; solid matter not more than 0.25%. 

Artificial Whiskey. — Whiskey is often artificially concocted by dilut- 
ing strong alcohol or silent spirit to the proper strength, coloring with 
caramel, sometimes adding for body prune juice, and adding for flavor 
certain essential oils, such as oil of wintergreen, and artificial fruit essences, 
such as oenanthic and pelargonic ethers. As a rule a small amount of 
pure whiskey is mixed with the artificial to give it flavor. 

Among Fleischman's recipes for "blended" whiskey is the following, 
which he claims to be the very lowest grade: 

Spirits 32 gallons 

Water 16 " 

Caramel 4 ounces 

Beading oil i ounce 



ALCOHOLIC BEyERMGES. 



597 



"Beading oil" is prepared by mixing 48 ounces oil of sweet almonds 
with 12 ounces C. P. sulphuric acid, neutralizing with ammonia, adding 
double the volume of proof spirits, and distilling. This preparation is 
so called because it is largely used for putting an artificial bead on cheap 
liquors. 

A little creosote is sometimes added to give a burnt taste in sem- 
blance of Irish whiskey. Pungent materials such as cayenne pepper 
are said to be used as adulterants, but no record is known of any substance 
being used more injurious than the alcohols. Sugar is a frequent adul- 
terant. 

Some doubt e.xists as to the injurious effects of fusel oil on the system. 

BRANDY, OR COGNAC. 

Brandy is the product of the distillation of fermented grape juice or 
wine. In a broader sense the term brandy is sometimes applied to liquor 
distilled from the juices of other fruits, such as apples, peaches, cherries, 
etc. The finest grades of brandy, such as pure cognac and armagnac 
(named from towns in France in which they were originally distilled), 
are made from choice white wine by the use of pot stills, and naturally 
command a high price. Brandy of a lower grade is distilled from the 
cheaper wines, and sometimes from the fermented marc, or refuse, of the 
grape, as well as from the lees and "scrapings" of the casks. The best 
brandies are sometimes rectified by a second distillation. Like whiskey, 
the fresh brandy is colorless, and would so remain if stored in glass or 
stone. The color is due to the wooden casks in which it is stored. Brandy 
consists of nearly pure alcohol and water, having a characteristic flavor, 
differing somewhat according to the nature and quality of the wine from 
which it was prepared. The chief flavor of pure cognac is due to cenan- 
thic ether. 

Thirty-seven samples of brandy, collected from Massachusetts bar- 
rooms in 1894 and examined by the State Board of Heakh, showed the 
following results: 





Per Cent 

Alcohol by 

Weight. 


Per Cent 
Extract. 




50.70 
21.30 
40.54 


3.00 

O.IO 

°-9i 




Meaa 





598 FOOD INSPECTION /tND /iN/t LYSIS. 

Three of these samples were artificially prepared mixtures of alcohol 
and water, one showed the presence of cloves, five contained tannin in 
excess, nine were excessively acid, two contained fusel oil, and two had 
insoluble residues. 

Adulteration and Standards of Purity. — According to the U. S. Phar- 
macopoeia, brandy should be at least four years old; its specific gravity 
should be not more than 0.941 nor less than 0.925; its alcoholic con- 
tent should be from 39 to 47 per cent by weight; its residue should not 
exceed 1.5%; the residue from 100 cc. should dissolve readily in 10 cc. 
of cold water, and this solution should not be colored deeper than a pale 
green by the addition of dilute ferric chloride solution (absence of more 
than traces of tannin) ; the residue should not be sweet nor spicy in taste ; 
a marked disagreeable pungent odor of fusel oil should not manifest 
itself on the volatilization of the last traces of alcohol in evaporating 
for the residue; in acidity, not more than i cc. of tenth-normal alkah 
should be required to neutralize 100 cc. of the brandy, using phenol- 
phthalein as an indicator. 

The suggested standards for the A. O. A. C. place the limits of alcohol 
between 44 and 55 per cent by volume, and the solid matter not to exceed 

0.35%- 

Much of the brandy sold on the market is of the "improved," or 

"blended," variety, having for its basis alcohol reduced to the requisite 

strength, flavored either by the admix-ture of real brandy, or by various 

preparations such, for example, as syrup of raisins, prune juice, rum, 

acetic ether, oenanthic ether, infusion of green walnut-hulls, infusion of 

bitter almond shells, catechu, balsam of Tolu, etc. 

Fleischman gives the following recipe for artificial brandy of the 

cheapest grade: 

Spirits 45 gallons 

Coloring (caramel) 6 ounces 

Cognac oil \ ounce 

"Cognac oil" is made up of melted cocoanut oil 16 ounces, sulphuric 
acid 8' ounces, alcohol 16 ounces, mixed and distilled. 

WTiile commercial brandy often fails to meet the pharmacopoeial 
requirements, and may contain any of the above flavoring materials, 
not one sample has been found among the many examined by the Massa- 
chusetts Board of Health during upwards of twenty years containing a 
more injurious ingredient than alcohol. 



ALCOHOLIC BEVERAGES. 599 

Genuine new brandy may be "aged" or "improved" for immediate 
use, according to Duplais, by adding to loo liters the following: 

Old rum 2 . oo liters 

Old kirsch* 1.75 " 

Infusion of walnut-hulls 75 liter 

Syrup of raisins 2 .00 liters 

The addition of sugar and caramel to brandy is very common. The 
lack of flavor resulting from the employment of "silent spirit," or from 
watering the product, may be compensated for by the employment of 
so-called cognac essences sold for the purpose, containing mixtures of 
the aromatic compounds named above. 



RUM. 

Rum is the liquor distilled from fermented molasses or cane juice, 
or from the scum and other waste juices from the manufacture of raw 
sugar. The molasses wort is mixed with the residue from a previous 
fermentation and allowed to ferment for a number of days, after which 
it is distilled twice and stored in wood for a long time, to remove the dis- 
agreeable odor, which in the new product is especially marked. The 
characteristic flavor of old rum is due to a mixture of butyric and acetic 
ether, principally the former. Pineapples and guavas are often put 
in the still to impart a fruity flavor. The best varieties of rum come 
from Jamaica and Vera Cruz. 

Thirty-nine samples of rum, sold at retail in Massachusetts in 1894, 
were examined by the State Board of Health with the following results: 





Per Cent 

Alcohol by 

Weight. 


Per Cent 
Extract. 




42.9 
24-7 
37-1 


3-93 
0.04 

°-5i 


Minimum. . . 


Mean 





Of these, two samples were new rum, and several were entirely arti- 
ficial. 

The suggested standard for rum of the A. O. A. C. sets the alcoholic 
content between 44 and 55 per cent by volume. More or less factitious 
rum is sold on the market, made up of alcohol diluted to the right strength, 
* Brandy distilled from cherry wine. 



6oo FOOD INSPECTION ziND /tN A LYSIS. 

colored with caramel, and flavored by the addition of "rum essence." 
Prune juice is sometimes added. 

Fleischman gives the following recipe for low-grade artificial rum: 

Spirits 40 gallons 

New England rum 5 " 

Pnme juice ^ gallon 

Caramel 12 ounces 

Rum essence 8 " 

The "rum essence" is made up by distilling 32 ounces of a mixture 
of 2 ounces black oxide of manganese, 4 ounces pyroligneous acid, 32 
ounces alcohol, and 4 ounces sulphuric acid. To this is added 32 ounces 
of acetic ether, 8 ounces of butyric ether, 16 ounces saffron extract, and 
i ounce oil of birch. 

GIN. 

Gin is an alcoholic liquor, flavored with the volatile oil of juniper and 
sometimes with other aromatic substances, such as coriander, grains of 
paradise, anise, cardamom, orange-peel, and fennel. The choicest variety 
5s known as Schiedam schnapps, named from the town of Schiedam in 
Holland, where there are upwards of 200 distilleries devoted to the manu- 
facture of gin. The mash used for this variety is fermented by yeast 
from malted barley and rye, after which it is distilled and redistilled 
in pot stills with juniper berries and sometimes hops. 

Jimiper berries, to which the most characteristic flavor of gin is due, 
are dark blue in color, and possess a pungent taste. They grow on the 
slender evergreen shrub Juniperus communis. Gin differs from the 
other distilled liquors by being water-white. To this end it is kept in 
glass and not in wood. 

Much of the gin of commerce is made by redistilling com or grain 
whiskey with oil of juniper, and frequently one or several of the above- 
named flavoring materials. Sugar is often added, and sometimes in the 
cheaper productions oil of turpentine is substituted for juniper oil. 

Thirty- three samples of gin, purchased in Massachusetts saloons and 
analyzed by the State Board of Health in 1894, gave the following results 
in per cent of alcohol by weight: Maximum 42.5, minimum 29.5, mean 
38.2. 

The standard for gin suggested for adoption by the A. O. A. C. pre- 
scribes its alcoholic strength as not less than 40% by volume. 



ALCOHOLIC BEyERAGES. 60 1 

Methods of Analysis of Distilled Liquors. — Alcohol and Extract 
are determined as directed on pages 528 and 547. Acidity is determined 
by titrating directly a measured volume of liquor, say 100 cc, with 
tenth-normal alkali, using phenolphthalein for an indicator and calcu- 
lating results as acetic acid, 0.006 gram of which is the equivalent of i cc. 
of the standard alkali. 

Detection of Fusel Oil. — In the process of dealcoholizing a liquor by 
evaporation in an open dish over the water-bath, one may readily detect 
fusel oil, if present, by its harsh and nauseating odor, if the nose is applied 
just at the moment when the last traces of alcohol are going off. At 
this stage any considerable trace of fusel oil will be especially apparent 
by the effect on the throat of the one who smells it, causing an uncon- 
trollable desire to cough. Other ways of applying the odor test consist 
in pouring a small portion of the spirit into the hand, and allowing it to 
evaporate slowly therefrom, or in rinsing out a warm glass with the liquor, 
observing the odor in each case. 

Goebel suggests the following test, based on the detection of the 
volatile acids: Agitate about 30 cc. of the liquor with 2 or 3 cc. of 
a dilute solution of potassium hydroxide; evaporate over the water- 
bath to the volume of 2 or 3 cc, cool, and to the residue add 5 or 6 cc. 
of concentrated sulphuric acid. If fusel oil be present, the character- 
istic odors of valerianic and butyric acids will be apparent. 

Determination of Fusel Oil. — The Rose-Stutzer-W indisch Method* — 
The apparatus recommended for this determination is Bromwell's modi- 
fication of Rose's fusel oil apparatus. 

This apparatus consists of a pear-shaped bulb holding about 200 cc, 
stoppered at the upper end and sealed at the lower to a graduated stem 
about 4 mm. in internal diameter. To the lower end of this graduated 
stem is a sealed bulb of 20 cc. capacity, the lower end of which bears a 
stop-cock tube. The apparatus is graduated to 0.02 cc. from 20 cc. to 
22.5 cc. 

The reagents required are fusel-free alcohol, that has been prepared 
by fractional distillation over caustic soda or caustic potash and diluted 
to exactly 30% by volume (specific gravity 0.96541), chloroform freed 
from water and redistilled, and sulphuric acid (specific gravity 1.2857 
at 15.6°). 

Distill slowly 200 cc. of the sample under examination (having first 

* Arbeit, d. kaiserl. Gesund., i88g, 5, 391. Zeits. f. anal. Chem., 34 (1895), AmtL 
Verordn. u. Erl. S. 2. U. S. Dept. of Agric, Bur. of Chem., Bui. 46, p. 69. 



6o2 



FOOD INSPECT/ON AND ANALYSIS. 




made alkaline) till about 175 cc. have passed over, allow the distilling- 
flask to cool, add 25 cc. of water, and distill again till the total distillate 
measures 200 cc. Dilute the distillate to exactly 30% by 
volume (specific gravity 0.96541 at 15.6°). 

Prepare a water-bath the contents of which are kept 
at exactly 15°, and place in it the apparatus (covering 
the end of the tube with a rubber cap to prevent wetting 
the inside of the tube) and flasks containing the 30% 
fusel-free alcohol, chloroform, sulphuric acid, and the 
distillate diluted to 30% by volume. When the solu- 
tions have all attained the temperature of 15°, fill the 
apparatus to the 20-cc. mark with the chloroform, draw- 
ing it through the lower tube by means of suction, add 
100 cc. of the 30% fusel-free alcohol and i cc. of the 
sulphuric acid, invert the apparatus and shake vigorously 
for two or three minutes, interrupting once or twice to 
open the stop-cock for the purpose of equalizing pressure. 
Allow the apparatus to stand ten or fifteen minutes in 
water that is kept at the temperature of 15°, turning 
occasionally to hasten the separation of the reagents, and 
note the volume of the chloroform. After thoroughly 
cleansing and drying the apparatus, repeat this operation, 
using the diluted distillate from the sample under ex- 
amination in place of the fusel-free alcohol. The increase 
in the chloroform volume with the sample under exami- 
nation over that with the fusel-free alcohol is due to 
fusel oil, and this difference (expressed in cubic centi- 
meters) multiplied by the factor 0.663 g'^es the volume 

Fig. 115. — Brom- ' ^ .... T , 

well's Fusel Oil of fusel oil in 100 cc, which is equal to the percentage 
Apparatus. of fusel oil by volume in the 30% distillate. This must 
be calculated to the percentage of fusel oil by volume in the original 
liquor. 

Example. — A sample of liquor contains 50% of alcohol by volume. 
The increase in the chloroform volume with the 30% fusel-free alcohol 
is 1.42 cc; the increase in the chloroform volume with the distillate from 
the liquor under examination, diluted to 30%, is 1.62 cc; difference, 
0.20 cc. The volume of fusel oil in 100 cc. of the 30% distillate then 
is 0.20X0.663 = 0.1326 cc, and by the proportion 30:50: :o.i326:o.22i 
we obtain the percentage of fusel oil by volume in the original liquor. 



/ILCOHOLIC BEl^ER/IGES. 603 

Determination of Ethereal Salts. — Provisional Method oj the 
A. O. A. C. — Neutralize the residue left after distillation in the fusel oil 
determination with N/io HjSO^, and add an excess of 10 cc. of the acid. 
Let stand 5 minutes and make up to 200 cc. Titrate 2 portions of 25 cc. 
each, using as indicators methyl orange in the first and phenolphthalein 
in the second. The difference gives the amount of alkah necessary' to 
neutrahze the organic acids in 25 cc. of the sample. By subtracting from 
this figure the number of cubic centimeters of alkali required for the 
free acids, and multiplying the result by 0.0088, the number of grams of 
ethereal salts (calculated as ethyl acetate) in 25 cc. of the sample is de- 
termined. 

Furfurol in Distilled Liquors and its Determination. — Furfurol is 
found in liquors distilled from starchy materials in pot stills, or those 
heated by direct contact with the fire, but not in liquors produced by 
indirect or steam boiling. Hence the furfurol is believed to be due to 
the charring of these starchy ingredients. 

McGill * describes the following colorimetric test : Fifty cc. of the 
liquor to be tested are measured into a Nessler tube, and i cc. of anilin 
reagent f is added. In the presence of furfurol a reddish color is pro- 
duced, dependent in depth on the amount present, but readily observable 
■with 0.001%. Results are reported as distinct, faint, or none, though 
approximate quantitative results are possible, if the color is matched 
against a known-strength solution of furfurol similarly treated. 

Detection of Caramel. — Crampton and Simons^ Methods. — (a) With 
Fullers' Earth.% — Mix by vigorous shaking in a corked flask 50 cc. of the 
liquor with 25 grams of fullers' earth, let stand for half an hour, and filter. 
A naturally colored liquor will show little change in color in the filtrate, 
while a liquor colored with caramel will be largely decolorized, or at least 
deprived of such of the color as is due to caramel. By comparing ia 
test-tubes the relative lengths of column of the filtrate, and the original 
liquor diluted with water to match the tint of the filtrate when viewed frora . 
above, one can approximately estimate the amount of caramel used. 

All varieties of fullers' earth do not possess the property of absorbing 

* Bui. 27 Canada Inland Rev. Dept. 

t The reagent used is made up as follows : 

Redistilled anilin i volume 

Glacial acetic acid i 

Distilled water 2 volumes 

X Jour. Am. Chem. Soc, 21 (1899), p. 355. 



6o4 



FOOD INSPECTION ^ND /tN A LYSIS. 




caramel in equal degree. When a satisfactory variety is obtained, it 
is well to procure a large amount for reagent purposes. 

(6) With Ether.* — Evaporate 50 cc. of the liquor nearly but not quite 
to dryness on the water-bach. Wash with water into a 50-cc. graduated 
glass-stoppered flask, add 25 cc. of absolute alcohol, and fill to the mark 
with water. Shake, and transfer 25 cc. of the solution 
to a separatory funnel of the type represented in Fig. 
116, the stem of which terminates in a 25-cc. graduated 
bulb pipette, provided with a stop-cock as shown. 

Add 50 cc. of ether, and shake carefully at intervals 
during half an hour. After complete separation, make 
up the lower aqueous layer with water to the 25-cc. 
mark, which may be done by siphoning it in through a 
rubber tube from an elevated flask, controlling the sup- 
ply by the stop-cock. Shake the separatory funnel, and 
again allow the layers to separate, draw off the aqueous 
layer, and compare with the color of the original liquor. 
Ether will readily dissolve the natural color due to oak- 
wood (mainly flavescin), while caramel is insoluble in 
ether. Hence ether acts in a reverse manner to the 
fullers' earth, partially decolorizing naturally colored 
liquor, and showing little change of color with samples 
treated with caramel. Less variation in color between 
Fro. 116.— Separa- the original and final solution is shown by the ether 
ton- Funnel for treatment than by that with fullers' earth, though, ac- 
Detection of wording to Crampton and Simons, the two methods are 

Caramel. 

always conhrmatory. 
Opalescence in Diluted Alcohol Distillate. — McGill f has shown that 
in the case of liquors made from thoroughly rectified grain spirit, there 
is little or no opalescence produced when the alcoholic distillate (i.e. 
that used in determining the alcohol) is diluted with an equal volume 
of water, while in the case of liquors distilled from alcoholic infusions 
without rectification, the opalescence is marked. He ascribes the opales- 
cence to the presence of minute amounts of volatile oils present in wine 
marc, grains, and other sources of these liquors, soluble in strong but 
insoluble in dilute alcohol. Whether due to this or to the separation 
of minute traces of fusel oil on dilution, the presence or absence of tur- 

* Jour. Am. Chem. Soc, 22 (igco), p. 810. 
t Bui. 27 Canadian Inland Rev. Dept. 



/ILCOHOLIC BEI/ERAGES. 605 

bidity certainly furnishes a rough distinguishing test, indicating in some 
cases the exclusive use of rectified spirit. 



LIQUEURS AND CORDIALS. 

These are manufactured beverages, usually high in alcohol and sugar, 
flavored with a wide variety of aromatic herbs or essences, and often 
strongly colored. Red colors most frequently used for this purpose 
are cochineal, cudbear, and red sandal and Brazil woods; for yellow 
colors, caramel and sa£fron-yellow are employed; for blue, indigo; and 
for green, chlorophyll and malachite green. 

Some of the oldest of the liqueurs, such as chartreuse and bfoedictine, 
derive their names from certain monasteries of Europe, in which they 
have been made for many years. 

Absinthe is one of the best-known cordials, made by redistilling 40% 
alcohol in which wormwood, anise, sweet flag, and marjoram leaves 
have been macerated. Sometimes coriander and fennel are also used. 
It is highly intoxicating. 

Curagoa is made by distilling dilute spirits in which Curajoa orange- 
peel,* cinnamon and often other spices have been soaked, and by adding 
sugar to the resulting liqueur. 

De Brevans gives the following recipe for curafoa: 

Rasped skins of 18 or 20 oranges 

Cinnamon 4 grams 

Mace 2 " 

Alcohol (85%) 5 liters 

White sugar 1750 grams 

Macerate for fourteen days, distill without rectification, and color with 
caramel. 

Angostura owes its flavor to Angostura bark and various spices. 

Maraschino had originally for its basis the fermented juice of the 
sour Italian cherry, to which honey was added. It is more commonly 
made by distilling a mixture in alcohol of ripe wild cherries, raspbenies, 
cherry leaves, peach nuts, and orris. Finally sugar is added. 

Chartreuse ayid Benedictine contain much sugar, and are flavored 
with the volatile oils of angelica, hyssop, nutmeg, and peppermint. 

Noyau, or Crime de Noyau, is a preparation distilled from brandy, 

* This is a very rare and highly prized orange, growing in the island of Curajoa. 



6o6 



FOOD INSPECTION AND ANALYSIS. 



bitter almonds, mace, and nutmeg. Sugar and coloring matter, usually 
pink, are added to the final product. 

Creme de Menthe, according to De Brevans, is made by distilling a 
mi.xture of 

Peppermint 600 grams 

Balm 40 " 

Sage ID " 

Cinnamon 20 " 

Orris root 10 " 

Ginger 15 

Alcohol (80%) 5030 cc. 

producing finally 10 liters of the liquor, after 3750 grams of white sugar 
have been introduced. 

The green color of creme de menthe is almost entirely artificial. The 
better grades are colored with an alcoholic solution of clilorophyll, derived 
by macerating bruised green leaves of various plants with alcohol for 
several days. Coal-tar dyes arc used in the cheaper grades. 

The following analyses, due to Konig, show the chemical composition 
of the best-known cordials: 



Specific 
Gravity. 



Alcohol 
by Vol- 
ume. 



Alcohol 

by 
Weight. 



Extract. 



Cane 
Svigar. 



Other 
Extrac- 
tives. 



Absinthe 

Benedictine 

Ginger 

Creme de menthe. . - . 
Anisette de Bordeaux. 

Curafoa 

Kiimmel 

Angostura 

Chartreuse 



0.9116 
1.0709 
1. 048 1 
1.0447 
1.0847 
I . 0300 
1.0830 
0-9540 
1-0799 



58.93 
52 



47 
48 
42 

55 

49 
43- 



38.5 
36.0 

36.5 
30-7 
42-5 
24.8 



0.18 
36.00 

27.79 
28.28 
34.82 
28.60 
32.02 

S-85 
36.11 



32.57 
25.92 
27.63 
37-44 
28.50 
31.18 
4.16 
34-35 



0.32 

3-43 
1.87 
0.65 
0.38 
o. 10 
0.84 
1 .6g 
1.76 



0.043 
0.141 
0.068 
0.040 
0.040 
0.058 



Analysis of Cordials and Liqueurs. — The character of the essences 
and flavoring principles used in these beverages is so widely varied that 
no regular systematic plan for identifying them can be made applicable 
to all cases. The senses of smell and taste are most useful, both when 
applied directly to the liqueur itself and to the drj' extract, for suggestions 
as to the main ingredients employed. Coloring-matters, sugars, acids, 
and alcohol are determined as with other liquors, except that in the case 
of alcohol all volatile oils must first be separated out by treatment with 
magnesia, as directed for alcohol in lemon extract. Presence of volatile 



MLCOHOUC BEyERAGES. 607 

oils is shown, if on treatment of a few cubic centimeters of the sample 
in a test-tube with water a precipitate is formed. 

GENERAL REFERENCES ON ALCOHOLIC BEVERAGES. 
(See also References on Leavening Materials, page 275.) 

Bersch, J. Gahrungs-Chemie fur Praktiker. Berlin. Vol. I, Die Hcfe und die Gahr- 

ungs Erscheinungen, 1879. Vol. II, Fabrikation von Malz, Malz Extract und 

De.xtrin, i88o. Vol. Ill, Die Bierbrauerei, 188 1. 
BiGELOw, W. D. Fermented and Distilled Liquors. U. S. Dept. of Agric, Bur. of 

Chem., Bui. 65, p. 81. 1902. 
BouRGUELOT, E. Des Fermentations. Paris, 1889. 

Brevans, J. DE. The Manufacture of Liquors and Preserves. New York, 1893. 
Cra\epton, C. a. Fermented Alcoholic Beverages. U. S. Dept. of Agric, Div. of 

Chem., Bui. 13, part 3. 1887. 
DuPLAis, P. (Translated by McKennie, M.) A Treatise on the Manufacture and 

Distillation of Alcoholic Liquors. Philadelphia. 
Fleischman, J. The Art of Blending and Compounding Liquors and Wines. New 

York, 1885. 
GiRARD, C. La Fabrication des Liqueurs et des Conserves. Paris, 1890. 
Hansen, E. Ch. Untersuchungen aus der Pra.xis der GahrungsTndustrie. Miinchen, 

1889. 
Mew, J., and Ashton, J. Drinks of the World. London, 1892. 
Pasteur, M. Studies in Fermentation. London, 1879. 

Prescott, a. B. Critical E.xamination of Alcoholic Liquors. New York, 1880. 
Spencer, E. The Flowing Bowl. A Treatise on Drinks of all Kinds and of all Periods. 

London, 1899. 
Stevenson, T. A Treatise on Alcohol with Tables of Spirit Gravities. London, 1888. 
A Treatise on the Manufacture, Imitation, Adulteration and Reduction of Foreign 

Wines, Brandies, Rums and Gins, based upon the "French System," by a 

Practical Chemist and Experienced Liquor Dealer. 

REFERENCES ON BEER. 

Allen, A. H., and Chattaway, W. Detection of Hop Substitutes in Beer. Analyst, 

12, 1887, p. 107; also .\nalyst 15, 1890, p. 181. 
Brevans, J. de. Analyse des Matieres Alimentaires (Girard et Dupre), p. 183. Paris, 

1894. 
Elion, H. Detection of Antiseptics in Beer. Analyst, 16, 1891, p. 116. 
Faulkner, F. Theory and Practice of Modern Brewing. London, 1888. 
Hefelmann, R., and Mann, P. Detection of Fluorine in Beer. Pharm. Centralh., 

1895, 16, 249; Abs. Analyst, 20, 185. 
Kelynack, T. N., and Kirby, W. Arsenical Poisoning in Beer Drinkers. London, 

1901. 
Lindet, L. La Biere. Paris, 1892. 

Lindner, C. Lehrbuch der Bierbrauerei. Braunsweig, 1878. 
Macfarlane, T. Malt Liquors. Canada Inl. Rev. Dept. Bui. 52. 



6o8 FOOD INSPECTION AND ANALYSIS. 

Pasteur, M. Etudes sur la Biere. Paris, 1876. 

PiESSE, C. H. Chemistry in the Brewing Room. London, i8gi. 

Prior, E. Chemie und Physiologie des Maizes und des Bieres. Leipzig, 1896. 

Stierlein, R. Das Biere und seine Verfalschungen. Berlin, 1878. 

REFERENCES ON CIDER AND WINE. 

Alwood, W. B. a Study of Cider Making. U. S. Dept. of Agric, Bur. of Chem., 

Bui. 71. 
Bartllot, E. Manuel de I'Analyse des Vins. Paris, 1889. 
Barth, M. Die Weinanalyse. Leipzig, 1884. 
Bastide, E. Les Vins Sophistiques. Paris, 1889. 
Browne, C. A. The Chemical Analysis of the Apple, and some of Its Products. Jour. 

Am. Chem. Soc, 23, 1901, p. 86g. 
BORGUANN, E. Anleitung zur chemischen Analyse des Weines. Wiesbaden, 1898. 
Cazeneuve, p. La Coloration des Vins par les Couleurs de la Houille. Paris, 1886. 
Embrey, G. a Comparison of English and American Cider, with Suggestions for 

Estimating the Amount of Added Water. Analyst, 16, 1891, 41. 
Gauteer, a. La Sophistication des Vins. Paris, 1884. 
Macfarlane, T. Wines. Canada Inl. Rev. Dept. Bui. 38. 

Nessler, J. Die Bereitung, Pflege und Untersuchung des Weins. Stuttgart, 1889. 
NrviERE, G., and Hubert, A. Detection of Fluorine in Wine. Monit. Sclent., 1895, 

9, p. 324; Abs. Analyst, 20, 185. 
Pasteur, M. Etudes sur le Vin. Paris, 1873. 

Robinet, E. Manuel Pratique d'Analyse des Vins. Paris, 1888. 
Sangle-Ferriere. Vin. Analyse des Matiferes Alimentaires (Girard et Dupr6), 
p. 63. Paris, 1894. 

Cidre. Loc. cit., p. 217. 

Viard, E. Traits general des Vins et de leurs Falsifications. Paris, 1884. 

REFERENCES ON DISTILLED LIQUORS. 

Allen, A. H. The Chemistry of Whiskey and Allied Products. Jour. Soc. Chem. Ind., 

10, 1891, p. 312. 

Brannt, W. T. Practical Treatise on the Distillation of Alcohol. Phila., 1885. 

Gaber, a. Die Fabrikation von Rum, Arrak, Cognac, etc. Leipzig, 1886. 

Macfarlake, T., and McGill, A. Distilled Liquors. Canada Inl. Rev. Dept. Bui. 27. 

Mouzert. The Practical Distiller. 1890. 

Richter, H. Analyse des Rums. Zeits. landw. Gerwerbe, 1889, 9, 11. 

Sanglier, a. Alcohols et Spiritueux. Analyse des Matieres Alimentaires (Girard et 
Dupre), p. 253. Paris, 1894. 

Scala, a. Rum and Its Adulteration. Gazetta Chem. Ital., 1891, 396; Abs. Ana- 
lyst, 17, 1892, 79. 

Sell, E. Ueber Cognac, Rum, Arrak, etc. Berlin, 1890. 



CHAPTER XV. 

VINEGAR. 

Vinegar is the product formed by the acetic fermentation of an alco- 
holic liquid under the influence of the organism mycodernia aceti, existing 
in the "mother-of-vinegar. " While vinegar may be made directly from 
a dilute solution of pure alcohol, it is more often obtained from fruit juice, 
wine, or other saccharine liquid that has first undergone alcoholic fer- 
mentation. 

Of the following equations, (i) and (2) illustrate the processes of 
inversion and alcoholic fermentation respectively, while (3) and (4) show 
the double process of acetic fermentation, wherein the alcohol is oxidized, 
first to acetaldehyde and finally to acetic acid: 

Q,H,,0,,-fH,0 = 2QH,20o; (I) 

Cane sugar Invert sugar 

QH,,Oe = 2C,H«0+2C02; (2) 

Invert sugar, Alcohol 
dextrose, or 
maltose 

C3H«0 + = CH,0 + H,0; (3) 

Alcohol Aldehyde 

c,n,o+o=c^Yi.,o,. . c (4) 

Aldehyde Acetic acid 

In addition to the acetic acid, its chief active principle, vinegar usually 
contains traces of other organic acids free or combined, small amounts 
of alcohol, aldehyde, sugar, glycerin, coloring matter, aromatic ethers, 
and mineral salts, its extract varying considerably with the source from 
which the vinegar was obtained. 

Varieties. — The principal varieties of vinegar are the following : Cider 

vinegar, wine vinegar, malt or beer vinegar, spirit vinegar, glucose vinegar, 

molasses vinegar, and wood vinegar, the three last being more frequently 

used as adulterants of the others. 

609 



6io FOOD INSPECTION AND ANALYSIS. 

Manufactnre of Vinegar. — Cider vinegar, the principal variety used in 
the United States and Canada, was formerly made almost entirely by the 
slow process of cask fermentation, the fresh cider being allowed to undergo 
both alcoholic and acetic fermentation in barrels with open bung-holes in 
a warm cellar, or exposed to the sun. Two or three years are required 
for this process. Sometimes fresh cider is added to the barrels at regular 
intervals of two or three weeks, thus causing a series of progressive fer- 
mentations. The acetic fermentation is hastened by adding old vinegar, 
or mother-of-vinegar to the cider. While farmers and some manufac- 
turers still continue to make cider vinegar by the slow process, the cjuick 
or "generator" vinegar process is now much used for cider vinegar, 
though originally intended and almost exclusively used in the manufacture 
of malt, beer, and spirit vinegar. This process requires only two or 
three days for complete acetification. In the quick process, the cider 
or other alcoholic liquor is allowed to percolate slowly through beech- 
wood shavings or birch twigs, held in a cask known as a generator, 
provided with a perforated, false bottom, the shavings or twigs being 
previously saturated with old vinegar, and a current of air being passed 
up through them. 

The alcoholic liquid from which genuine malt vinegar is made is 
derived from the wort obtained by mashing malt, or a mixture of malt 
and barley. Spirit vinegar is derived from diluted whiskey, brandy, or 
grain alcohol. Wine vinegar is made by allowing the wine to stand over 
wine lees for a time, after which it is clarified by passing through beech 
shavings, and subjected to progressive acetification in large open oak 
casks, to which the wine is added, the vinegar being drawn off in much 
the same manner as the slow-process cider vinegar. 

Characteristics and Composition of the Various Vinegars. 
— Cider Vinegar is brownish yellow in color, and possesses an odor of 
apples. It is chiefly distinguished from other vinegar by the large amount 
of malic acid normally present, by the character of its sugars, and by the 
predominance of potash in the ash. Its specific gravity varies from 
1.013 to 1.015. Its acidity varies from 3 to 6 per cent, and its solids 
from li to 3 per cent. Cider vinegar under polarized light is always 
Iffivo-rotary. 

The following are summarized data of analyses made by H. C. Lyth- 
goe in the writer's laboratory of twenty-two samples of cider vinegar of 
known purity: 



yiNEG/IR 



6ii 





Acetic 
Acid. 


Total 
Solids. 


Ash. 


AlkaUn- 
ity of 
Ash.i 


Papsin Ash of 100 
Grams Vinegar. . 




Soluble 
Cmgr.). 


Insoluble 
(mgr.). 


Maximum .... 


5.86 

3-92 
4.84 


3.20 
1.84 
2.49 


0.42 
0.20 
0.34 


36.1 

22.2 
29.7 


31-7 
12. 1 
19.2 


6-S 
15-6 




Average 





Reducing Sugars. 


Polariza- 
tion, 
Degrees 
Ventzke 
200-mm. 
Tube. 


Malic 
Acid. 


Per Cent 
Ash in 
Total 
SoUds. 


Per Cent 
Reducing 

Sugars 
in Total 

Solids. 


Ratio of 

Soluble 

to Total 

P-O5. 


AlkaUn- 




Before 
Inversion. 


After 
Inversion. 


1 Gram of 

Ash, cc. 

^ Acid. 

10 


Maximum 

Minimum. . . . 
Average 


°-5I 
0.15 
0.25 


0-53 
0-15 
°-25 


-3-6 
-0-3 
-1-3 


0, t6 
0.08 

O.II 


19.0 
10. 
13.8 


16.6 

7-3 
10.7 


66.9 
50.0 
56.3 


125.0 
69.0 
90.0 



' Number of cubic centimeters of tenth-normal acid to neutralize the ash of 100 grams of vinegar. 

Twenty-two samples of pure cider vinegar were analyzed by A. W. 
Smith* with the following results: 





Acetic 
Acid. 


Total 
SoUds. 


j.^. Alkalinity 
^''^- 1 of Ash.' 


Solub'e 
P2O5. 


Insoluble 
P2O5. 


Total 
P^Oj. 


Maximum 


7.61 

3-24 
4.46 


4.45 0.51 , 55.2 


22.7 
13.6 
19. 1 


19.4 

4-2 
10. 1 


39-° 
19.8 
28.6 




Average 


2.83 


0.39 38.8 



' Number of cubic centimeters of tenth-normal acid required to neutralize the ash from 100 grams 
of vinegar. 

The composicion of cider vinegar ash is found by Doolittle and Hess f 
to be as follows: 

Calcium o.xide CaO 3.4 to 8.21 

Magnesium o.xide ^^gO i-88 " 3.44 

Potassium o.xide K,0 46-33 " 65.64 

Sodium oxide Na^O None 

Sulphuric anhydride. . .. SO3 4.66 to 16.29 

Phosphoric anhydride . . P2O5 3-29" 6.66 

Iron oxide FejO, None " trace 

CO2 and loss 0.00 " 40.44 

Wine Vinegar is light yellow if made from white wine, and red if from 
red wine. The former is the highest prized. Wine vinegar varies in specific 

* Jour. Am. Chem. Soc, 20 (1898), p. 6. 
f Ibid., 22 (1900), p. 220. 



6l2 



FOOD INSPECTION AND ANALYSIS. 



gravity from 1.0129 to 1.02 13, and contains from 6 to 9 per cent of acetic 
acid. It is characterized chiefly by the bitartrate of potassium (cream 
of tartar) which true wine vinegar always possesses. Free tartaric acid 
is also usually present. Wine vinegar is the principal vinegar of France 
and Germany. In the United States the term white wine vinegar is 
usually applied to distilled or spirit vinegar, which is much cheaper than 
the real wine vinegar and altogether inferior to it. 

Wine vinegar is slightly lasvo-rotar)' with polarized light. 

The composition of genuine white wine vinegar is shown by the follow- 
ing summary of the analyses of twenty-two samples, made in the Municipal 
Laboratory of Paris: 





Specific 
Gravity. 


Total 
SoUds. 


Sugar. 


Bitartrate 
of Potash. 


Ash. 


Acidity 
(as Acetic). 


Maximum 


I. 0213 
I. 0129 

1.017s 


3-19 
1.38 

1-93 


0.46 
0.06 
0.22 


0.36 
0.07 
0.17 


o.6g 
0.16 
0.32 


7-38 


Minimum 


4-44 


Mean 


7-38 



Weigmann gives the following average of analyses of red wine \inegar: 



specific 
Gravity. 


Ace tic 
Acid. 


Total 

Tartaric 

Acid. 


Free 

Tartaric 

Acid. 


Cream of 
Tartar. 


Alcohol. Extract. 


Gly- 
cerin. 


Ash. 


Phos- 
phoric 
Acid. 


I. 0143 


7-79 


0.216 


0.006 


O.OS7 


1. 19 


0.863 


0. 141 


0.118 


0.012 



Malt or Beer Vinegar is of a brown color, and its odor is suggestive 
of sour beer. It varies in specific gravity from 1.015 to 1.025; its acidity 
is about the same as cider vinegar, but the extract is much larger, varying 
from 4 to 6 per cent. Malt vinegar contains considerable nitrogenous 
matter, and notable quantities of phosphates, de.xtrin, and maUose. It 
contains no cream of tartar. Malt vinegar is largely used in Great Britian. 

Hehner gives the following data of the analyses of seven samples 
of vinegar undoubtedly made from malt only.* 



Maximum 
Minimum. 
Mean. 



Acidity. 



6.48 
2.88 
4-23 



Total 
Solids. 



4.23 
1.68 

2.70 



Ash. 



0.47 
0.22 
0-34 



Phosphoric 
Anhydride. 



-13 
.067 

-105 



Alkalinity 
(NazCOa). 



* .Analyst, 26, p. 82. See also Analyst, 29, p. 15. 



.017 
.024 



yiNEG^R. 



613 



Allen gives the results of the analyses of three samples of genuine 
vinegar brewed from a mixture of malted and unmalted barley as follows : * 



Specific 
Gravity. 



Acetic 
Acid. 



Total 
Solids. 



Ash. 



Alkalinity 
as K2O. 



Phos- 
phoric 
Acid. 



Nitrogen. 



Albumin- 
oids. 



I. 0170 
1.0228 
I. 0160 



6.39 
5.26 

4- 



.86 



2.67 
3-96 
2-31 



0.34 
0.40 
0.47 



0.091 
0.118 



0.077 
0.093 
0-057 



•099 
-095 
.099 



.624 

.598 
.624 



Distilled, Spirit, or Alcohol Vinegar. — This vinegar, being made from 
diluted alcohol, is nearly colorless, unless artificially colored, as it often 
is, with caramel. As stated on page 612, the "white wine" vinegar (incor- 
rectly so-called) commonly sold in the United States is of this class. Its 
specific gravity ranges from 1.008 to 1.013. Spirit vinegar contains 
from 3 to 10 per cent of acetic acid. Its content of total solids is insig- 
nificant, and it contains only traces of ash. It always contains non- 
acetified alcohol and aldehyde. It has no optical activity with polarized 
light. 

Twelve samples of alcohol vinegar analyzed in the Municipal Labora- 
tory of Paris gave the following results: 



1 Specific 
j Gravity. 


Total 
SoUds. 


Sugar. 


Ash. Acidity. 




0. 16 
0.07 
0-35 


Trace 




Minimum 1 i 0082 


.04 

Trace 


4.98 
6-34 


Mean i .oioo 



Glucose Vinegar is made from the acctification of alcohol, obtained 
from the fermentation of commercial glucose. This vinegar usually 
possesses the odor and taste of fermented starch. It is low in total solids, 
the extract consisting almost entirely of untransformcd glucose, and the 
vinegar therefrom contains all the ingredients of the product from which 
it was made, viz., de.xtrin, maltose, and de.xtrose, as well as sulphate of 
calcium. It is decidedly dcxtro-rotary with polarized light both before 
and after inversion. 

Molasses Vinegar. — This is largely the product of the acetic fermen- 
tation of sugar-house wastes, and sometimes of the accidental acetic 
fermentation of molasses itself, after it has undergone alcoholic fermenta- 
tion for the manufacture of rum. This variety of vinegar is sometimes 



* Analyst, 29, p. 15. 



6i4 FOOD INSPECTION AND ANALYSIS. 

used as an adulterant of cider vinegar. With polarized light molasses 
vinegar is dextro-rotar}' before, and la?vo-rotary after inversion. 

Wood Vinegar is prepared by the purification of pyroligneous acid, 
which may be accomplished by saturating the crude acid wiih lime or soda, 
adding hydrochloric or sulphuric acid, and distilling. It is further purified 
by redistillation with potassium bichromate, and filtration through bone- 
black. Acetic acid is sometimes added to impart flavor. 

The extract and ash of wood vinegar are very small. Its specific 
gravity averages 1.007 according to Blyth. Empyreumatic or tarry 
products are nearly always present in vinegar of this class. 

ANALYSIS OF VINEGAR. 

Specific Gravity. — This is obtained either with the hydrometer, pyc- 
nomctcr, or Westphal balance. 

Determination of Extract or Total Solids. — -Weigh 5 grams of the 
sample in a tared platinum dish, and evaporate to dryness over the live 
steam of a boiling-water bath, keeping the dish thereon for tvvo hours. 
Cool in a dcsicca or and weigh. 

Determination of Ash. — Transfer the dish containing the last residue 
or extract to a muffle, and burn at a low red heat to an ash, or the ignition 
may be accomplished with care over a direct flame turned low. Cool 
the dish and weigh. 

Determination of Solubility and Alkalinity of the Ash. — Smith's 
Method* — Twenty-five cc. of the vinegar arc evaporated to dryness in 
a tared platinum dish, ignited, cooled, and the ash weighed. The ash is 
then repeatedly extracted with hot water by washing into a Gooch crucible 
provided with a layer of asbestos (previously ignited in the crucible, cooled, 
and weighed) or upon an ash-free filter. Drj- the Gooch or filter, ignite, 
cool, and weigh the insoluble ash. The aqueous extract is titrated directly 
with tenth-normal acid, using methyl orange as an indicator, or treated 
by adding an excess of tenth-normal hydrochloric acid, boiling and titrat- 
ing back with tenth-normal sodium hydroxide, using phenolphthalein. 
Express the alkalinity in terms of 100 grams of the vinegar, by multiplying 
by 4 the number of cubic centimeters of acid rcc[uired to neutralize. 

Determination of Phosphoric Acid.f — Extract repeatedly the insoluble 
ash as obtained in the preceding section with hot water acidulated with 
nitric acid, and acidify with nitric acid the neutralized solution of the 

* Jour. Am. Chem. Soc, 20, p. 5. 

t U. S. Dept. of Agric, Bur. of Chem., Bui. 46, p. 12. 



y.'NEGAR. 6 1 5 

soluble ash. Precipitate the phosphoric acid from the two solutions 
separately by adding to each while hot an excess of ammonium molybdate 
(reagent No. 53). Digest for an hour at a temperature of about 65°, filter, 
and wash with a 10% solution of ammonium nitrate. Dissolve the pre- 
cipitate on the filter with ammonia and hot water, and wash into a beaker 
to a bulk of not more than 100 cc. Nearly neutralize with hydrochloric 
acid, cool, and add slowly magnesia mixture (reagent No. 164) drop by 
drop while stirring vigorously. After fifteen minutes add 30 cc. of am- 
monia (specific gravity 0.96), let stand for two hours, filter, wash with 
2.5% ammonia till practically free from chlorides, ignite, and weigh as 
Mg,RO,. ■ 

Express results in terms of milligrams of phosphoric anhydride in 
the soluble and insoluble vinegar ash from 100 grams of vinegar. 

Phosphoric acid in the soluble and insoluble ash may be conveniently 
determined also by the uranium acetate method, page 588. 

Determination of Nitrogen. — Concentrate from 50 to 100 cc. of vine- 
gar to a syrupy consistency, and proceed as directed under the Gunning 
method, page 61. 

Determination of Total Acidity. — Six cc. of vinegar are carefully 
measured from a pipette into a white porcelain dish and diluted with 
water. Using phenolphthalein as an indicator, titrate with tenth-normal 
sodium hydroxide. The number of cubic centimeters of the latter required 
to neutralize, divided by 10, expresses the acidity in terms of percentage 
of acetic acid. 

Approximate Determination of Vinegar Acidity by Lime Water. — It 
has generally been considered difficult for vinegar dealers and others 
who desire to estimate the acidity of their vinegar to do this themselves, 
in that it has been necessary to obtain for the purpose a carefully standard- 
ized alkaline solution, the exact strength of which it is impossible for 
them to determine. 

It has been found that very satisfactory, though of course not abso- 
lutely accurate, results may be obtained by the use of ordinary lime 
water, which any one may easily prepare by making a saturated solution 
of ordinary air-slaked lime. The strength of such a solution is very nearly 
constant, and has been found to be about ^.^ of the normal. If, there- 
fore, it is not easy to obtain exactly normal or tenth-normal alkali, approx- 
imate figures may be obtained by employing such a saturated lime water. 
If 2.75 cc. of vinegar are titrated with lime water contained in a burette, 
using phenolphthalein as an indicator, the number of cubic centimeters 



6i6 FOOD INSPECTION /4ND ANALYSIS. 

of the lime water necessary to neutralize the vinegar, divided by lo, 
gives the percentage of acetic acid in the vinegar. To make sure that 
the lime water is saturated, an excess of lime should always be present 
in the reagent bottle. 

Determination of Volatile and Fixed Acids. — Thirty cc. of the vine- 
gar are transferred to a distilling-flask and subjected to distillation, using 
a current of steam. Receive the distillate in a 25-cc. graduated cylinder. 
After 15 cc. have passed over, test from time to time the drops of 
distillate as they fall into the receiving vessel with litmus-paper, and when 
free from acid discontinue the distillation. Note the volume of the 
distillate, mix by shaking, and transfer one-fifth to a white porcelain dish. 
Titrate as in the case of total acidity, expressing the volatile acids as 
acetic. 

Calculate the fixed acid, expressed in the case of cider vinegar as 
malic, by subtracting the percentage of volatile acid from the percentage 
of total acid, and multiplying the result by the factor 1.117. In the case 
of wine vinegar, express as tartaric acid by using the factor 1.25. To 
express acidity in terms of sulphuric acid, multiply the percentage of 
acetic acid by 0.817. 

Determination of Alcohol. — Alcohol is present in very small amounts 
in fruit vinegar that has not been completely acetified. Frear recom- 
mends concentrating the distillates as follows: Neutralize 100 cc. of 
the sample and distill off 40 cc. Then redistill the distillate till 20 cc. 
have gone over. Cool to 15.6° C. and make up to 20 cc. with distilled 
water. Determine the specific gravity with a lo-cc. pycnometer, and 
ascertain from the table on page 531 the per cent by weight of alcohol 
corresponding to the specific gravity. The percentage in the last distil- 
late, divided by 5, expresses the amount of alcohol in the vinegar. 

Detection of Free Mineral Acids. — The ash of genuine cider vinegar 
is always alkaline. If the ash is neutral, free mineral acids are doubtless 
present. For their detection the following is a modification of Brannt's 
method of procedure: 

Add to 50 cc. of the vinegar in an Erlenmeyer flask a small bit of 
starch the size of a wheat-grain, and shake to disseminate it through the 
fluid. Boil for some minutes, cool, and add a drop of iodine solution. 
If a blue coloration occurs, no mineral acid is present. In the presence 
of an appreciable amount of mineral acid, the starch will be converted 
to dextrin and sugar, and no coloration will be produced by the iodine. 

Frear's Method-. — Add 5 or 10 cc. of water to 5 cc. of the vinegar, and 



yiNEGAR. 617 

to the mixture add a few drops of a solution of methyl violet (one part 
of methyl violet 2B in 100,000 parts of water). In the presence of mineral 
acids, a blue or green coloration will be produced. 

Determination of Free Mineral Acids. — Hehner's Method.*— To a 
weighed quantity of the sample add an excess of decinormal alkali, evap- 
orate to dryness, incinerate, and titrate the ash with decinormal acid. 
The difference between the number of cubic centimeters of alkali added 
in the first place, and the number of cubic centimeters needed to titrate 
the ash, represents the equivalent of the free acid present. 

Detection and Determination of Sulphuric Acid. — This is determined 
as barium sulphate by the addition of barium chloride solution. A slight 
cloudiness on the addition of the reagent indicates the presence of 
small quantities of sulphate as an impurity, rather than free sulphuric 
acid. If a minute quantity of free sulphuric acid be present, a rather 
heavy white cloud on the addition of the barium chloride will be formed, 
which slowly settles out. According to Brannt, if the quantity of sul- 
phuric acid is more than one part in a thousand, the sulphate of barium 
formed by addition of the reagent produces a copious precipitate that 
rapidly falls to the bottom of the receptacle. ■ This may be filtered, 
washed, ignited, and weighed in the usual manner. 

Detection of Free Hydrochloric Acid. — Distill off half of a measured 
volume of vinegar into the rcceiving-tlask of a distillation apparatus, 
and to the distillate add a few drops of nitrate of silver reagent. A pre- 
cipitate indicates hydrochloric acid. 

Detection of Malic Acid {Free or Combined). — .\bsence of malic acid 
may be assured, if no precipitate occurs with neutral acetate of lead, 
when a few drops of a solution of this reagent are added to the vinegar. 
In the presence of malic acid, as in the case of a pure cider vinegar, the 
precipitate which is formed with lead acetate is flocculent, forms at once, 
and is of considerable amount. In pure cider vinegar the precipitate 
will settle to the bottom of the test-tube, leaving a clear supernatant 
liquid within ten minutes. Unfortunately the acetate of lead test is 
a negative one, in that several organic acids other than malic will cause 
a precipitate, as, for instance, tartaric and saccharic acids, the former 
being found in wine and the latter in molasses vinegar. ]\Ialt vinegar 
also gives a copious precipitate with lead acetate, due to phosphoric acid. 

The writer employs the following test f for detecting malic acid in 

* Analyst, i, 1877, p. 105. 

t An. Rep. Mass. State Board of Health, 1902, p. 4S5. Food and Drug Reprint, p. j^. 



6l8 FOOD INSPECTION AND ANALYSIS. 

vinegar: Add a few drops of a io% solution of calcium chloride to some 
of the vinegar in a test-tube, and make the mixture slightly alkaline with 
ammonia. Fiher off the precipitate that occurs at this point, to the 
filtrate add two or three volumes of 95% alcohol, and heat to boiling. 
A copious, flocculent precipitate of^ calcium malate will form, if malic 
acid be present, settling to the bottom of the tube in a few minutes. 
A precipitate will occur in maU and glucose vinegar, due to dextrin. 

To confirm the presence of malic acid, filter, wash the precipitate 
with a little alcohol, dry, dissolve it in strong nitric acid in a porcelain 
evaporating-dish, and evaporate to diyness over the water-bath, forming 
calcium oxalate. Boil the residue with sodium carbonate, filter, acidify 
the filtrate with acetic acid, boil to expel the carbon dioxide, and add a 
solution of calcium sulphate. A precipitate of calcium oxalate confirms 
the presence of malic acid. 

For the determination of malic acid proceed as directed on page 569. 

Determination of Acid Tartrate of Potassium. — Berthelot and Fleu- 
rien's Method* — Twenty-five cc. of the vinegar are evaporated on the 
water-bath to syrupy consistency, and the residue is dissolved in water 
and made up to its original volume. It is then transferred to a 250-cc. 
Erlenmeyer flask, and 100 cc. of a mixture of equal parts of strong alcohol 
and ether are added, the flask is corked, shaken, and set on ice or in a 
cold place for forty-eight hours. At the end of this time, if a crystalline 
precipitate has gathered, the supernatant liquid is decanted upon a filter, 
and finally the precipitate is washed upon it by a fresh quantity of the 
ether-alcohol mixture, and the washing continued with this reagent till 
practically free from acid. The filter and its contents are then trans- 
ferred to the original flask, and the tartrate is dissolved in boiling water, 
after which the solution is titrated in the same flask with tenth-normal 
sodium hydroxide, using phenolphthalein as an indicator. Multiply 
the number of cubic centimeters of alkali required to neutralize by the 
factor 0.0188, and the quotient expresses the grams of bitartrate of potash 
in the sample. Multiply this by 4 to obtain the percentage present. 

Polarization and Determination of Sugar.— If the vinegar is light- 
colored and quite free from turbidity, it may sometimes be polarized undi- 
luted in the loo-mm. tube. Vinegar may often be sufficiently clarified 
for polarization by filtering twice through the same filter. It is, how- 
ever best to add 10% of basic lead acetate solution, and to filter before 
polarizing, thus removing the malic or tartaric acids which may have a 

* Girard et Dupre, Analyse des Matieres Alimentaires, p. 128. 



yiNEG/IR. 6ig 

slight effect on the polarization. In case of dark-colored or turbid 
samples, add to 50 cc. of the sample 5 cc. of about equal quantities of 
lead subacetate and alumina cream, shake, filter, and polarize in a 200- 
mm. tube, adding 10% to the reading on account of the dilution. 
The polarization value of the vinegar is conveniently expressed in terms 
of actual direct reading obtained by the undiluted sample in a 200- or 
400-mm. tube. 

If the invert reading is desired for calculation of sucrose or com- 
mercial glucose, subject the sample to inversion with hydrochloric acid 
and heat, as in the case of sugars. 

For the determination of sucrose, use Clerget's formula (p. 483), 
calculating the true direct and invert readings from the direct a;nd invert 
readings of the undiluted vinegar on the basis of the normal weight of 
the sample, by multiplying the obtained readings by 0.26 in the case of the 
Soleil-Ventzke instrument. 

Determination of Reducing Sugars before and after Inversion. — Two 
portions of 25 cc. each are measured into loo-cc. flasks. One portion is 
diluted with 25 cc. of water, 5 cc. of concentrated hydrochloric acid are 
added, and the solution subjected to inversion by heating to 70° for 10 
minutes and cooling. Both portions are neutralized with sodium 
hydroxide and made up to the mark.. The reducing sugars are deter- 
mined in each portion by Defren's modification of O'SuUivan's method 
(page 489) and calculated as dextrose. 

Levulose may be determined as on page 508, polarizing the vinegar 
at two different temperatures. 

ADULTERATION OF VINEGAR. 

Standards of Purity. — In nearly all localities where pure-food laws 
prevail there are special provisions setting forth the requirements of prre 
vinegar as to percentage of acids, solids, and other conditions, differing 
considerably with the character of the vinegar used. Thus, in England, 
where the principal vinegar is malt vinegar, the legal standards are con- 
siderably different from those in force in France and Germany, where 
wine vinegar is prevalent. These differ again from the requirements 
found in the United States and Canada, where cider vinegar is the chief 
product. 

Most of the state food laws fix a standard for the acidity of cider 
vinegar varj'ing from 3.5 to 4.5 per cent of acetic acid, and in most cases 
also a minimum standard for total solids or residue of from 1.5 to 2 per 



do FOOD INSPECTION AND /tN/ILYSlS. 

cent. Special laws stipulate furthermore in some states that cider vine- 
gar, sold as such, must be exclusively the product of pure apple cider. 
In such cases cider vinegar may be adulterated by non-conformance 
to the standard in either acidity or solids or both, while yet it may be 
exclusively made from pure apple cider. This may be due either to 
actual watering or to incomplete acetification. On the other hand, so- 
called cider vinegar may be of legal standard as to solids and acidity, 
and yet be entirely spurious. 

Accidental Adulteration of vinegar may result in the presence of injuri- 
ous metallic salts, such as of copper, lead, or zinc, derived from vessels or 
utensils used in the manufacture of vinegar, or even minute traces of 
arsenic may be found, when glucose has been employed as an ingredient 
or source of the vinegar, the arsenic being in this case probably due to 
impure sulphuric acid used in the manufacture of the glucose. 

Willful or Fraudulent Adulteration is, however, common, in which 
misbranded vinegar is sold under names suggesting a class other than 
that to which it really belongs, or wherein entirely artificial substitutes 
are made up for pure cider, malt, or wine vinegar, in which the color, 
residue, and acid principle may be either or all of spurious origin. 

Artificial Cider Vinegar is in most cases readily detected, though 
very ingenious imitations are on the market, involving not a little skill 
and chemical knowledge in their manufacture. 

Entirely artificial substitutes for cider vinegar are frequently made 
up of spirit vinegar, colored with caramel, and having the solids rein- 
forced by apple jelly, made for the most part out of exhausted apple 
pomace, which is the residue left after the apple-stock has been sub- 
jected to one and sometimes two pressings. The jelly used for this 
puqjose is not infrequently made up with commercial glucose. All 
grades of adulterated vinegar arc to be found, from the wholly 
spurious substitute above described, to the varieties in which cider 
vinegar is itself present, but is pieced out or reinforced by the admixture 
of coloring matter, mineral acid, wood vinegar, or of molasses or glucose 
vinegar. Acetic ether is sometimes employed to impart flavor to the 
product. All the characteristics of a pure cider vinegar are difficult to 
duplicate artificially, though some of them may be. 

Character of the Residue. — The residue of pure cider vinegar should 
be thick, light brown in color, of a viscid or mucilaginous consistency, 
somewhat foamy, having an astringent acid though pleasant taste very 
suggestive of baked apples, which it also resembles in odor. The odor 



ytNEGAR. 621 

of molasses is very apparent in the residue of vinegar having sugar-house 
wastes, and the smell of a malt-vinegar residue is also very characteristic. 
If pyroligneous or wood vinegar has been introduced, the dried residue 
will have a tarry or smoky taste and smell. 

The residue of cider vinegar is very soluble in alcohol, while that of malt 
vinegar is only slightly soluble. Wine vinegar residues dissolve readily 
in alcohol, except for the granular residue of cream of tartar. If the 
loop of a clean platinum wire be rubbed in the vinegar residue and ignited 
in a colorless Bunsen flame, the color imparted will, if the vinegar has 
been made from pure cider exclusively, consist altogether of the pale- 
lilac color of a potash salt without any of the yellow sodium flame being 
visible. In all vinegars other than of pure cider, the sodium flame will 
predominate, when the residue is burnt as above. Again, the ignited 
residue left in the loop of wire in the case of a pure cider vinegar will 
form a fusible bead, having a strong alkaline reaction upon moistened 
test-paper, and effervescing briskly when immersed in acid. The pres- 
ence in vinegar of even a slight trace of added mineral acid will prevent 
the ignited residue from having the alkaline reaction, or effervescing with 
acid.* 

The residue of malt or beer vinegar is brown and gummy, containing 
a considerable quantity of dextrin. Not only are the appearance and 
odor of the dried vinegar residue to be particularly noted, but also the 
odor given off in the first stages of burning this residue to an ash. With 
cider vinegar the apple odor is very marked while burning. In vinegar 
wherein molasses products have been employed, the smell of charred 
sugar is usually apparent, while with glucose vinegar the smell of burnt 
corn predominates. 

On burning the residue of malt vinegar, the odor produced at first 
is not unlike that of toasted bread. At a later stage in the burning the 
vapors evolved are ver\' pungent. 

The Character of the Ash is of considerable importance in determin- 
ing the source of a sample of vinegar. The ash of pure cider and malt 
vinegar is quite strongly alkaline, while that of distilled and wood vinegar 
is only slightly alkaline. The ash of cider vinegar is high in alkaline 
carbonates. 

In cider and malt vinegar the quantity of phosphoric acid present 
in the ash is considerable, while only traces are present in distilled or 
spirit vinegar. Considerably more than half the phosphoric acid in 

* Davenport, iSth An. Rep., Mass. Board of Health, 1887, p. 159. 



62 2 FOOD INSPECTION MND ANALYSIS. 

the ash of cider vinegar is soluble, while no soluble phosphoric acid is 
present in the ash of spirit vinegar. 

The percentage of ash in total solids is of some value in judging the 
purity of cider vinegar. According to Frear * if the ash of the vinegar 
is less than io% of the total solids, the vinegar may be suspected of 
having added unfermented material, while a percentage of ash less than 
6 is absolute evidence that the vinegar is not genuine cider vinegar. 

The alkalinity of i gram of the ash of pure cider vinegar should be 
equivalent to at least 65 cc. of tenth-normal acid. At least 50% of 
the phosphates in the ash should be soluble in vi^ater. 

Character of the Sugars. — One of the most important steps in es- 
tablishing the source of a vinegar consists in subjecting it to polariza- 
tion (p. 618). From the nature of the sugar-content of the apple juice, 
not only when freshly expressed, but also when allowed to undergo 
alcoholic fermentation, and, furthermore, after it has gone over into 
vinegar, the polarization through all three stages is always left-handed. 

Browne f has shown that the optical rotation of the freshly expressed 
juice of eleven varieties of apple varies from 19.24° to 49° to the left oA 
the Ventzke scale, in a 400-mm. tube. Also that in the case of five 
samples of completely fermented cider, examined five or six months 
after pressing, the left-handed rotation in a 400-mm. tube varied from 
1.76° to 5.28°. He showed, furthermore, that a sample of pure cider 
jelly made up of concentrated apple juice had a left-handed rotation 
amounting to 21.35° i^i a 200-mm. tube (20 grams made up 100 cc), and 
finally that four cider vinegar samples of known purity showed left- 
handed readings of from 0.96° to 2.94° Ventzke in a 400-mm. tube. 

The left-handed rotation of pure cider vinegar is a characteristic so 
fixed and unalterable that a right-handed polarization of more than 0.5° 
may safely be assumed as evidence of adulteration. The polarization of 
cider vinegar, expressed in terms of 200 mm. of the undiluted sample 
should lie between —0.1° and —4.0° Ventzke. If the direct polarization 
of a sample of vinegar is right-handed, while the invert is left-handed, 
sugar-house wastes or molasses may be suspected as an adulterant. 

If both direct and invert readings are right-handed, commercial 
glucose is undoubtedly present. If the polarization of the vinegar is 
far to the left, unfermented cider jelly has probably been used to rein- 
force the solids. 

* Report of Penn. Dept. of Agric, 1898, p. 38. 

t Bui. 5S, Penn. Dept. of Agric, "A Chemical Study of the Apple and Its Products.'' 



yiNEG/lR. 



623 



Frear regards the ratio of reducing sugars after inversion to total 
solids as a useful factor in discriminating between pure cider vinegar 
and the common artificial substitutes in which the solids of distilled vinegar 
are reinforced by apple jelly, or in which commercial glucose or molasses 
vinegars are used. When the reducing sugars after inversion form more 
than 25% of the entire solids, the alleged cider vinegar is undoubtedly 
spurious. In pure cider vinegar the per cent of reducing sugar is the 
same after inversion as before. The same is true of glucose vinegar. 

Vinegar containing added molasses or cane sugar will, however, 
naturally show an increase in reducing sugar after inversion. 

A large content of alcohol in cider vinegar, otherwise showing the 
constants of pure vinegar except for the low acidity, would indicate incom- 
plete acetification. A high content of nitrogen is characteristic of malt 
vinegar. 

.Data of analyses of samples of vinegar examined in the Food and 
Drug Department of the Massachusetts State Board of Health are given 
in the tables on this page and the next. The table below shows in sum- 
marized form the results obtained from the examination of eighty-four 
samples of undoubtedly pure cider vinegar examined in 1901.* 

CIDER VINEGAR FOUND PURE. 





Acid 
(Per Cent). 


Solids 
(Per Cent). 


Ash 
(Per Cent). 


Polarization. 


Maximum 


6.36 

4-5° 
4-84 


4.00 
2.01 
2-43 


0.58 
0.19 
0.38 


-5-4 
— 0.4 


Mean 


— 2.0 







The second table includes samples of adulterated vinegar, sold for 
cider vinegar, none of which were probably made from cider. It will 
be noticed that in several of the samples the amount of glucose was 
abnormally large, as is shown by the very high right-handed polarization, 
in one case amounting to over 12°. 

Direct Tests Made on the Vinegar. — The genuine or spurious nature 
of cider vinegar may usually be established by direct tests with reagents 
on the vinegar itself. The appearance, taste, and odor of the vinegar 
should be noted. Brannt f applies the test of odor in vinegar as deter- 

* 32d An. Rep. (igoo), p. 66i, Food and Drug Reprint, p. 44; 33d An. Rep. (iqoi), p. 
467, Food and Drug Reprint, p. 47; 34th An. Rep. (1902), p. 483, Food and Drug Reprint, 
p. 31. 

t A Practical Treatise on the Manufacture of Vinegar, p. 219. 



624 FOOD INSPECTION AND ANALYSIS. 

VINEGAR NOT THE EXCLUSIVE PRODUCT OF PURE APPLE CIDER. 



Per Cent 


Per Cent 


Per Cent 


Per Cent 


Polarization 




Acetic Acid. 


Total Solids. 


Ash. 


Ash in Total 
Solids. 


in 200-mm. 
Tube. 


Lead Acetate. 


5-9° 


.40 


.... 


.... 


+ 1.4 


No precipitate 


S-I4 


-36 




.... 


.0 


* ' ' ' 


5-12 


•S3 





.... 


+ .6 


it a 


4.83 


3-70 


-32 


8.65 


+ 8.0:; 


" 


4.82 


2.71 


-13 


4.80 


+ 9.6:: 


Heavy precipitate* 


4.80 


1-97 


.20 


10.15 


+ .9 


Precipitate 


4.80 


i-°3 


-27 


14-75 


+ 1.1 


* ' 


4.66 


2.92 


.20 


6.49 


+ 2.2 


No precipitate 


4.60 


2-57 


.... 




+ 2.6 


" " 


4-56 


2.60 




.... 


+ 7-ot 


t 


4-54 


3-97 


.19 


4.78 


+ 5-6 


No precipitate 


4-54 


3-9° 


•32 


9.72 


+ S-° 


> ' tt 


4-54 


2-94 


-23 


7.82 


+ 5-° 


( ( * t 


4-54 


2.70 


-23 


8.52 


+ .4 


Precipitate 


4.50 


3-°5 






+ 2.2 


No precipitate 


4-50 


2.92 


.22 


7-52 


+ -9 


* ' ' ' 


4-5° 


2.69 






+ 2.8 


( ( ( ( 


4-48 


3.80 




.... 


-f 12.0+ 


t ( ( ( 


4.46 


2.80 




.... 


4-2.6 


(( " 


4.42 


2-75 





.... 


+ 3-2 


Slight precipitate 


4.42 


2.10 








■f9.2 


Precipitate 


4-4° 


2-51 


.20 


II. 15 


+ I.I 


* ' 


4-4° 


-97 






+ -4 


No precipitate 


4-38 


.29 


.... 


.... 


4-1.6 


( ( ( i 


4-32 


■70 


.09 


12.86 





" ' ' 


4.08 


3-35 


.... 




-f 1.2 


Precipitate 


3-98 


-55 







+ 1.8 


Slight precipitate 



* Cider vinegar to which apple jelly containing glucose had been added for the purpose of increas- 
ing the solids after watering. 

t This sample contained a large amount of phosphate, and consequently the test for malates is 
obscured. 

X These samples polarized practically the same after as before inversion, indicating much glucose. 

mining its character, by rinsing out a large beaker with the sample, and, 
after allowing it to stand for some hours, examining the few drops remain- 
ing in the beaker. The acetic acid having for the most part become 
volatilized, the characteristic vinous odor of pure wine vinegar would 
at this stage be ver)' prominent, while that of cider vinegar would be 
entirely different. The odor of the two vinegars is very similar in their 
ordinary state. The peculiar fruity flavor of pure cider vinegar is very 
characteristic and not readily imitated by cheaper substitutes. Only 
a very slight turbidity should be produced in pure cider vinegar by the 
addition of either ammonium oxalate (absence of lime), barium chloride 
(absence of sulphuric acid or sulphate), and nitrate of silver (absence 
of hydrochloric acid or chlorides). 

Vinegar in which glucose has been used nearly always gives a precipi- 
tate with ammonium oxalate, due to the sulphate of calcium present. 



yiNEGAR. 625 

The character of the precipitate produced by neutral lead acetate 
should be particularly noted. Unless it is flocculent and copious, set- 
tling out after a few minutes, cider vinegar is not pure, even if a marked 
turbidity is produced. Added apple jelly from exhausted apple pomace 
gives such a turbidity, and is to be suspected when not more than a cloudi- 
ness is produced on addition of the lead acetate reagent. Pure cider 
vinegar should respond in a perfectly normal manner to both the lead 
acetate and the calcium chloride tests for malic acid. 

Wood Vinegar or Pyroligneous Acid is sometimes rendered apparent 
by the cmpyreumatic or tarry tas'.e and odor imparted to the product. 
When, however, the added acetic acid has been so purified that tlie tarry 
taste and odor are lacking, its presence may often be proved by the traces 
of furfurol which always accompany it. 

Test jor Furjurol. — A little of the vinegar is subjected to distillation, 
and to the first few drops of the distillate is added a little colorless anilin 
solution. A fading crimson color will be produced in presence of furfurol. 
This reaction may sometimes be obtained upon the vinegar itself without 
distillation, if sufficient added wood vinegar be present. 

The first portion of the distillate of wood vinegar reduces permanga- 
nate of potassium to a marked degree. 

The Addition of Spices to vinegar in order to increase the pungency 
is best detected by first neutralizing the vinegar with sodium carbonate 
and then tasting. Under these conditions, the admixture of spices is 
rendered very apparent. 

Detection of Caramel. — Considerable added caramel in vinegar is 
apparent from the unnaturally dark color and extremely bitter taste of 
the residue after evaporation. 

Tests for caramel made on the vinegar residue, if long dried at the 
temperature of the water-bath, are not to be depended on as establishing 
the presence of added caramel, since at that temperature the decomposi- 
tion of the sugar may in any event cause a positive test. 

Caramel in vinegar is best detected by the Crampton and Simons' 
method with fullers' earth, as described on page 603. Other methods 
arc given in Chapter XVI. 

Examination for Metallic Impurities. — Lead and Zinc are best looked 
for in the ash of the vinegar in cases where, like cider vinegar, the percent- 
age of extract is high. A large volume of the vinegar is evaporated to 
substantial dryness over the water-bath. This may most readily be 
done in a loo-cc. platinum wine-shell, adding the vinegar in successive 



626 FOOD INSPECTION AND ANALYSIS. 

portions. To the residue add a small amount of sodium hydroxide, and 
burn to an ash in a muffle, or over a low flame, using potassium nitrate 
if necessary, a little at a time. Take up the ash in dilute hydrochloric 
acid, and examine for lead and zinc as in the case of canned goods. 

In the case of vinegar low in extract, as in spirit vinegar, the sample 
may be evaporated to drj'ness, the residue dissolved directly in dilute 
hydrochloric acid without ignition, and the acid solution subjected to 
direct examination for lead and zinc. 

Copper is best determined by electrolysis. loo cc. of the vinegar 
are evaporated to a volume of about lo cc. with a little sulphuric acid, 
filtered into a platinum dish, and subjected to electrolysis, using con- 
veniently the apparatus described on page 493. 

Arsenic. — Boil down a portion of the vinegar, to which concentrated 
nitric acid has been added, to a small volume, then add a few cubic centi- 
meters of concentrated sulphuric acid, and continue the heating till fumes 
of sulphuric acid show the nitric to have been driven off. Cool, dilute 
with water, and test in the Marsh apparatus. 

REFERENCES ON VINEGAR. 

Allen, A. H. White Wine Vinegar. Analyst, 21, 1896, p. 253. 

Allen, A. H., and Moor, C. G. Vinegar. Analyst, 18, 1893, pp. 180 and 240. 

Bersch, J. Die Essigfabrikation. Vienna, 1895. 

Brannt, W. Vinegar, Acetates, Cider, Fruit Wines and Preservation of Fruits. 

London, 1900. 
Browne, C. A. A Chemical Study of the Apple and Its Products. Penn. Dept. of 

Agric. Bui. 58, 1899. 
Crampton, C. a., and Simons, F. D. Detection of Caramel in Spirits and Vinegar 

Jour. Am. Chem. Soc, 21, 1899, p. 355. 
Davenport, B. F. Analysis of Vinegar. Chem. News, 1887, 3, and 66. 
DooLlTTLE, R. E., and Hess, W. H. Cider Vinegar, Its Solids and Ash. Jour. Am. 

Chem. Soc, 22, 1900, p. 218. 
Feear, W. Apple Juice, Fermented Cider and Vinegar. Penn. Dept. of Agric. 

Rep., 1898, p. 138. 

Cider Vinegars of Pennsylvania. Penn. Dept. of Agric. Bui. 22, 1897. 

Vinegar. U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 62. Washington, 

1902. 
Gardner, J. Acetic Acid and Vinegar. Phila., 1885. 
Leach, A. E., and Lythgoe, H. C. Cider Vinegar and Suggested Standards of Purity. 

Jour. Am. Chem. Soc, 26 (1904), p. 375. 
Leeds, A. R. Acetic Acid in Vinegar. Jour. Am. Chem. Soc, 17, 1895, p. 741. 
Macfarlane, T. Vinegar. Canada Inl. Rev. Dept. Bui. 35. Ottawa, 1893. 
Pastexjr, M. Etudes sur la Vinaigre. Paris, 1868. 



yiNEG/tR. 627 

SANGLE-FERKiiRE. Vinaigre. Analyse des Matiferes Alimentaires (Girard et Dupr^, 

P- 237- 
Smith, A. W. Vinegar Analysis and Characteristics of Pure Cider Vinegar. Jour. Am. 

Chem. Soc, 20, i8gS, p. 3. 
Sykes, W. J. Detection of Adulteration in Vinegar. Analyst, 16, 1891, p. 83. 

Connecticut E.xp. Sta. An. Reports, 1897, 1898, 1899. 

Massachusetts State Board of Health, An. Reports, 1900, 1901, 1902, and 1903. 

North Carolina Exp. Station Bui. 163. 



CHAPTER XVI. 
ARTIFICIAL FOOD COLORS. 

The use of artificial dycstufTs in food products has greatly increased 
during the last decade, both in degree and in variety of colors employed. 
Where formerly but a few well-known coloring matters, chiefly so-called 
vegetable colors and occasionally mineral pigments were used for this 
purpose, a vast array of dyes, chosen largely from the coal-tar colors, 
arc now found in food, so that at present the exact identification of the 
particular dyestufif employed in all cases presents a somewhat formidable 
problem to the analyst. The problem may consist in determining the 
class to which a commercial food color or combination of colors belongs, 
or it may consist in isolating the color itself, and afterwards identifying 
it as far as possible, for the purpose of determining whether or not it is 
harmless within the meaning of the law. 

The effect of imparting to the cheaper varieties of jellies, jams, and 
ketchups which flood the market such intense and striking colors that 
these products in no wise resemble their pure uncolored prototypes, has 
a tendency in many cases to mislead the public into the idea that the 
genuine products are inferior by contrast, and to create a craving for 
unnaturally colored varieties. Indeed, the adherents to the free use of 
coloring matters in food assert that these brilliant hues please the eye and 
are hence legitimate. 

Objectionable Features. — With the exception of confectionery and 
certain dessert preparations, in which dyes may be employed purely for 
aesthetic considerations only (a fact which is well understood by the 
consumer), the use of coloring matters in food is mainly for the purpose 
of deceiving as to their true character. The use of dyestuffs in food 
is objectionable on two accounts, first as introducing in some cases 
materials injurious to health, and second, in nearly all cases as deceiv- 
ing the purchaser by concealing inferiority, or by making the goods 

628 



ARTIFICIAL FOOD COLORS. ' 629 

appear of greater value than they really are. In most states the food 
laws regarding employment of colors are so framed, that the presence 
of such colors constitutes an offense under one or the other of the above 
heads, mainly, however, because, by reason of their use, cheaper or 
inferior materials are made to masquerade for the higher or genuine 
grades, as, for instance, when alleged currant jelly is found to consist 
chiefly of apple-stock and commercial glucose, colored with an artificial 
red dye. 

In such cases the analyst has merely to prove conclusively that an 
artificial color is present, even if he does not identify the dye itself. It 
is of course more satisfactory to at least show in addition whether the 
dye present is of vegetable origin, or is of the coal-tar variety, and in most 
cases this can readily be done, even if it is not easy to identify the exact 
color. 

In localities where laws prevail stipulating that what are commonly 
known as "mixtures" or "compounds" to be legally sold, must be 
labeled with the names and percentages of ingredients, the law applies to 
coloring matters as well as other ingredients, and the exact dye or dyes 
employed should appear on the label. Otherwise the product must be 
classed as adulterated. 

Toxic Effects of Colors. — Formerly the use of such pigments as 
chromate of lead was common in coloring confectionery, but lead 
chromate is rarely used at present. Other mineral pigments obviously 
unfit for use in food by reason of their well-known poisonous effects are 
those which contain salts of arsenic, mercury, lead, and copper. While 
most of the coal-tar colors are considered harmless in themselves, some 
are decidedly objectionable, and should not be used in foods. Under 
the latter class are included, first, those in connection with the manu- 
facture of which arsenic, mercury, or other poisonous mineral ingredients 
have been used, such for example as arsenical fuchsin, and, second, those 
which are themselves inherently poisonous, as for instance picric acid. 
Fuchsin is now largely made without the aid of arsenic acid, and this 
variety is entirely harmless. The toxic effects of many of the coal-tar 
colors have not been thoroughly established excepting in a negative way. 
Weyl has made many experiments on dogs and rabbits in which these 
animals have been fed with varying amounts of coloring material. In 
nearly all cases the doses far exceeded the amounts ordinarily taken in 
food, and the experiments arc of value mainly in so far as they show 
harmless results of certain colors on the animal. It is to be regretted 



C^d FOOD INSPECTION AND ANALYSIS. 

that physiological experiments cannot more readily be tried on human 
beings, so as to study the efiects of administering to them such amounts 
as are used in food. 

More conclusive results (though still of a negative character) tending 
to establish the harmlessness of most of the coal-tar colors are given by 
Grandhomme * in statistics showing the condition of health of laborers 
in factories where these dyestuffs are made, in comparison with those 
engaged in other industries where poisonous materials are handled. 
From these it appears that the proportion of illness among the anilin- 
makers is remarkably small. 

In the case of coloring confectionery by the use of mineral pigments, 
a considerable amount of the coloring material must be used, forming 
without doubt a source of danger in some cases. With coal-tar dyes, on 
the contrary, the case is different. One ounce of auramine, for instance, 
has been found sufficient to give a deep-yellow color to 2,000 pounds 
of confectionery, so that almost an infinitesimal amount of the actual 
dyestuff is taken into the system. Hence it is that very little danger 
need be apprehended from the use of most coal-tar colors in food, objec- 
tionable as they certainly are as a commercial fraud. 

Injurious and Non-injurious Colors. — Various countries have enacted 
specific laws regulating the use of coloring matters in foods, especially 
England, France, Germany, Austria, and Italy. In some cases attempts 
have been made to specify harmful and harmless colors. The National 
Confectioners' Association of the United States has compiled a useful 
classified list of injurious and harmless colors,t the classiiication being 
based largely on the results of experiments by Weyl and Konig, as well 
as upon the Resolutions of the Association of Swiss Chemists, and on 
the French Ordinances regarding food colors. The list is as follows: 

HARMFUL MINERAL COLORS. 

Compounds oj Copper. — Blue ashes, mountain blue, etc. 

Compounds oj Lead. — Massicot, red lead, white lead, Cassel yellow, 
Paris yellow. Turner yellow, Naples yellow, sulphates of lead, chrome 
yellow, Cologne yellow, etc. 

Compounds oj Barium. — Ultramarine yellow, etc. 

* Weyl, Sanitary Relations of the Coal-tar Colors, pp. 28-30. 

t Colors in Confectionery. An Official Circular from the Executive Committee of the 
National Confectioners' Association of the U. S., 1899. 



ARTIFICML FOOD COLORS. 631 

Compounds oj Mercury. — Vermilion, etc. 

Compounds oj Arsenic. — Scheele's green, Schweinfurth green, etc. 
In Other Words colors in whose preparation mercury, lead, copper, 
arsenic, antimony, tin, zinc, chromium, and barium compounds are used. 



HARMFUL ORGANIC COLORS. 

Red Colors. — Ponceau s^B. — Ponceau B extra, fast ponceau B, 
new led L, scarlet EC, imperial scarlet, old scarlet, Biebrich scarlet. 

Crocein Scarlet ^B. — Ponceau 4RB. 

Cochenille Red A. — Crocein scarlet 4B and G, brilliant scarlet, 
brilliant ponceau 4R, ponceau 4R, ponceau brilliant 4R, new coccin, 
scarlet. 

Crocein Scarlet 75. ^Crocein scarlet 8B, ponceau 6RB. 

Crocein scarlet O extra. 

Safranin. — Safranin T, safranin extra G, safranin G extra GGSS, 
safranin GOOO, safranin FF extra No. O, safranin cone, safranin AG 
extra, safranin AGT extra, anilin pink. 

Yellow Colors. — Gum gutta. 

Picric acid. 

Martius Yellow. — Naphthylamin yellow, jaune d'or, Manchester yel- 
low, naphlhalin yellow, naphthol yellow, jaune naphthol. 

Acme Yellow. — Chrysoin, chryseolin yellow T, gold yellow, resorcin 
yellow, acid yellow RS, tropjeolin O, jaune II. 

Victoria Yellow. — Victoria orange, anilin orange, dinitrocresol, saf- 
fron substitute, golden yellow. 

Orange II. — Orange No. 2, orange P, orange extra, orange A, orange 
G, acid orange, gold orange, mandarin G extra, beta-naphtholorange, 
tropasolin 000 No. 2, mandarin, chrysaurin. 

Metanil Yellow. — Orange MN, tropaeolin G, Victoria yellow (O double 
cone), jaune G (metanil extra). 

Sudan I. — Carminnaphte. 

Orange IV. — Orange No. 4, orange N, orange GS, new yellow, acid 
yellow D, tropaeolin 00, fast yellow, diphenylorange, diphenylamine 
orange, jaune d'anilin, anilin yellow. 

Green Colors. — NapJitbol green B. 

Blue Colors. — Methylene blue BBG. — Methylene blue BB, in powder 
extra, methylene blue DBB extra, methylene blue BB (crystalline) 
ethylene blue. 



632 FOOD INSPECTION AND ANALYSIS. 

Brown Colors. — Bismarck Brown. — Bismarck brown G, Manchester 
brown, phenylen brown, vesuvin, anilin brown, leather brown, cinnamon 
brown, canellc, English brown, gold brown. 

Vesuvin B. — Manchester brown EE, Manchester brown PS, Bis- 
marck brown, Bismarck brown T, brun Bismarck EE. 

Fast Brown G. — Acid brown. 

Chrysoidin. — Chrysoidin G, chrysoidin R, chrysoidin J, chrysoidin Y. 

HARMLESS MINERAL COLORS. 

Blue Colors. — Ultramarine blue. 

Violet Colors. — Ultramarine violet. 

Brown Colors. — Manganese brown. 

Chocolate-brown and colors of a similar nature have as their basis 
natural or precipitated oxide of iron, which in an impure condition may 
have small quantities of arsenic in its composition. It is possible with 
proper care to secure a raw material entirely free from this objectionable 
element, and no oxide of iron containing any traces of arsenic should 
be used in the preparation of color. 

Green Colors. — Ultramarine green. 

HARMLESS ORGANIC COLORS. 

Red Colors. — Cochineal carmine. 

Carthamic acid (from saffron). 

Redwood. 

Artificial alizarin and purpurln. 

Cherry and bed juices. 

Eosin. — Eosin A, eosin G extra, eosin GGF, eosin water soluble, eosin 
3J, eosin 4J extra, eosin extra, eosin KS ord., eosin DH, eosin JJF. 

Erythrosin. — Erythrosin D, erythrosin B, pyrosin B, primrose solu- 
ble, eosin bluish, eosin J, dianthin B. 

Rose Bengale. — Rose bengale N, Rose bengale AT, rose bengale G, 
bengalrosa. 

Phloxin. — Phloxin TA, eosin blue, cyanosin, eosin loB. 

Bordeaux and Ponceau reds, resulting from the action of naphthol- 
sulphonic acids on diazoxylene : 

Ponceau 2R. — Ponceau G, ponceau GR. 
Ponceau R. — Brilliant ponceau G, ponceau J. 



ARTlFia/(L FOOD COLORS. 633 

Bordeaux B. — Fast red B, Bordeaux R extra. 

Ccrasin. — Rouge B. 

Ponceau 2G. — Brilliant ponceau GG, ponceau JJ. 

Fuchsin S. — Acid magenta, rubin S, fuchsin acide (free from arsenic). 

Archil Substitute. — Naphthion red. 

Orange I. — Orange No. i, naphtholorange, alpha-naphtholorange, 
tropoeolin OOO No. i. 

Congo red. 

Azorubin S. — Azorubin, azorubin A, azoacidrubin, fast red C, car- 
moisin, brilliant carmoisin O, rouge rubin A. 

Fast Red D. — Fast red EB, fast red NS, amaranth, azoacidrubin 2B, 
Bordeaux DH, Bordeaux S, naphthol red S, naphthol red O, Victoria 
ruby, wool red (extra), oenanthinin. 

Fast Red. — Fast red E, fast red S, acid carmoisin S. 

Ponceau 4GB. — Crocein orange, brilliant orange G, orange GRX, 
pyrotin orange, orange ENL. 

Fuchsin. 

Melanitrazoiin. 

Yellow and Orange CdioTS.—Annatto. 

Saflron. 

Safflower. 

Turmeric. 

Naphthol Yellow S. — Citronin A, sulphur yellow S, jaune acide, 
jaune acide C, anilin yellow, succinine, saffron-yellow, solid yellow, 
acid yellow S. 

Brilliant Yellow. — (Sch.) 

Ponceau 4GB. — Crocein orange, brilliant orange G, orange GRX, 
pyrotin orange, orange ENL. 

Fast Yellow. — Fast yellow G, fast yellow (greenish), fast yellow S, 
acid yellow, new yellow L. 

Fast Yellow R. — Fast yellow, yellow W. 

Azarin S. 

Orange I. — Orange No. i, naphtholorange, alpha-naphtholorange, 
tropasolin OOO No. i. 

Orange. — Orange GT, orange RN, brilliant orange O, orange N. 

Mixtures of harmless red and yellow colors. 

Green Colors. — Spinach green. 

Chinese green. 

Malachite Green. — Alalachite green B, bcnzaldehyde green, new Vic- 



634 FOOD INSPECTION ^ND ANALYSIS. 

toria green, new green, solid green crystals, solid green O, diamond green, 
bitter amond oil green, fast green. 

Dinitrosoresorcin. — Solid green O in paste, dark green, chlorine green, 
Russia green, Alsace green, fast green, resorcinol green. 

Mixtures of harmless blue and yellow colors. 

Blue Colors. — Indigo. 

Litmus. 

Archil blue. 

Gentian Blue 6B. — Spirit blue, spirit blue FCS, opal blue, blue 
lumiere, Hessian blue, light blue. 

Couplers Blue. — Fast blue R and B, solid blue RR and B, indigin DF, 
indulin (soluble in alcohol), indophenin extra, blue CB (soluble in alcohol), 
nigrosin (soluble in alcohol), noir CNN. 

In General such blues as are derived from triphenylrosanihn or from 
diphenylamin. 

Violet Colors. — Paris Violet. — Methyl violet B and 2B, methyl 
violet V3, pyoktanin coeruleum, malbery blue. 

Wool black. 

Naphthol black P. 

Azoblue. 

Mauvein. — Rosolan, violet paste, chrome violet, anilin violet, anilin 
purple, Perkins violet, indisin, phenamin, purpurin, tyralin, tyrian purple, 
lydin. 

Brown Colors. — Caramel. 

Licorice. 

Chrysamin R. 

Use of Colors in Confectionery. — Regarding the choice of colors for 
use in confectionery and precautions to be observed in their use, the 
Confectioners' Association has offered the following considerations: 

First. That coal-tar colors are specially adapted to the wants of 
confectioners on account of their brilliancy, permanency, and high color- 
ing power, by reason of which last-named quality only infinitesimal 
amounts of color need be or can be used to give the desired effects. 

Second. That there is no evidence to show that any poisonous or 
hurtful colorings have in recent years been found in confectionery. 
Reports of deaths from poisoned candy are only too frequently made, 
but no autopsy has ever been published confirming them. 

Third. That while the exceedingly small proportions of color used 
in confectionery constitute a practical safeguard to the public health, con- 



ARTIFICIAL FOOD COLORS. 635 

fectioners are in duty bound to provide against all possible contingencies 
of harm, by using the utmost care in obtaining absolutely non-poisonous 
colors, buying only from color-dealers of established reputation and 
unquestioned responsibility, whose colors are tested at frequent intervals, 
and are vouched for by competent chemists. 

Confectioners should require that a guarantee be put upon each 
package of color, stating not only that the contents are non-poisonous, 
but also that they will not in any way interfere with digestion or injure 
health. 

Fourth. Any illegitimate use of coloring matter in confectionery as 
a substitute for chocolate or any other material or ingredient, or for the 
purpose of adding bulk or increasing the weight of the confectionery 
in which it is incorporated, should not be permitted or countenanced. 
Both the letter and the spirit of these laws should clearly prevent the 
illegitimate use of coal-tar colors or of earth colors, such, for example, as 
chocolate-brown, coconole brown, or chocolatina. 

Fi]th. That color-dealers furnishing colors to confectioners should 
publish printed lists of their colors under the various names and titles 
by which they are known and offered for sale, accompanying such lists 
with ample certifications by competent chemists to their purity and suit- 
ableness for coloring confectionery and other articles of food. They 
should also attach to each package or other container of color a guar- 
antee that it does not contain anything injurious to health. 

VEGETABLE COLORS. 

These with a few mineral pigments and cochineal were formerly 
almost exclusively used for coloring food products, and are still used 
to some extent. 

Most of the vegetable colors, according to L. Robin,* react with 
ammonia to form a coloration, usually passing from violet to blue, then 
to a brownish green, when the ammonia is added little by little in excess 
to the color in solution. If by the addition of ammonia to a solution 
of an unknown color the green coloration does not result, the presence 
may be suspected of orchil or cudbear, logwood, cochineal, or a coal-tar 
dye. 

The following vegetable colors are occasionally found in food, with 
some of the reactions in aqueous solution, as given by Robin: 

* Girard et Dupre, .Analyse des Matiercs Alimentaires, p. 579. 



636 



FOOD INSPECTION AND ANALYSIS. 
RED COLORS. 



Nature of Color. 


Ammonia. 


Alum and Sodium Carbonate 
20% Solution. 


Mixture of 
Aluminum 
Acetate and 




Lake. 


Filtrate from 


Sodium 
Carbonate. 


Bilberry (whor- 
tleberry) 

Beet 


Dull greenish 

Muddy yellow, 
brown, or rose- 
red 
Deep green 
Red tinged with 
violet 

Currant-red 
Bluish green 

Yellow-brown to 
greenish 
Yellowish green 

Lilac 
Light green 


Greenish blue, 
rose-colored on 
edges 

Dull green or rose 

Greenish blue 
Blue tinged with 
violet 

Rose 
Rose tinged 

Gray to lilac 

White or rose vio- 
let 

Violet 

Blue tinged with 
violet 




Bluish violet 




Garnet 


Black currant. . . 
Logwood 

Brazil wood 

Raspberry 

Currant 

Blackberry 

Phytolacca 

Elderberry 


Bottle-green 


Violet-blue 
Tinged with violet 

Lilac to wine color 
Lilac tinged with 
violet 
Red-maroon 

Dull violet 

Clear violet, pass- 
ing to yellow 
with ammonia 

Violet, quickly 
passing to blue 
with acetate of 
copper 


Rose tinged 
Bluish green 

Dull maroon to 
bottle-green 
Bluish 







YELLOW COLORS. 



Nature of Color. 


Ammonia. 


Hydrochloric Acid. 


Alum and Carbonate 

of Soda 20% 

Solution. 

Lake. 


Persian berries 

Old fustic 


Yellow-red 

Very bright yellow 
Becomes clearer 

Yellowish red 
Brown-red 


Precipitate yellow- 
brown 
Yellow-orange 
Bright yellow pre- 
cipitate 
Becomes yellower 
Crimson precipitate 


Orange 
Orange 


Quercitron bark 

Young fustic 


Yellow-red tending to 

green 

Bright yellow 

Bright yellow 







Additional yellow vegetable colors sometimes used in foods are the 
following, taken from a table of Leed's,* showing reactions given by 
treating a few drops of an alcoholic solution of the color with an equal 
volume of the reagent. 

Most of these vegetable colors do not directly dye wool or silk a fast 
color, but as a rule require the use of a mordant. Many of these colors 
may be fixed on cotton (previously mordanted by boiling in a solution 

* Analyst, 12, 150. 



ARTIFiCI/IL FOOD COLORS. 



637 



REACTIONS OF COLORING MATTERS. 



Coloring 


Concentrated 


Concentrated 


H^SOi-f HNO3. 


Concentrated 


Matter. 


HjSOi. 


HNO3. 




HCI. 


Annatto 


Indigo-blue, chang- 


Blue, becoming 


Same 


No change, or only 




ing to violet 


colorless on 
standing 




sUght dirty yel- 
low and brown 


Turmeric. . . 


Pure violet 


Violet 


Violet 


Violet, changing to 
original color on 
evaporation of 
HCI 


Saffron 


Violet to cobalt 


Light blue, chang- 


Same 


Yellow, changing 




blue, changing to 


ing to light red- 




to dirty yellow 




reddish brown 


dish brown 






Carrot 


Umber brown 


Decolorized 


Same with NOj 
fumes and odor 
of burnt sugar 


No change 


Marigold 


Dark olive-green, 


Blue, changing in- 


Green 


Green to yellowish 




permanent 


stantly to dirty 
yellow-green 




green 


Safflower. . . 


Light brown 


Partially decolor- 
ized 


Decolorized 


No change 



of aluminum acetate or potassium bichromate) by boiling the mordanted 
fibers in a bath of the colored solution, rendered acid by acetic acid. The 
dyed fibers are then examined by reagents, as in tables given on pages 
652-659. 

Special Tests for Vegetable Colors.— OrcA// and Cudbear, both 

derived from lichens, dye wool red in acid bath. The colored fiber, 
in the case of cudbear, is turned blue by treatment with ammonia. For 
reactions of orchil on the fiber see table, page 654. Robin's test for orchil 
in aqueous solution consists in shaking it with ether, which, if orchil is 
present, is colored yellow. On treatment of the ether with ammonia, 
the yellow color is changed to blue, and, by adding acetic acid, goes over 
to a reddish violet. 

Logwood, according to Robin, in aqueous solution colors ether yellow, 
and on treating the ether with ammonia the color becomes red or faintly 
violet. Potassium bichromate gives a violet coloration, mingled with 
greenish yellow. If cotton is first mordanted by boiling with aluminum 
acetate, it is dyed violet when boiled in a solution of logwood. 

Turmeric is best extracted from a dry residue with alcohol, which it 
colors 3'ellow. The color is transferred to a piece of filter-paper by soak- 
ing the paper in the alcoholic tincture, the paper is dried and dipped 
in a dilute solution of boric acid or borax slightly acidulated with hydro- 
chloric acid. On again drying the paper, it will be of a cherry-red color 
if turmeric is present, and when touched with a drop of dilute alkali will 
turn dark olive. 



638 FOOD INSPECTION /IND AN/I LYSIS. 

Caramel. — Care should be taken in testing for caramel not to subject 
the sample to long-continued heating, even on the water-bath. Indeed 
caramel is sometimes developed spontaneously in saccharine food prod- 
ucts during their process of manufacture when heat is used, by the charring 
cf the sugar. If solutions are to be concentrated or brought to dryness 
before testing for caramel, this should be done in a vacuum desiccator 
over sulphuric acid, or at a temperature not exceeding 70°. For detection 
of caramel in milk, vinegar, and liquors, special tests are given elsewhere. 

Fradiss Test.* — The dried residue of the sample to be tested is 
extracted with warm, pure methyl alcohol, which, if caramel be present, 
is colored brown. Filter, and to the fdtrate add amyl alcohol or chloro- 
form. In presence of caramel, a brown tlocculent precipitate is formed, 
which slowly settles to the bottom of the tube. 

Indigo in aqueous solution turns green with ammonia. On boiling, 
the solution becomes bright blue. Indigo in neutral or acid solution 
dyes wool or silk. 

MINERAL PIGMENTS. 

Evidence of the presence of these pigments is usually best looked for 
in the ash of the suspected sample. In some cases the color may be 
extracted from the dried residue by water, alkali, or alcohol. 

Prussian Blue. — This pigment is insoluble in water. It is decom- 
posed and decolorized by treatment with potassium hydroxide. If the 
filtered alkaline solution of the coloring matter be treated with hydro- 
chloric acid and ferric chloride, a precipitate of the original Prussian 
blue will be produced. For reactions on the fiber see table, page 658. 

Ultramarine Blue is decolorized by hydrochloric acid. Treatment of 
ultramarine with this acid also causes the evolution of hydrogen sulphide, 
which blackens filter-paper moistened with lead acetate. For the recog- 
nition of ultramarine in sugar see page 498. For its detection on the 
fiber see table, page 658. 

Chromate of Lead has never been used to any extent in food products 
with the exception of confectionery. For its detection, see page 519. 

Cochineal. — This dyestuff, of animal origin, is used in ketchups, 
cordials, confections, and other food products. Robin's test for coch- 
ineal is as follows: The aqueous solution is acidulated with hydrochloric 
acid, and shaken out in a separatory funnel with amyl alcohol. Cochineal 

* Oestr. ungar. Zeits. Zucker. Ind., 1899, 28, 229-231; Abs. Zeits. f. Unters. Nahr. u, 
Genuss., 2, iSgg, 881. 



ARTIFICIAL FOOD COLORS. 639 

imparts to this solvent a yellowish color, the depth depending on the 
amount present. The separated amyl alcohol is washed with water 
till neutral, and divided into two portions. To one of these a little water 
is added, and then drop by drop a solution of uranium acetate, shaking 
each time a drop is added. In presence of cochineal the water is colored 
a very characteristic emerald-green color. To the other portion ammonia 
is added. If cochineal has been used, a violet coloration is produced. 
These reactions are very delicate. 

COAL-TAR COLORS. 

So many of the coal-tar dyes are adapted for use in food that it would 
be impossible to even name them all, especially in view of the fact that 
new colors are from time to time being added to the list. No attempt 
will be made in the present work to give the nature and composition of 
the dyes named, as such descriptions would lead beyond its scope. For 
detailed information along this line the reader is directed to the references 
on page 660, and especially to the works of Schultz and Julius, Benedic. 
and Knecht, Weyl, etc. 

About 2000 separate coal-tar dyes are at present on the marke'.. 
Various classifications of these colors are attempted, based on (i), their 
origin, as anilin dyes, naphthalin dyes, anthracene dyes, etc.; (2), their 
chemical composition, as nitro, nilroso, azo, diazo, and other compounds; 
(3), their solubility in water and o:her solvents; and (4), their mode 
of application to the fiber, as basic dyes, acid dyes, direct cotton dyes, mor- 
dant dyes, etc. 

These d3'es are sold in the form of powder, and are readily made 
into solutions for food colors in the case of the water-soluble varieties, 
and into pastes in the case of the insoluble forms. Most of the coal-tar 
colors employed in foods are naturally of the soluble variety, especially 
such as are found in jellies, jams, fruit products, canned foods, ketchups, 
beverages, and milk. Pastes made from insoluble dyes are adapted 
mainly for exterior coatings of hard substances such as candies. Colors 
in the dry form are to be looked for in such spices as cayenne, mustard, 
and mace, but a commoner method of coloring these spices high in oil 
is to mix with them a solution of the color in oil (usually cottonseed). 
Oil solutions of coal-tar dyes are also employed for coloring butter and 
oleomargarine. 

The chief concern of the food analyst, as regards artificial color is 



640 FOOD INSPECTION AND ANALYSIS. 

its recognition in food products. Coal tar dyes may usually be iden- 
tified as such, but it is not always possible to name the particular 
individual dye or combination of dyes employed, even though the class 
to which they belong may be determined. One reason for this is that 
not infrequently mixtures of two or more colors are employed. 

Detection of Coal-tar Colors in Foods. — There are various 

methods for the separation of coloring matters from food products, and 
these may be divided into three general classes: First, dying silk or wool 
with the color by boiling the fiber in a solution of the sample to be 
examined; second, extracting the color from a solution of the sample 
by the use of an immiscible solvent; and third, extracting the color from 
the dried residue of the sample by means of a suitable solvent. Of these 
the method of dying wool lends itself most readily to the analyst's use, 
by reason of its simplicity, and from the fact that almost without excep- 
tion coal-tar dyes adaptable for food colors are substantive dyes, being 
readily taken up by wool. 

Basic and Acid Dyes. — The soluble coal-tar dyes are either basic 
or acid. Basic dyes are precipitated from their aqueous solution by 
tannin. .-Vcid dyes are not so precipitated. Theoretically, all the basic 
colors are taken up by wool from a faintly alkaline or neutral bath, while 
the acid colors are left in solution. Thus if a dilute solution of the color 
be made faintly alkaline with ammonia and boiled with the wool, only 
basic colors will be taken up. If both acid and basic dyes are present 
in the same solution, the basic color should first be exhausted by the 
use of fresh pieces of wool in the ammoniacal solution, till they no longer 
take out color, after which the solution should be made slightly acid 
with hydrocliloric acid and again boiled with wool, which under these 
conditions takes out any acid colors. Comparatively few basic colors 
are employed in foods. Basic colors can be removed from the fiber 
by boiling with 5% acetic acid. Acid colors are removed therefrom by 
boiling with 5% ammonia. Having dissolved the dye from the fiber 
by the appropriate solvent as above, the decolorized fiber may be removed, 
and the solution evaporated to dryness on the water-bath. The residue 
consists chiefly of the dyestuff, and may be put through various reactions 
for identification according to Rota's scheme, page 644. 

Methods of Dyeing Wool from Food Products. — The wool employed 
should be white worsted, or strips of white cloth, such as nun's veiling 
or albatross cloth. Care should be taken that the color is pure white 
and not the more common cream white. The woolen material should 



ARTIFICIAL FOOD COLORS. 641 

be freed from grease by boiling first in very dilute soda solution and 
finally in water. Strips of the woolen cloth, or pieces of the worsted thus 
previously cleansed, are boiled in diluted filtered solutions of jams, jellies, 
ketchup, fruit and vegetable products, and similar food preparations, or 
in solutions of candy colors, or in wines, the clear solution of the sample 
to be tested being slightly acidified with hydrochloric acid. 

Arata * recommends boiling the wool in a dilute solution of the food 
material to which potassium bisulphate has been added, using 10 cc. 
of a 10% solution of the bisulphate to 100 cc. of the solution to be tested. 
If the color solution is neutral, the wool should first be boiled in this 
before acidifying, to separate out any basic dyes. The dyed wool, after 
removal from the solution, is boiled first in water, and afterwards prefer- 
ably in an alkali-free soap solution. It is then washed and dried. The 
dried fiber may then be subjected to the various reactions given in the 
table, pp. 652-659, for recognition of the dye, this method of identifying 
colors by means of reactions on the dyed fiber being one of the most con- 
venient. 

A few of the vegetable colors as well as cochineal will dye 
wool directly, and these may be identified by reactions given in the table 
with the coal-tar dyes. Other vegetable colors, and the natural colors 
of fruits nearly always give a slight dull coloration or stain to the wool, 
but this is not, as a rule, to be mistaken for the vivid hues of the coal- 
tar dyes. Moreover most of the vegetable colors on the fiber turn green 
when treated with ammonia. Care should be taken to thoroughly wash 
the wool after the dyeing, so that colored particles simply held thereon 
mechanically may be removed. 

Sostegni and Carpentieri ■f recommend a method of double dyeing, 
applicable when acid dyes are employed. The method consists in 
first boiling the wool in a dilute acid solution of the food sample as 
above described, after which the fiber is removed and boiled, first in 
very dilute hydrochloric acid solution, and then in water, till free from 
acid. The color is then dissolved from the fiber by boiling the latter 
in a weak ammoniacal solution, some of the colors being more readily 
dissolved than others. The fiber is then removed from the solution, 
the latter is acidified with hydrochloric acid, and the color fixed on a 
fresh piece of wool by boiling therein. The second dyeing fi.xes only coal- 
tar colors on the fiber, so that there is no fear of mistaking vegetable 

* Ztsch. anal. Chem., 28 (1S89), 639. 
fibid., 33 (1896), 397. 



642 FOOD INSPECTION AND ANALYSIS. 

colors therefor. Any color left on the first fiber, after treatment with 
ammonia, is probably due to the natural vegetable color of the sample, 
and is usually no more than a dull stain. 

Vegetable Colors on Wool. — In case no color is directly fixed on the 
fiber by boiling wool in a solution of the sample, either neutral or acid, 
absence of coal-tar colors may be assumed. In this case it is sometimes 
advisable to boil strips of previously mordanted white cotton in an acid 
solution of the sample, to remove certain vegetable colors for purposes 
of testing on the fiber. The cotton is mordanted by boiling in a dilute 
(5%) solution of potassium bichromate. 

Extraction of Colors from their Solution by Immiscible Solvents. — 
Methods based on this principle are in use in the municipal laboratory 
at Paris.* Sangle-Ferriere uses the following method: 50 cc. of the 
wine or solution to be tested for color are rendered slightly alkaline by 
ammonia, and cautiously shaken with about 15 cc. of amyl alcohol. If 
acid dyes are present, they will be dissolved, and will impart to the amyl 
alcohol a distinct color.f Basic dyes also are dissolved, but when they 
are present the amyl alcohol solution is colorless. Remove the amyl 
alcohol by means of a separatory funnel, wash with water, and finally, 
if the alcohol is colored, dilute with about an equal volume of distilled 
water and evaporate on the water-bath with a piece of white wool. The 
wool should be kept in the solution till the odor of the amyl alcohol has 
disappeared, and, if not then colored, for a short time longer, as with 
some colors the wool will dye more readily in the aqueous solution than 
in the amyl alcohol. Remove the wool, and evaporate the solution to 
dryness. Test for color in the dried residue, and on the fiber also. 

Orchil, like the acid colors, is extracted by, and imparts a coloration 
to the amyl alcohol under the above conditions, the color being a light 
violet. It will not, however, dye the fiber. 

If the amyl alcohol extract after separation, washing, and filtering 
is colorless, acidify with acetic acid; if a basic color is present, it will 
be indicated by a coloration at this stage; if there is no coloration on 
the addition of acetic acid, no basic color is present excepting fuchsin, 
which is separately tested for. In case a basic dye is indicated, add dis- 
tilled water and evaporate with wool as before. Test the dried residue 
with pure concentrated sulphuric acid. 

* Girard et Dupre, Analyse des Matiers Alimentaires, pp. 167, 581 

t Acid fuchsin forms an exception to this rule by dissolving colorless like basic dyes. 
A special test is, however, given for it, p. 644. 



ARTlFlCl/fL FOOD COLORS. 643 

Fuchsin is indicated by a yellow-brown color with sulphuric acid, 
which by dilution with water becomes rose; sajranin, by a green color 
becoming first blue, then red, when diluted with water, and magdala 
red by a dark blue color, turning red on the addition of water. 

Basic colors are also extracted readily, according to Robin, by making 
the solution to be tested alkaline with sodium hydroxide, and shaking 
with acetic ether. The solvent is removed, washed, and evaporated 
with wool (on which the tests are to be made), or the evaporation is 
carried to dryness and the tests made on the residue. 

Many coal-tar colors are extracted by amyl alcohol in acid solution, 
but some of the natural fruit colors are also dissolved under these con- 
ditions. The coal-tar dyes thus dissolved will, however, dye wool and 
the fruit colors will not. Fruit colors are not extracted from acid or 
alkaline solution by ether, nor from alkaline solution by amyl alcohol. 

Robin's method for ascertaining whether acid colors are present 
consists in adding to the liquid to be tested an excess of calcined magnesia, 
and a little 20% mercuric acetate solution, the mixture being boiled and 
filtered. If the filtrate is colored, or if by the addition of acetic acid 
to the colorless filtrate a color is developed, a coal-tar dye is indicated. 

Separation of Acid and Basic Colors with Ether.* — Acid and basic 
colors may be separated from their dilute aqueous solution, according 
to Rota, by means of ether as follows: To 100 cc. of the solution add 
I cc. of 20% potassium hydroxide and shake in a separatory funnel with 
several portions of ether. Basic dyes are dissolved by the ether, leaving 
behind as a rule the acid colors. f Wash the ether extract with faintly 
alkaline water, and shake out with 5% acetic acid. Some colors remain 
in the ether, others are dissolved in the acid. Separate the two solvents, 
and evaporate each to dryness on the water-bath. 

The acid colors left in the slightly alkaline, aqueous solution after 
removal of the basic colors by ether as above, may, if desired, be separated 
into several groups by successive extraction, as follows: first slightly 
acidulate with acetic acid and extract with ether, then acidify with hydro- 
chloric acid and again extract, and finally examine the residual solution 
for colors that are insoluble in ether. Thus erythrosin and eosin are 
soluble in ether when shaken with their aqueous solution made acid with 
hydrochloric acid, while acid fuchsin is insoluble. 

* Analyst, 24, p. 45. 

t A few acid dyes are exceptional in being soluble in ether with alkali, as for example, 
quinolin yellow and the sudans. 



044 FOOD INSPECTION AND ANALYSIS. 

Separation of Colors from Dried Food Residues by Solvents. — This 
method is rarely employed, excepting in the case of colors insoluble in 
water, but soluble in ether or alcohol. The dried pulp of canned veget- 
ables, ketchups, etc., may be acidified with hydrochloric acid, and the 
color extracted therefrom directly wi'.h alcohol. In this case however, 
there is no obvious advantage over the previous methods of dyeing the 
fiber directly in the acid solution of the sample. 

Girard's Tests for Acid Fuchsin.* — Add 2 cc. of 5% potassium 
hydroxide to 10 cc. of the wine or other solution to be tested, or enough 
of the alkali to neutralize the acid. Then add 4 cc. of 10% acetate of 
mercury and filter. The filtrate should be alkaline and colorless. If 
the solution remains uncolored after acidifying with dilute sulphuric 
acid, no acid fuchsin is present. If, however, there is produced a red 
to violet coloration, and no other coal-tar colors have been found by the 
amyl alcohol extraction, the presence of acid fuchsin is shown. 

Bellier's Test for Acid Fuchsin. — Presence of acid fuchsin is indicated 
by adding to 20 cc. of wine or other solution to be tested about 4 grams 
of freshly precipitated yellow oxide of mercury, boiling and filtering. 
The filtrate, if acid fuchsin is present, is colored red, tinged with violet. 

According to Blarez, all red coal-tar colors, wilh the exception of acid 
fuchsin, and all red vegetable colors are completely decolorized by acidu- 
lating their aqueous solution with tartaric acid, and digesting with dioxide 
of lead.f 

CLASSIFICATION AND IDENTIFICATION OF COAL-TAR DYES. 

Various excellent schemes have been prepared for identifying unknown 
colors by their characteristic reactions, first grouping them into classes, 
and finally ascertaining the particular color itself. Of these may be 
mentioned the tabular schemes of Witt, J Weingartner,§ Green,||' Mar- 
tinon,1[ and Rota.** 

Rota's Scheme is one of the latest, and on some accounts the best, 
being based on the relation between the color and the composition of 

* Analyse der Substances Alimentaires, p. 169. 

t Allen, Commercial Org. Analysis, vol. Ill, p. 283. 

% Zeits. anal. Chem., 1887, 26, p. 100; Analyst, 11, p. iii. 

§ Jour. See. Dyers, etc., Ill, p. 67. 

11 Jour. Soc. Chem. Ind., 12, No. i. 

If Jour. Soc. Dyers, 3, p. 124. 

** Chem. Zeit., 1898, pp. 437-442; Anal., 24, p. 41, 



/tRTIFICIAL FOOD COLORS. 



645 



the dyes. The colors are divided into two main groups, according to 
whether or not they are reducible by stannous chloride. These two 
groups are each further subdivided into two classes, the reducible colors 
being classed according to whether the color remains unchanged, or is 
restored by treatment with ferric chloride, and the non-reducible colors 
according to their action with potassium hydroxide. 

The tests are carried out on a dilute aqueous or alcoholic solution 
of the coloring matter, the strength being about i in 10,000. Treat 
about 5 cc. of this solution with 4 or 5 drops of concentrated hydrochloric 
acid and about as much stannous chloride in a test-tube, shake the mix- 
ture, and heat if necessary to boiling. With some colors the process of 
decolorization is a slow one, especially if the solution is too concentrated, 
and it is well to repeat the experiment, if in doubt, diluting the original 
sample still further with water. Tin in solution in concentrated hydro- 
chloric acid may be employed instead of stannous chloride, if desired. 

Here, as in all cases of color testing, it is well to make comparative 
tests with known colors. 

CLASSIFICATION OF ORGANIC COLORING MATTERS. 
[A portion of the aqueous or alcoholic solution is treated with HCl and SnClj.] 



Complete decolorization. Reducible coloring 
matters. Colorless solution is treated with 
Fe^Clj, or shaken with exposure to air. 



The color changed no further than with HCl 
alone. Nonreducible colors. A part of 
original solution is mi.xed with 20% KOH 
and warmed. 



The liquid remains 
unchanged. Color- 
ing matters not re- 
o.xidizable. 



Cl.\ss I. 

Nitro, nitroso, and azo 
colors, including 
oxyazo and hydrazo 
colors. 

Picric acid, naphthol 
yellow, ponceau, 
Bordeaux, and 
Congo red. 



The original color re- 
stored. Reoxidiz- 
able coloring mat- 
ters. 



Class II. 

Indogenide and imido- 
quinone coloring 
matters, methylene 
blue, safranin, in- 
digo carmine. 



Decolorization, or a 
precipitate. Imido- 
carbo-quinone color- 
ing matters. 

Class III. 

Amido-derivatives of 
di and triphenyl 
methane, a u r a - 
m ins, acridi ns, 
quinolins, and 
color derivatives of 
thio benzenil. 

Fuchsin, rosaniUn, 
auramin. 



No preci p i t a t i o n. 
Liquid becomes 
more colored. Oxy- 
carbo-quinone col- 
oring matters. 

Class IV. 

Nonamide diphenyl 
methane, o.xy-ke- 
tone, and most of 
natural organic col- 
oring matters. 

Eosins, aurin, aUz- 
arin. 



646 FOOD INSPECTION AND /IN A LYSIS. 



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ARTIFICIAL FOOD COLORS. 647 




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650 FOOD INSPECTION AND ANALYSIS. 

Direct Identification of Colors. — In identifying the colors commonly 
used in food, it is rarely necessar}' to carr}^ out such involved processes 
of analyses as are rendered necessary by Rota's scheme. It is frequently 
possible to ascertain the color or group of colors present by making direct 
tests with various reagents, either on the dyed fiber, or on the drj' color- 
ing matter, or in a solution containing it. 

Many tables for this pur])ose are prepared, but they are never com- 
plete by reason of the many nevir dyestuffs constantly introduced. Such 
tables are to be found in Allen's "Commercial Organic Analysis," and 
in Schiiltz and Julius's "Systematic Survey of the Coal Tar Colors." 
While it is true that the limitation of the dyes suitable for purposes of 
food coloring imposes a somewhat lighter task on the food analyst than 
that of the chemist who has to deal with all varieties of commercial colors, 
yet it is obviously impossible to make a complete list covering even the 
restricted field of food colors. Doubtless there are colors long well 
known that would serve admirably for this purpose, but have never yet 
been tried. 

Mainly from such sources as the above comprehensive tables of colors 
and their reactions, the writer has compiled the table on pp. 652-659, 
taking as a basis the scheme of Allen.* This table includes about fifty 
selected coloring matters, which are adapted for, and have been 
found in, foods by various analysts, as listed in state and government 
reports, as well as in laws of various countries dealing with food 
colors. This table will at least contain the colors most commonly met 
with, and will nearly always serve, if not to identify the exact dye, to 
aid in classifying it. In case the analyst wishes to identify the color, 
he should be provided, for standards, with as complete a collection of 
known purity dyestuffs as possible covering the colors he is likely to 
meet with in foods, and should make comparative tests, if the slightest 
doubt exists. If the unknown color is apparently not found in the following 
table, and the more exhaustive tables are unavailable, it is still possible 
to locate the dye, by making similar tests on other standard colors sug- 
gested by the behavior of the unknown color, and carefully comparing 
them. 

Most difficulty is encountered when the coloring matters are mixtures 
instead of simple dyes. In this case it may be necessary to resort to frac- 
tional extraction by ether, as suggested by Rota (p. 643), in order to 
separate the colors. 

* Commercial Organic Analysis, Vol. Ill, pt. i, 3d ed., p. 530 et seq. 



/IRTIFICIAL FOOD COLORS. 651 

Reagents. — In applying tests on the fiber, the reagents commonly used 
are as follows: Concentrated hydrochloric acid, concentrated sulphuric 
acid, sodium hydroxide (10% solution), strong ammonia (28%), a hydro- 
chloric acid solution of stannous chloride, and concentrated nitric acid. 
The tests should be made on pieces of the fiber in small porcelain evapo- 
rating-dishes, which more readily than test-tubes show exact shades of 
color. In cases of suspected fluorescence, test-tubes should be used. 
Nitric acid is conveniently applied by a glass rod to the fiber. The 
stannous chloride should first be allowed to act in the cold. If no change 
occurs, gentle heat should then be applied, and finally boiling. 



6s« 



FOOD INSPECTION AND /INA LYSIS. 



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654 



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ARTIFICIAL FOOD COLORS. 



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FOOD INSPECTION MND /tNALYSIS. 



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o 
u 

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t— I 

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Blue 
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Decolorized 

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Yellow 

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1 

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Violet 

Violet 
Violet 

Indigo 
Blue 


Blue 
Green 

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a 


Green metallic 

powder 
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1^ 


Bronze powder 

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powder 

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powder 


; 

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Colors. 

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ARTIFICIAL FOOD COLORS. 



659 



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66o FOOD INSPECTION AND ANALYSIS. 

REFERENCES OX COLORS. 

Arata, p. N. (Specielle analytische INIethoden.) Zeits. anal. Chem., 28, 639. 
Bellier, J. Detection of Artificial Coloring Matters in Wine. Ann. de Chim. Anal., 

5, 1900, 407; Abs. Analyst, 26, 1901, 42. 
Benedikt, R., and Knecht, E. The Chemistry of the Coal-tar Colors. London, 1889. 
DoMMERGUE, G. Detection of Colors on Dyed Wool. Monit. Sclent., ^t„ 25; Abs. 

Jour. See. Chem. Ind., 8, 216. 
FoL, F. Testing of Dyestuffs. Jour. Chem. Soc, 28, 1875, 193. 
GiRARD, P. Couleurs Employes dans les Matiferes Alimentaires. Analyse des Matieres 

Alimentaires (Girard et Dupre), p. 689. Paris, 1894. 
Green, A. G. On the Qualitative Analysis of Coal Tar Coloring Matters. Jour. 

Soc. Chem. Ind., 12, 1893, p. 3. 
Leeds, A. R. Tabellarische Uebersicht der kiinstlichen organischen Farbstoffe. 

Berlin, 1894. 
Martinon, B. Jour. Soc. Dyers, 3, 124. 

NiETZKi, R. Chemie der organischen FarbstofTe. Berlin, 1901. 
POSETTO, G. Composition of Vegetable Coloring Matters for Use in Confectionery. 

Zeits. Nahr. Unters. u. Hygiene, 9, 1895, 150. 
Rawson, C, Knecht, E., and Lowenthal, R. A Manual of Dyeing. London, 1893. 
Rawson, Gardner, and Laycock. A Dictionary of Dyes, Mordants, etc. 1890. 
Reichelmann and Leuscher. Detection of Coal Tar Colors in Pastry, Cakes, Fruit 

Products, etc. Zeit. fiiroffentl. Chem., 8, 1902, 204; Abs. Analyst, 27, 1902, 276. 
Rota, A. R. A Method of Analyzing Natural and Artificial Organic Coloring Matters. 

Analyst, 24 (1899), 41. From Chem. Zeit., 1898, 437. 
ScHULTZ, G., u. Julius, P. Taballarische Uebersicht der kiinstlichen organischen 
Farbstoffe. 1897. 

Translated by Green, A. G. A Systematic Survey of the Organic Coloring 

Matters. 1894. 
Spaeth, E. Foreign Coloring Matters in Fruit Juices. Zeits. fiir Unters. der Nahr. u. 

Genuss., 2, 1899, 633. 
SosTEGNi, L., and Carpentieri, F. (Specielle analytische Methoden.) Zeits. anal. 

Chem., 35 (1896), 397. 
Spiller, J. Identification of the Coal Tar Colors. Analyst, 6, 1881, 23. 
Tassart, C. L. Des Matieres colorantes. Paris, 1890. 
ToLMAN, L. ]\L Coloring Matter in Food. U. S. Dept.' of Agric, Bur. of Chem., 

Bui. 65, p. III. 
Weber, H. A. Effect of Coal Tar Colors on Digestion. .\m. Chem. Jour., 8, 1896, 

1092. 
Weingartner. Eine Anleitung zur Untersuchung der im Handel vorkommenden 

kiinstlichen Farbstoffe. Zeits. anal. Chem., 27 (1888), 232. 
Weyl, T. Translated by Leffmann, H. The Sanitary Relations of the Coal Tar 

Colors. Philadelphia, 1892. 
WiNTON, A. L. The Use of Coal Tar Dyes in Food. Conn. Agric. Exp. Sta. Rep., 1901, 

p. 179. 
Witt, O. N. Versuch. einer qualitat'ven Analyse der im Handel vorkommenden 

Farbstoffe. Zeits. anal. Chem., 26 (1887), 100. 



CHAPTER XVII. 
FOOD PRESERVATIVES. 

Preservation of Food. — Various processes have from ancient times 
been known and used for arresting the fermentative changes which food 
products in their natural state undergo on long standing. These proc- 
esses include pickling with vinegar, drying, smoking, salting, preserving 
with sugar, and finally in the employment of heat in sterilizing and pas- 
teurizing, and of low temperature as in cold storage. All of them are 
still in use, and are universally regarded as unobjectionable. In addi- 
tion to these old and well-kno^vn methods of food preservation is the 
comparatively modern practice of arresting fermentation by the use of 
such antiseptic chemical agents as formaldehyde, beta-naphthol, boric, 
salicylic, benzoic, and sulphurous acids or salts of these acids, etc., in 
regard to the wholesomeness of which there is considerable difference 
of opinion. These substances depend for their efficiency on the more 
or less complete inhibition of bacterial growth. Nearly all exert a power- 
ful antiseptic influence, to such an extent that to accomplish their object 
only small quantities need be used in food. 

Apart from their toxic effects, a marked difference naturally exists 
between the employment of such substances as salt, sugar, and vinegar 
for food preservation, all of which are in themselves foods, and in the 
use of chemical agents that have no food value. The advocates of 
the use of chemical antiseptics claim that there are no authentic instances 
on record of injury from the use of such small quantities of these sub- 
stances as are necessary to arrest decay, while there are many cases of 
injury arising from the use of foods which, while apparently wholesome, 
have undergone such fermentation as to develop ptomaines or other 
harmful toxins, and that because antiseptics prevent such spoiling of the 
food, their use is decidedly beneficial; that there is, besides, no more 
reason why a prejudice should exist against the employment of these 

66i 



<^6t. FOOD INSPECTION AND ANALYSIS. 

newer chemicals than against saltpeter, which has long been used in the 
coming of meat, or against the cresols and phenols left as a product of 
smoking. 

The opponents to their use assert, that the addition to food of 
such antiseptic substances as prevent its decay also serves to retard 
the digestive processes when the food is eaten; that many of these 
substances are drugs, and as such cannot fail even in small quantities 
to exercise a toxic effect of some sort on the system; that finally their 
use is objectionable, as allowing the employment in certain foods of 
old materials that have in some cases already undergone incipient 
decomposition before the addition of the antiseptic, and are thus un- 
wholesome. 

Regulation of Antiseptics in Food. — In the absence of legislation 
directly prohibiting the use of any of the above-named antiseptics, and 
in view of the difference of opinion regarding their toxic effects when 
present in small quantities, it is difficult to maintain a complaint under 
the general food laws as they exist in most states, basing the complaint 
solely on their harmfulness. In some localities certain antiseptics are 
specifically allowed and others are prohibited. Some of the states, as, 
for example, Massachusetts, have special laws under which it is required 
that in the case of all foods thus treated, the name and percentage of such 
antiseptics as are used must appear plainly on labels of the packages 
or containers thereof, such a provision being based on the assumption 
that the general public should be informed of what they are buying, where 
any doubt exists as to the wholesomeness of any ingredient present. 
Where such laws as these are in force, the chemist's task is compara- 
tively easy, in that conviction in court is not dependent on his individual 
opinion regarding the toxic effects of the antiseptic employed. 

Before the harmfulness or wholesomeness of these newer preservatives 
can be established beyond a doubt, a large number of physiological 
experiments must be tried on an extensive scale on human beings, using 
the amounts actually present in foods. The large number of tests already 
made on the effects of feeding excessive doses of these substances to dogs 
and other animals, as well as artificial digestion experiments, while no 
doubt useful in a way, can never be universally accepted as conclusive. 
It must not be forgotten, however, that even if any of these substances, 
as used in food, appear to have little or no effect on people in good 
health, they cannot be assumed to be equally harmless to those who are 
inclined to be delicate or sickly, so that by far the fairest restrictive 



FOOD PRESERl^ATll^ES. 663 

measures would seem to be along the line of compelling the honest 
labelling on the package of the preservatives employed. 

Commercial Food Preservatives. — A large number of commercial 
preparations arc sold for purposes of presen'ing specific articles of food 
and are put out under trade names that usually convey no suggestion 
of their true character. Some of these consist of a single antiseptic sub- 
stance, such as salicylic acid, ammonium fluoride, calcium sulphate, 
borax, or benzoic acid, wrhile others are mixtures of several antiseptics, 
of which the following are typical examples, showing their composition 
as found, together with the amount of the mixture to be employed. 

A. Recommended for sausage meat, using 8 ounces per 100 pounds 
of meat: 

Borax 36% 

Salt 46% 

Sahpeter 18% 

(Colored with an anilin dye.) 

B. Recommended for cider and ketchup. 

A 34% solution of beta-naphthol in alcohol, using 2 fluid ounces to 
45 gallons of cider, or ih ounces to 10 gallons of ketchup. 

C. Recommended for beer, using i J ounces per barrel of beer: 

Salt 45% 

Salicylic acid 27% 

Sodium carbonate and salicylate 28% 

D. Recommended for chopped meats, using i ounce to 50 pounds of 
meaf 

Sodium sulphite 65% 

Borax 35% 

E. Recommended for curing beef, hams, tongues, bacon, pig's feet, 
etc.: 

Borax 28% 

Boric acid 1 2% 

Sodium chloride 35% 

Potassium nitrate 25% 

F. Recommended for milk and cream: 

Boric acid 75% 

Borax 25% 



664 FOOD INSPECTION AND ANALYSIS. 

G. Recommended for jellies, jams, preserves, mince-meat, and syrups, 
using from i to 2 ounces of preservative to 100 pounds of product: 

Sodium benzoate 50% 

Boric acid 40% 

Sodium chloride 5% 

Sodium bicarbonate 5% 

H. Recommended for ketchup and tomato pulp, using from 6 to 
8 ounces to 45 gallons of the product : 

Sodium benzoate 50% 

Sodium chloride 40% 

Sodium sulphite 10% 

/. Recommended for keeping butter from becoming tainted or rancid, 
also for salt codfish, using 8 to 12 ounces per 100 pounds butter: 

Boric acid • 25% 

Borax 50% 

Sodium chloride 25% 

J. Recommended for eggs (surface application). A saturated solu- 
tion of salicylic acid in 3 quarts of water, i quart strong alcohol and 7 
ounces of glycerin. 

FORMALDEHYDE. 

Formaldehyde (HCHO) is a gas formed by the action of a red-hot 
spiral of platinum wire on vaporized methyl alcohol. It is also pro- 
duced by the dry distillation of calcium formate. In the market it com- 
monly appears in the form of a 40% solution of the gas in water under 
the name of formalin, and for use as a food preservative dilute solutions 
of from 2 to 5 per cent strength are usually employed. Its use as a food 
preservative is comparatively modem. Formaldehyde, while not con- 
fined exclusively to milk products, is, as a matter of fact, more com- 
monly used in these than in other foods. Its prompt and direct action 
in checking or preventing the growth of lactic acid bacteria renders it 
especially desirable for use as a milk and cream preservative, from the 
standpoint of the dairy man who does not concern himself as to whether 
or not its use is injurious or illegal. 

When present in milk to the extent of i part formaldehyde to 20,000 
parts milk (a proportion quite commonly employed), the sample is kept 



FOOD PRESERyATI^ES 665 

sweet for four days in summer weather, when under ordinary conditions, 
the milk untreated would curdle in less than forty-eight hours. 

Determination of Formaldehyde in the Commercial Preservative. — 
(i) lodomclric Method* — Mix 10 cc. of the aldehyde solution (diluted 
if necessary to a strength not exceeding 3% of formaldehyde) with 25 cc. 
of tenth-normal iodine solution, and add drop by drop a solution of sodium 
hydroxide, till the color of the liquid becomes clear yellow. The solution 
is set aside for at least ten minutes, after which hydrochloric acid is added 
to set free the uncombined iodine, and the latter is titrated back whh 
tenth-normal thiosulphate. Two atoms of iodine are equivalent to 
one molecule of formaldehyde, in accordance with the following reactions : 

6NaOH+6I =NaI03-f 5NaH-3H20. 

3CH,0-FNaI03 =3CHA+NaI. 

SNal + NalOg-f 6HC1 = 6NaCl-f Ie+ 3H,0. 

(2) Method oj Blank and Finkenbeiner.'\— Three grams of the solu- 
tion are weighed into a tall Erlenmeyer flask, to which is then added 
from 25 to 30 cc. of twice-normal sodium hydroxide. 50 cc. of pure 
2.5 to 3 per cent hydrogen peroxide solution are next gradually run in 
during a space of from three to ten minutes, through a funnel placed in 
the neck of the flask to prevent spurting, and the solution is allowed to 
stand for two or three minutes, after which the funnel is washed with 
water. 

Finally the unused sodium hydroxide is titrated with twice-normal 
sulphuric acid, using litmus as an indicator. The less formaldehyde 
in the sample, the longer the mixture should stand after addition of the 
hydrogen peroxide, to complete the reaction. When less than 30% is 
present, it should stand at least ten minutes. 

Ascertain the percentage of formaldehyde, by multiplying by 2 the 
number of cubic centimeters of soda solution used, when 3 grams of the 
sample are taken. 

(3) Ammonia Method. X — Weigh 10 grams of the formaldehyde solu- 
tion into a flask, and treat with an excess of ammonia. Cork the flask 
and shake frequently during several days. The formaldehyde is by this 
process converted into hexamethylamine. 

Transfer the solution to a tared platinum dish, and evaporate nearly 

* Zeits. anal. Chem., 1897, 36, pp. 18-24; abs. Analyst, 22, p. 221. 

t Ber., 31 (17), 2979. 

J Conn. Exp. Sta., Annual Report, 1899, p. 143. 



666 FOOD INSPECTION AND ANALYSIS. 

to dryness on the top of a closed water-bath. Finally the dish is trans- 
ferred to a desiccator, and the drj'ing continued over sulphuric acid to 
constant weight. The per cent of formaldehyde is calculated from the 
weight of the hexamethylamine, making a correction for the residue left 
by the formaldehyde itself by direct evaporation: 

6CH,0 + 4NH,OH = (CH,)eN,+ loH^O. 

Or an excess of a standardized ammonia solution may be added in 
the first place, the excess of ammonia being distilled off and titrated with 
standard acid, calculating the per cent of formaldehyde by the amount 
of ammonia absorbed. 

Detection of Formaldehyde. — Methods have previously been given 
for the detection of formaldehyde in milk. Pure milk furnishes a con- 
venient reagent for the detection of formaldehyde in various preparations. 
A solution of the sample to be tested is acidified with phosphoric acid, 
subjected to distillation, and the first few cubic centimeters of the dis- 
tillate are tested for formaldehyde as follows: 

(i) Hydrochloric Acid and Ferric Chloride Test. — -Add a few drops 
of the suspected distillate to about lo cc. of pure milk (previously proved 
free from formaldehyde) in a porcelain casserole, and carry out the test 
as described on page 140. 

(2) Hehnefs Sulphuric Acid Test. — Apply the test as described on 
page 140 to 10 cc. of pure milk to which a few drops of the suspected 
distillate have been added. 

(3) Resorcin or Carbolic Acid Test. — To about 10 cc. of the distillate 
to be tested, add a few drops of a 1% solution of carbolic acid or resorcin, 
mix thorbughly, and carefully pour the liquid down the side of a test-tube 
containing concentrated sulphuric acid. In the presence of formaldehyde, 
a rose-red zone is formed at the junction of the two liquids, sensitive to 
I part in 200,000. If formaldehyde be present to an extent exceeding 
I part in 100,000, a white turbidity or precipitate is formed above the 
colored zone. 

(4) Phenylhydrazine Hydrochloride Test.* — One gram of phenyl- 
hydrazine hydrochloride and li grams sodium acetate are dissolved in 
10 cc. of water. Add 2 to 4 drops of this reagent, and an equal amount 
of sulphuric acid, to i or 2 cc. of the distillate to be tested in a test-tube. 
A green coloration is produced in the presence of formaldehyde. 

* Jour. Am. Chem. Soc, 22, p. 135. * 



FOOD PRESERl^ATli/ES. 667 

If present in a very small amount (say i part formaldehyde in 200,000), 
heat is necessary to bring out the color. 

Determination of Formaldehyde. — The exact quantitative determina- 
tion of formaldehyde in food products is difhcult, owing to its extreme 
volatility as well as the uncertainty of the compounds which it forms with 
proteids. A rough idea of the amount present may often be gained by 
the intensity of the colorations produced in carrying out the various 
qualitative tests. 

Formaldehyde in the small amount present in food products may be 
roughly determined by the potassium cyanide method (p. 141), on 
separate portions of the distillate of about 20 cc. each, collecting the 
distillate as long as an appreciable amount of formaldehyde is shown 
therein. 

BORIC ACID. 

Boric or boracic acid is commonly obtained in impure form from 
lagoons or fumaroles of volcanic origin in Tuscany. It is afterwards 
purified by recrystallization. It is weakly acid, and readily soluble in 
water and in alcohol. Its alcoholic solution, even when the acid is present 
in small quantity, burns with a characteristic green flame. The acid 
is quite volatile with steam. 

Borax, the most commonly known salt of boric acid, is found native 
in Italy, California, and elsewhere, and is also made from boric acid. 
It is mildly alkaline, and readily soluble in water. 

Boric acid and borax, either used separately or mixed, have long been 
used as preservatives, especially in animal foods. A mixture of 3 parts 
boric acid and i part borax has been found ven,- effective as a milk and 
butter preservative, as well as for meat products. 

Determination of Boric Anhydride in Commercial Preservatives. — 
Gladding Method.* — A 150-cc. flask, Fig. 117, is arranged with a doubly 
perforated stopper having two tubes, one of which, the inlet-tube reach- 
ing nearly to the bottom, connects it with a larger flask, while the other 
or outlet-tube communicates with a Liebig condenser, which in turn 
delivers into a receiving- flask. In the 150-cc. flask, i gram of the 
powdered sample is placed, with about 20 cc. of 95% methyl alcohol and 
5 cc. of 85% phosphoric acid. The larger flask is then filled two-thirds 
full of methyl alcohol, and heated on the water-bath after the apparatus 
has been connected up. Heat is also applied to the 150-cc. flask, the 

* Jour. Am. Chem. Soc, 20, i8g8, p. 288. 



668 



FOOD INSPECTION AND ANALYSIS. 



whole arrangement being such that a continuous current of methyl alcohol 
vapor bubbles through the liquid in the smaller flask, the heat being so 
regulated that from 15 to 25 cc. of methyl alcohol remains in the 150- 
cc. flask, while about 100 cc. of distillate passes into the receiving-flask 
in half an hour. Continue the distillation till all the acid has passed 
over, which is usually accomplished by distilling 100 cc. By a gentle 
aspiration upon the receiving- flask, loss by leaking may be avoided. 




Fig. 117. — ^Apparatus for Determining Boric Acid According to Gladding. 

Prepare a mixture of 40 cc. of glycerin and 100 cc. of water, and care- 
fully neutralize, using phenolphthalein as an indicator. Add this mi.xture 
to the distillate, and titrate the whole with tenth-normal sodium hydroxide. 
Run a blank with the reagents alone, deducting any acidity. For the fac- 
tors for calculation see page 670. 

Detection of Boric Acid and Borates. — These are best tested for in 
most cases in a solution of the ash of the sample, the quantity to be used 
for the test depending largely on the case in hand. With meat products 
and canned goods, about 25 grams are taken for the test, being lirst made 
distinctly alkaline with lime water, dried over the water-bath, and burned. 
The ash is boiled vnth from 10 to 15 cc. of water, and tests made on the 
solution. With such products as salt codfish, which is preserved by 
brushing or coating with boric mixture, portions of the coating may be 
scraped off and boiled in water, the tests being made on the aqueous 
solutions. 



FOOD PRESERyATiyES. 66 g 

(i) The Turmeric-paper Test. — The most delicate test for boric acid, 
free or combined, is made by the aid of turmeric-paper, prepared by soak- 
ing a smooth, thin grade of tilter-paper in an alcoholic tincture of pow- 
dered turmeric. The paper is afterwards dried and cut into strips, which 
are kept for convenience in a wide-mouthed bottle in a dark place. 

Slightly acidulate the ash of the sample to be tested with a few drops 
of dilute hydrochloric acid, avoiding an excess of acid. Then dissolve the 
ash in a few drops of water and thoroughly saturate a strip of the tur- 
meric-paper in the solution. On drj'ing the paper, if boric acid cither free 
or combined be present, a cherr\'-red coloration will be imparted to the 
paper, the depth of color depending on the amount present. As a con- 
firmator)' test, apply a drop of dilute alkali to the reddened paper, and 
a dark-olive color will be due to boric acid, sharply to be distinguished 
from the deep-red color produced when an alkaline solution is applied 
to ordinar}' turmeric-paper. The turmeric-paper reaction is delicate to 
I part in 8,000. 

(2) Tincture of Turmeric Test. — To the solution to be tested, slightly 
acidified with hydrochloric acid, add an equal volume of saturated tinc- 
ture of turmeric in an evaporating-dish, and heat for a minute or two. A 
red color, light or dark, depending on the amount of the preservative, 
is produced if boric acid be present, changed to an olive color by the 
addition of dilute alkali, after cooling. 

(3) The Flame Test. — A few cubic centimeters of alcohol are added to 
the dish containing the slightly acidulated ash of the sample to be tested, or 
to the acidulated dried residue from the evaporation of the aqueous solution 
of the suspected preservative, and after mixing by the aid of a stirring- 
rod, the alcohol is ignited. In the presence of any considerable portion 
of free or combined boric acid, a greenish tinge will be observed in the 
flame of the burning alcohol, especially at the first flash, due to the boric 
ether formed. This test is by no means as delicate at the paper test. 

Determination of Boric Acid in Foods. — (i) Thompson's Method.* — 
Add I or 2 grams of sodium hydroxide to 100 grams of the sample, and 
evaporate to dryness in a platinum dish. Char the residue thoroughly, and 
boil with 20 cc. of water, adding hydrochloric acid dro]) by drop till all but 
the carbon is dissolved. In burning, avoid too high a heat, simply charring 
sufficiently to insure a clear solution with water. Transfer by washing 
to a loo-cc. graduated flask, taking care that the volume does not exceed 
50 or 60 cc. Add half a gram of dry calcium chloride, then a few drops 

* Analyst, 18, p. 184. 



670 FOOD INSPECTION AND ANALYSIS. 

of phenolphthalein solution, and next a 10% solution of sodium hydroxide, 
till a permanent pink color persists. Finally add 25 cc. of lime-water. 
By this means all phosphoric acid is precipitated in the form of calcium 
phosphate. Make up to the loo-cc. mark with water, shake, and pour 
upon a dry filter. To 50 cc. of the filtrate add sufficient normal sulphuric 
acid to remove the pink color. Then add a few drops of methyl orange, 
and continue the addition of sulphuric acid till the yellow is just turned 
to pink. Tenth-normal sodium hydroxide is then added * till the liquid 
takes on a faint yellow, excess of alkali being avoided. The salts of the 
acids present at this time are all neutral to phenolphthalein except boric 
acid and carbon dioxide. Boil the solution to e.xpel the carbon dioxide, 
cool, add a little more phenolphthalein, and a quantity of glycerin equal 
in volume to the solution. Finally titrate with tenth-normal sodium 
hydroxide to a permanent pink color. Each cubic centimeter of tenth- 
normal sodium hydroxide equals 0.0062 gram crystallized boric acid, 
H3BO3, or 0.0035 gram boric anhydride, B2O3, or 0.00955 gram crystal- 
lized borax, NajB^O^ioHoO. 

(2) Gooch's Method. — Mix 400 to 500 grams of the substance with 
10 grams of calcium hydrate, evaporate to dryness over a water-bath in 
a platinum dish, and burn cautiously to an ash. Dissolve the residue in 
cold nitric acid, and add an excess of silver nitrate to precipitate the chlo- 
rine. Filter, make up to 500 cc. with water, shake, and measure out 25 cc. 
vnto a 200-CC. flask fitted with a stopper provided with an outlet-tube, 
and with a separatory funnel forming virtually a thistle-tube, capable of 
being closed with a glass stop-cock. Through the outlet-tube connect 
the flask with a Liebig condenser provided with an adapter which can 
dip below the liquid in the receiver. As a receiver, use a 150-cc. tared 
platinum dish, which contains a weighed quantity of ignited lime in water. 

Add through the thistle-ti.be 10 cc. of methyl alcohol to the contents 
of the flask, close the stop-cock therein, and distill the contents in a paraf- 
fin-bath at a temperature of 140° C, constantly stirring the liquid in the 
receiver to keep it alkaline during the distillation. Add five successive 
portions of methyl alcohol of 12 cc. each to the distilling-flask, and con- 
tinue the distfllation till all the alcohol has passed over. Finally evaporate 
to drj'ness the contents of the platinum dish, and ignite over a blast-lamp 
to constant weight. Multiply the increased weight due to boric oxide by 
2.728 to give the equivalent in borax. 

* If the value of the standard alkali solution is not absolutely certain, it had best be 
restandardized against pure crj-stallized boric acid, 0.31 gram of which should neutralize 
50 cc. of tenth-normal alkali. 



FOOD PRESERl^ATiyES. 671 



SALICYLIC ACID. 



Salicylic acid (HC7H5O3) is a white, crj'stalline, strongly acid powder, 
made synthetically by treatment of carbolic acid with sodium hydroxide 
and carbon dioxide, or naturally from methyl salicylate (which occurs in 
oil of wintergreen to the extent of about 90%), by treatment of the winter- 
green oil with strong potash lye. Most of the commercial salicylic acid is 
of the synthetic variety. Pure salicylic acid crystallizes from alcoholic 
solutions in 4-sided prisms, and from aqueous solution in long, slender 
needles. It melts at 155° to 156° C. It is slightly soluble in cold water 
(i part in 450), and much more so in hot water. It is readily soluble in 
ether, alcohol, and chloroform. 

It is frequently found on the market as a food preservative in the form 
of the much more soluble sodium salt, sodium salicylate, (NaCyHjOa), 
which is, however, converted into salicylic acid when added to acid- 
frait preparations, condiments, and liquors. 

Sodium salicylate is a white, amorphous powder, soluble in 0.9 parts 
water and in 6 parts alcohol. It is prepared by treating salicylic acid 
with a strong, aqueous solution of sodium carbonate, and afterwards 
purifying. If a known weight of the powdered preservative be ignited, 
and a solution of the ash titrated with tenth-normal sulphuric acid, v.sing 
cochineal as an indicator, eacli cubic centimeter of the acid is equivalent 
to 0.0160 gram of sodium salicylate. 

Salicylic acid is largely used as a preservative of jellies, jams, and 
frait preparations, canned vegetables, ketchups, table sauces, wines, 
beer, and cider. It is rarely used in milk and milk products, or in meats. 
Bucholz has shown that 0.15% of salicylic acid is suiScient to prevent 
bacteria from developing in ordinary organic substances, while as small 
a quantity as 0.04% produces a marked restraining influence. 

Detection of Salicylic Acid. — If the sample to be tested is of a similar 
nature to jelly, jam, ketchup, cider, etc., or capable of getting into aque- 
ous solution, slightly acidify the liquid or pasty material, diluted, if neces- 
sary, with weak sulphuric (if not already acid), and shake directly with 
an equal bulk of ether, petroleum ether, or chloroform, in a corked flask, 
or in a separatory funnel. If the sample be too thick in consistency to 
shake directly, macerate in a mortar with alkaline water, and strain through 
cloth. Acidify the filtrate with dilute sulphuric acid, and then proceed 
to shake with the immiscible solvent as above. Separate by decantation or 
otherwise the immiscible solvent containing the preservative, if present, and 



672 FOOD INSPECTION AND ANALYSIS. 

allow it to evaporate in an open sliallow dish, either at room temperature 
or at a low heat. In case an emulsion forms on shaking, which is quite 
apt to happen, especially with ether for a solvent, divide the whole mixture 
between two tubes of a centrifuge of the form shown in Fig. ii, and 
whirl for three minutes at a high rate of speed. This usually ser\'es to 
break up the most obstinate emulsion, so that it is easy to separate by 
decantation. If a considerable amount of salicylic acid be present, it 
will sometimes appear in the residue in the form of fibrous cn.-stals.* 

(i) To a portion of the dry residue add a drop of ferric chloride solu- 
tion. A deep purple or violet color indicates salicylic acid.f If dov.bt 
exists as to the color, dilute with water, which often serves to bring out 
a distinctive purple coloration otherwise unobservable. 

(2) Another portion of the residue may be heated with methyl alcohol 
and sulphuric acid. If salicylic acid be present, the well-known odor of 
methyl salicylate will be produced. 

(3) A portion of the dr)- ether extract is warmed gently with a drop 
of concentrated nitric acid, and two or three drops of ammonia are added. 
Yellow ammonium picrate will be formed if a considerable quantity of 
salicylic acid be present, and a thread of wool free from fat may be dyed 
by soaking therein. This test is by no means as delicate as the ferric 
chloride color test. 

Determination of Salicylic Acid. — A rough quantitative estimation 
of salicylic acid may be made colorimetrically, by carrying out more 
carefully the method already given for its detection with ferric chloride. 
Make several extractions of a weighed or measured portion of the sample 
to be tested with ether or chloroform. Evaporate the combined extracts to 
dryness, and take up this residue with several washings of strong alcohol, 
which are filtered into a narrow, graduated cylinder or tube. Treat with 
sufficient ferric chloride solution to develop the maximum color, make up 
to a given volume with water, and match the color against varying portions 
of a standard dilute alcoholic solution of known strength of pure salicylic 
acid, measured into similar graduated tubes, treated with ferric chloride, 
and made up to the same volume as the sample to be tested. 

* Instead of evaporating the separated ether to dryness, the method of extraction of the 
salicylic acid by treatment of the ether with dilute ammonia may be used (p. 143). In this 
case the ether may be recovered. 

t Peters (U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 160) advises the use of chloro- 
form as more convenient for extraction when testing for salicylic acid, and recommends that 
the chloroform extract without evaporation be shaken in a test-tube with a drop of ferric 
chloride reagent and a little water. In the presence of salic\-lic acid, the violet color will 
be apparent in the supernatant aqueous layer. 



FOOD PRESERy/ITiyES. 673 



BENZOIC ACID. 

Benzoic Acid (HCjHsOj) is produced by the oxidation of a large 
number of organic substances, particularly toluene. It is also extracted 
by sublimation from gum benzoin, which exudes from the bark of the 
Styrax benzoin, a tree growing in Java, Sumatra, Borneo, and Siam. 
Most of the commercial benzoic acid is made from toluene by treatment 
with chlorine and subsequent oxidation. 

Benzoic acid crystallizes in leaflets, having a silky luster. It is odor- 
less when cold, is soluble in 200 parts of cold, and 25 parts of boiling 
water, and readily dissolves in alcohol, ether, and chloroform. Its melt- 
ing-point is 120°, and it sublimes at a slightly higher temperature . 

Sodium Benzoale (NaCjHjOo) is the salt most largely used in commer- 
cial preservatives, being much more soluble than the acid itself, into 
which, however, it is converted when put into acid fruit preparations. 
Sodium benzoate is prepared by adding benzoic acid to a concen- 
trated hot solution of sodium carbonate till there is no longer efferves- 
cence, and then cooling, and allowing the sodium benzoate to crystallize 
out. 

In titrating solutions of ignited sodium benzoate with tenth-normal 
sulphuric acid, each cubic centimeter of the standard acid is equivalent 
to 0.0144 gram of the benzoate. 

Sodium benzoate is a white, amorphous powder, having a sweetish, 
astringent taste. It is soluble in 1.8 parts of cold water, and in 45 parts 
of alcohol. Benzoic acid is commonly found as a preservative of ketchups, 
jellies, jams, and canned goods, and less often in wines and liquors. 

Detection of Benzoic Acid. — The sample is extracted with ether or 
chloroform in precisely the same manner as directed for salicylic acid. 
In fact, it is nearly always desirable to test the same sample for both 
these preservatives, since either and sometimes both are apt to be found 
in the same class of food products. For this purpose, the ether or chloro- 
form extract is conveniently divided and evaporated to drj'ness in separate 
dishes, one of the residues to be tested for salicylic, and the other for 
benzoic acid.* A considerable amount of benzoic acid is apparent in the 
residue as shining crystalline scales or needles. 

(i) Ferric Chloride Test. — A portion of the residue from the ether 
extract is dissolved in ammonia, and evaporated to dryness over the water- 
bath. The residue is stirred in a few drops of warm water, and the latter 

* See also method on p. 142. 



674 FOOD INSPECTION AND AN/fLYSlS. 

solution is poured through a filter, and collected in a narrow test-tube. 
A drop of ferric chloride is added, and in the presence of benzoic acid 
a flesh-colored precipitate of ferric benzoate is produced, ver\' character- 
istic and unmistakable, because of its peculiar color, when the solution 
in which the test is made is colorless. It occasionally happens, however, in 
the case of jellies, jams, and ketchups, that these preparations are arti- 
ficially colored with a dyestuff that persists by its depth of color in obscur- 
ing that of the ferric benzoate, especially when only a small amount of 
benzoic acid is present. Again, in such products as sweet pickles, a 
precipitate of basic ferric acetate might also come down with the ferric 
benzoate, and thus confuse. In such cases one of the following methods 
should be carried out. 

(2) Sublimation Method* — Evaporate an ammoniacal solution of the 
ether extract to dryness in a large watch-glass, by the aid of a gentle heat. 
Fasten with clips or otherwise a second watch-glass, to the first, edge to edge, 
so as to form a double convex chamber, with a cut filter-paper between. 
Place upon a small sand-bath and heat. Benzoic acid, if present, will 
sublime upon the surface of the upper glass in minute needles, recogni- 
zable under the microscope. It may further be tested by determining 
the melting-point of the cr)'stals, or by treating the residue with ammonia, 
and after evaporation and solution of the residue, applying the ferric 
chloride test as above. 

(3) Peter's Oxidation Melhod.-\ — This method depends on the oxida- 
tion of benzoic to salicylic acid by the action of sulphuric acid and barium 
peroxide, and should, of course, be applied only when salicylic acid has 
been first proved absent. 

A portion of the residue, say o.i gram, from the ether or chloroform 
extraction of the suspected sample, is transferred to a large test-tube, and 
dissolved in from 5 to 8 cc. of concentrated sulphuric acid. Small por- 
tions of barium peroxide are then successively added, and the tube shaken 
in cold water to keep the temperature down, using from 0.5 to 0.8 gram 
of the peroxide in all. This should produce a permanent froth on the 
sulphuric acid solution. After standing for half an hour, the test-tube 
is filled three-quarters full of water, and the mixture shaken, quickly 

* Annual Report, Mass. State Board of Health, 1902, p. 486. Food and Drug Reprint, 

P- 34- 

t U.S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 160. 

% In view of the fact that saccharin acts in a similar manner to benzoic acid, the absence 
of saccharin must also first be established. 



FOOD PRESERVATiyES. 675 

cooled, and filtered. The filtrate is then extracted with ether or chloro- 
form, and the extract tested in the regular manner for salicylic acid. 

Mohler's Test for Benzoic Acid.* — The ether extract or the distillate 
from the suspected sample is evaporated to dryness, and the residue treated 
with 2 or 3 cc. of strong sulphuric acid. Heat till white fumes appear; 
organic matter is charred and benzoic acid is converted into sulpho-benzoic 
acid. A few crystals of potassium nitrate are then added. This causes 
the formation of metadinitrobenzoic acid. When cool, the acid is diluted 
with water, and ammonia added in excess, followed by a drop or two of 
ammonium sulphide. The nitrocompound becomes converted into am- 
monium metadiamidobenzoic acid, which possesses a red color. This 
reaction takes place immediately, and is seen at the surface of the liquid 
without stirring. 

SULPHUROUS ACID AND THE SULPHITES. 

Free sulphurous acid is not often, if ever, applied as such to foods, 
but from the "sulphuring" process, to which wine casks are often sub- 
jected, the free acid is sometimes found in the wine. The sulphurous 
acid salts most commonly employed as food preservatives are the bisul- 
phites of sodium and calcium, NaHS03 and Ca(HS03)3. Others used 
to some extent are the normal sodium sulphite, and also potassium and 
ammonium sulphite. The sulphites are usually commercially prepared 
by passing sulphurous acid gas through strong solutions of the carbon- 
ates. Acid sulphites are formed by an excess of the sulphurous acid 
in the solution of the sulphite. The acid sulphites are distinguishable 
from the sulphites by their reactiori with litmus paper, the former being 
acid, while the latter are neutral or feebly alkaline. All of these salts 
have a bitter, salty, and highly sulphurous taste, and possess a very pun- 
gent, irritating odor. With the exception of normal calcium sulphite, 
all of the above are readily soluble in water. 

The sulphites are most commonly used as preservatives of fruit juices, 
ketchups, fruit and vegetable pulps, and meat products. They are fre- 
quently mixed whh other antiseptics, as with the salts of salicylic and 
benzoic acids. 

Detection of Sulphurous Acid. — Mix 100 or 200 grams of the sample 
(finely macerated in a mortar if necessary) with enough water to form a 
thin solution or paste. Acidify with phosphoric acid, transfer to a flask, 
and subject to distillation. The delivery-tube from the condenser should 

* Bui. Soc. Chim., 1890, 3, 414; U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. lop. 



676 FOOD INSPECTION AND yINA LYSIS. 

preferably dip below the surface of a few cubic centimeters of water in 
the receiver. Distill off 20 or 30 cc, treat the distillate with a few drops 
of bromine water, and boil. Then add a little barium chloride reagent. 
A precipitate indicates sulphurous acid. 

Determination of Sulphurous Acid.* — To 25 grams of the sample, 
finely divided in water, if solid or semi-solid, add 25 cc. of a normal 
solution of potassium hydroxide in a 200-cc. flask. Shake thoroughly, 
and set aside for at least fifteen minutes with occasional shaking. 10 cc. 
of sulphuric acid (1:3) are then added with a little starch solution, and 
the mixture is titrated with N/50 iodine solution, introducing the iodine 
solution quite rapidly, and adding it till a distinct fixed blue color is 
produced, i cc. of the iodine solution is the equivalent of 0.00064 
gram SOj. 

FLUORIDES, FLUOSILICATES, AND FLUOBORATES. 

These substances all possess strong antiseptic qualities, and while no 
instances are recorded of the use of the last two classes of compounds in 
this countr}', the use of fluorides as a preservative of beer is practiced 
to some extent. The salt most commonly used is ammonium fluoride 
(NH4F), preparations of this salt being sold commercially under various 
trade names as beer preservatives. Ammonium fluoride exists as small, 
deliquescent, hexagonal, flat cr)'stals. Its taste is strongly saline. It 
is soluble in water, and slightly soluble in alcohol. Sodium fluoride 
(NaF) occurs as clear, lustrous crystals, soluble in water. 

Detection of Fluorides.f — One hundred grams or so of the beer or 
other solution to be tested are made alkaline with ammonium carbonate 
and heated to boiling. The fluorine is then precipitated by the addi- 
tion of a few cubic centimeters of 10% calcium chloride solution, and 
the boiling continued for a few minutes. Filter, wash with water, dry 
the precipitate upon the filter, and ignite in a platinum crucible. Coat 
a small watch-glass with wax or paraffin, through which by a pointed 
instrument marks are made, laying bare the glass. Add i cc. of strong 
sulphuric acid to the ash in the crucible, cover with the glass, and heat 
on the top of a water-bath at a temperature not exceeding 80° C. for an 
hour. At the end of this time remove the paraffin coating from the glass, 
and in the presence of one milligram or more of fluoride, the marks will 

* U. S. Dept. of .\gric., Bur. of Chem., Bui. 65, p. go. 

\ Ibid., p. 91; Neviere and Hubert, Mon. Sci., 1895, (4) 9, p. 324. 



FOOD PRESERy/tTiyES. 677 

be found etched upon the glass. Small amounts of silica impair the 
delicacy of the test. 

Detection of Fluoborates and Fluosilicates.* — Two hundred cc. of 
the wine or other sample are made alkaline with lime water, evaporated 
to dryness, and ignited. The crude ash is first extracted with water 
acidified with acetic acid, and the solution fihered. The insoluble residue 
is again ignited and extracted with dilute acetic acid, which is filtered off 
and added to the first extract. The filtrate contains the boric acid, if 
present, and this is tested for as directed on page 669. Calcium silicate 
or fluoride, if present, is in the insoluble portion. 

Incinerate the filter with the insoluble portion, transfer the ash to a 
test-tube, mix with some silica, and add a little concentrated sulphuric 
acid. A small U-tube should be attached to the test-tube, containing 
a very little water. The test-tube is immersed for half an hour in a 
beaker of water kept hot on a steam-bath. In the presence of fluoride, 
silicon fluoride will be generated, and will be decomposed by the water, 
forming a gelatinous deposit on the walls of the tube. 

If both boric and hydrofluoric acids are found, the compound present 
is undoubtedly a borofluoride. If no boric acid is found, but silicon 
fluoride is detected, repeat the operation, but without the added silica. 
If the silicon skeleton is then formed, fluosilicate is probably present. 

BETA-NAPHTHOL. 

Beta-naphthol (C10H7OH) is a phenol, occurring naturally in coal- 
tar, but the commercial product is more commonly prepared artificially 
from naphthalene by digesting the latter with sulphuric acid, and fusing 
the product with alkali. It is a colorless, or pale buff-colored powder, 
with a faint phenolic odor and a sharp taste. It is slightly soluble in water, 
and readily soluble in alcohol, ether, and chloroform. Its melting-point 
is 122° C. In alcoholic solution it is neutral to litmus. 

It is used to some extent in alcoholic solution as a preservative of 
cider. 

Detection of Beta-Naphthol. — Buhe f states that if an ethereal extract 
of beta-naphthol is evaporated to dryness, and the residue dissolved in 
hot water made first faintly alkaline with ammonia, and then faintly acid 
with very dilute nitric acid, a beautiful rose color will be developed on 
the addition of a drop of fuming nitric acid or of a nitrite. He declares 

* U. S. Dept. of Agric, Bur. of Chem., Bui. 59, p. 63. 
t Analyst, 13 (1888), p. 52. 



678 FOOD INSPECTION AND ANALYSIS. 

the test to be a delicate one, but it is apparently sometimes obscured by 
interfering substances, which the ether may dissolve. It should also be 
carried out in a faint light, as strong sunlight affects the color. 

Ferric chloride, when applied to an aqueous solution of beta-naph- 
thol, produces a greenish coloration. 

Shake about 50 grams of the sample to be tested with chloroform in 
a separatory funnel, evaporate the chloroform extract to a small volume 
(say I or 2 cc), transfer to a test-tube, add 5 cc. of an aqueous solution 
of potassium hydroxide (1:4), and warm gently. If beta-naphthol is 
present, a deep-blue color will appear in the aqueous layer, turning through 
green to light brown. 

ASAPROL, OR ABRASTOL. 

These are trade names for calcium a-mono-sulphonate of beta- 
naphthol, Ca(C,t,H6S030H)2, a white, odorless, scaly powder, sometimes 
slightly reddish, obtained by the action of heated sulphuric acid on beta- 
naphthol, the resuhing compound being afterwards treated with a calcium 
salt. It is readily soluble in water and alcohol, and is neutral in reaction. 
Its taste is at first slightly bitter, but rapidly changes to sweet. It decom- 
poses at about 50° C. 

The writer is unaware of any instance of the presence of this substance 
in foods, but its character is such as to adapt it for use as a preservative 
of wines and possibly other food products. It has long been regarded 
as a possible preservative, and the analyst should be prepared to 
encounter it at any time. 

Detection of Asaprol. — Sinabaldi's Method* — The portion of the 
solution to be tested (say 50 cc.) is made slightly alkaline with ammonia, 
and shaken with 10 cc. of amyl alcohol in a separatory funnel. Alcohol 
is often useful in breaking up an emulsion if there is one. Separate the 
amyl alcohol extract, which if turbid is filtered, and evaporate to dry- 
ness. Wet the residue with about 2 cc. of nitric acid (i: i), heat on the 
water-bath till the volume is about i cc, and wash with a few drops of 
water into a narrow test-tube. Next add about 0.2 gram of ferrous sul- 
phate and ammonia in excess, a drop at a time, constantly shaking the 
solution. If a reddish-colored precipitate is formed, it is dissolved by 
the addition of a little sulphuric acid, and further additions of ferrous 
sulphate and ammonia are made as before. When a dark-colored or 

* Mon. Sci., 1893, (4) 7, p. 842; U. S. Dept. of Agric, Bur. of Chem., Bui. $9. P- pi- 



FOOD PRESERyATIl/ES. 679 

green precipitate appears, add 5 cc. of alcohol, dissolve in sulphuric 
acid, shake, and filter. If abrastrol be present to the extent of o.oi gram 
or more, a red coloration is observed, while in its absence, the filtrate 
is colorless or faintly yellow. 

If the solution to be tested is a fat, it should be melted and extracted 
with hot 20% alcohol, which is evaporated to dryness, and the above test 
carried out on the dry residue. 

REFERENCES ON PRESERVATIVES AND THEIR USE IN FOOD. 

Abel, R. Zum Kampfe gegen die Konservierung von Nahrungsmitteln durch Anti- 

septica. Hyg. Runds., 1901, 265-281. 
Annett, H. E. Boric Acid and Formaline as Milk Preservatives. Thompson Yates 

Lab. Reports, Liverpool, Vol. II, 1900, pp. 57-67. 
Baldwin, H. B. Toxic Action of Sodium Fluoride. Jour. .\m. Chem. Soc, 21, 

1899, p. 517. 
Benedicentti. .\ction of Formaldehyde on Various Proteid Substances. Archw. f. 

Anat. u. Physiolog., 1897, p. 219. 
BiscHOFF, H., and Wintgen, U. Beitrage zur Konservenfabrikation. Ztsch. fur 

Hyg., Bd. 34, 1900, Heft 3, 496-513- 
Bliss and Novy. Action of Formaldehyde on Enzymes. Jour. Exp. Med., 4, 47. 
CmxTEXDEN, R. H. Influence of Borax and Boracic Acid on Digestion. Diet, and 

Hyg. Gazette, 9, 1893, 25. 
Chittenden and Gies. Effects of Borax and Boric Acid on Nutrition. New York 

Med. Jour., Feb., 1898. 

Experiments with Borax and Boric .^cid on the Lower Animals. Am. Jour, of 

Phys., Vol. I, No. I, 1898. 
DiOHT, C. F. Effect of Boric Acid and Borax on the Human Body, and with Particular 

Reference to their Use as Food Preservatives. Minneapolis, 1902. 
GouiN, R. Le Beurre et r.\cide Borique. Jour. d'Agricult prat., 1900, p. 14-16. 
Gruber. Ueber die Zuliissigkeit der Verwendung der Fluoride zur Konservierung 

von Lebensmittel. Das Oesterr. Sanitatsw., 1900, 4. 

Ueber die Zulassigkeit der Verwendung von Chemikalien zur Konservierung von 

Lebensmittel. Das Oesterr. Sanitatsw., 1900. 

Grunbaum, a. S. Note on the Value of Experiments in the Question of Food Pre- 
servatives. Brit. Med. Jour., 1901, p. 1337. 

Halliburton, W. D. Remarks on the Use of Borax and Formaldehyde as Preserva 
lives of Food. Brit. Med. Jour., 1900, pp. 1-2. 

Heffter, a. Ueber den Einfluss der Borsaure auf die .\usnutzung der Nahrung. 
Arbeiten aus dem kaiserUchen Gesundheitsamte, Bd. 90, Part i, 1902, p. 97. 

Hill, A. Antiseptics in Food. Pub. Health Jour., London, 11 (1901), 527. 

Hope, E. W. Preservatives and Coloring Matters in Foods. Thompson Yates Lab. 
Reports, Vol. Ill (1900), pp. 75-78. 

KiSTER, J. Ueber Gesundheitschadlichkeit der Borsauer als Konservierungsmittel fiir 
Nahrungsmittel. Zeit. f. Hygiene, Bd. 37, 1901, Heft 2, p. 225. 



68o FOOD INSPECTION AND ANALYSIS. 

Lauge, L. Beitrage zur Frage der Fleischkonservierungmittel. Borsaure, Borax und 

Schwefeligsauren Natronzusatzen. Mit einem Anhang. Milchkonservierung 

betr. Arch. f. Hygiene, Bd. 40, igoi, 2, pp. 143-186. 
Lebbin, G. Die Konservierung und Farbung von Fleischwaaren. Hyg. Rund., 11, 

No. 23. 
Lebbin u. Kallmann. Ueber die Zuliissigkeit Schwefeligsauer Salze in Nahrungsmit- 

teln. Zeits. fiir offentl. Chem., 7, 17, 324-334. 
Lebbin, G. Preservation and Coloring of Meat Produce. Translated from the 

German. 

Should the Use of Boric Acid as a Food Preservative be Permitted? Translated 

from the German of Die medicinische Woche, Sept., igoi. 
Leffmann, H. Food Preservatives. Penn. Board of Agric, An. Rep., 1897, 535. 

Influence of Preservatives on Digestive Enzymes. Diet, and Hyg. Gazette, 14, 718. 

Hygienic Relations of Boric Acid and Borax. Diet, and Hyg. Gazette, 14, 171. 

Digestive Ferments and Preservatives. Jour. Frankl. Inst., 147 (1899), 97. 

Lepiere. Action of Formaldehyde on Proteids. Bui. Soc. Chem., 21 (1899), p. 729. 
Liebreich, O. Effects of Borax and Boric Acid on the Human System. London, 1902. 

The So-called Danger from the Use of Boric Acid in Preserved Foods. Lancet, 

igoo, p 13-15. 
LoEW. Action of Formaldehyde on Pepsin and Diastase. Jour. f. prakt. Chem., 1888, 

37- P' loi- 
Neumann, R. O. Ueber den Einfluss des Borax auf dem Stoffwechsel des Menschen. 

Arbeiten aus dem kaiserlichen Gesundheitsamte, Bd. 90, Pt. i, 1902, p. 8g. 
Polenske. Ueber den Borsauregehalt von frischen und geraucherten Schweineschin- 

ken. Loc. cit., 167. 
Rideal, S. Formalin as a Milk Preservative. Analyst, 20, 157. 

Disinfection and the Preservation of Food. London and New York, 1903. 

On the Use of Boric Acid and Formic Aldehyde as Milk Preservatives. Public 

Health Jour., London, 11, igoi, 554. 
Rohardt, W. Ueber Konservierung von frischem Fleisch und ueber Fleischkonserven 

von Hygienischen- und Sanitiits-polizeilichem Standpunkt aus. Vierteljahres- 

schrift f. gerichtl. Med., 1901, Heft 2, p. 321. 
Rost, E. Ueber die Wirkungen der Borsaure und des Borax auf den thierischen und 

menschUchen Korper, mit besonderer Beriicksichtigung ihrer Verwendung zum 

Konservieren von Nahrungsmitteln. Arbeiten aus dem kaiserlichen Gesund- 
heitsamte, Bd. go, Part i, 1902, p. i. 
RObner. Ueber die Wirkung der Borsaure auf den Stoffwechsel des Menschen. 

Loc. cit., 70. 
Sonntag, G. Ueber die Quantitative Untersuchung des Ablaufs der Borsaureaus- 

scheidung aus dem menschlichen Korper. Loc cit., no. 
Stroscher, a. Konservierung u. Keimzahlen des Hackfleishes. Arch. f. Hyg., 40, 

1901, p. 291-319. 
TuNiNCLiFFE, F. W., and Rosenheim, O. On the Influence of Formaldehyde upon 

the Metabolism of Children. Jour, of Hygiene (London), Vol. I, 3, 1901. 

On the Influence of Boric Acid and Borax upon the General Metabolism of 

Children. Loc. cit., supra, igoi. Vol. I, No. 2, pp. 168-202. 



FOOD PRESERWATiyES. 68 1 

Vaughan, V. C, and Veenboer, W. H. The Use of Boric Acid and Borax as Food Pre- 
servatives. Am. Medicine, March, 1902. 

Vaillard, L. Les Conserves alimentaires de Viande. Rev. d'Hyg., 1900, pp. 782- 
792. 

Weitzel, a. Ueber die Labgerinnung der Kuhmilch unter dem Einfluss von Borpra- 
paraten und anderen chemischen Stoffen. Arbeiten aus dem kaiserlichen 
Gesundheitsamte, Bd. 90, Part i, 1902, p. 126. 

Report of the Departmental Committee appointed to Inquire into the Use of 
Preservatives and Coloring Matters in the Preserving and Coloring of Food. 497 
pp. London. 



CHAPTER XVIII. 
ARTIFICIAL SWEETENERS. 

Under this head are included the intensely sweet coal-tar derivatives, 
such as saccharin, dulcin, and glucin, that possess no food value whatever 
in themselves. From their high sweetening power, in some cases several 
hundred times that of cane sugar, they are capable, when used in minute 
quantity, of imparting an appropriate degree of sweetness to food products, 
which, on account of the use of inferior materials, or by reason of the 
presence of inert or less sweet adulterants, would otherwise be lacking 
in this property. 

Such canned vegetables as sweet corn and peas are subject to treat- 
ment with saccharin, especially if by their age and condition before can- 
ning they are wanting in the sweet, succulent taste inherent in the fresh 
product. 

The sweetening power of commercial glucose is considerably less 
than that of cane sugar, so that when large admixtures of the glucose are 
used in such products as jellies, jams, honey, molasses, maple syrup, 
etc., to the exclusion of cane sugar, the presence of the glucose might in 
some cases be suggested by the bland taste of the food, unless reinforced 
by one of the artificial sweeteners. 

The analyst should. therefore be on the outlook for one or another 
of these concentrated sweetening agents in all of the above classes of 
foods, especially in saccharine products wherein glucose is found to pre- 
dominate largely over the cane sugar, while the taste is not lacking in 
sweetness. It is doubtful how far the presence of artificial sweeteners 
can be regarded as a form of adulteration, unless their presence is legally 
and specifically prohibited. 

SACCHARIN. 

Saccharin or Gluside, Benzoyl sulphimide (CeH^.CO.SOjNH), is a 

white powder, composed of irregular cr)'stals, whose melting-point, when 

682 



ARTIFICIAL SIVEETENERS. 683 

pure, is about 224° C. It is prepared from toluene, which by treatment 
with concentrated sulphuric acid is first converted into a mixture of 
ortho- and para-toluene sulphonic acids. These are further converted into 
corresponding chlorides, and from the orthochloride, by treatment with 
ammonia, the imide is formed. It is soluble in 230 parts of cold water, 
30 parts of alcohol, and 3 parts of ether. It is sparingly soluble in chloro- 
form, but readily soluble in dilute ammonia. It is from 300 to 500 times as 
sweet as cane sugar, and, unlike cane sugar, it is not, when pure, charred 
by the action of concentrated sulphuric acid even on heating. Its aque- 
ous solution is distinctly acid in reaction. Pure saccharin, when heated 
under diminished pressure, can be sublimed without decomposition. 

The addition of i part of saccharin to 1,000 parts of commercial 
glucose renders the latter as sweet as cane sugar. 

A sodium salt of saccharin is found on the market, prepared by neutral- 
izing a solution of saccharin with sodium hydroxide or carbonate. The 
sodium salt crj'stallizes in the form of rhombic plates, forming a white 
powder readily soluble in water, and possessing nearly the same sweeten- 
ing power as saccharin. It is sometimes put up in the form of tablets 
for the use of diabetic patients as a substitute for sugar. 

Saccharin, aside from its sweet taste possesses, according to Fahlberg 
and List,* antiseptic properties, and on this account it is sometimes used 
in beer and other liquors. Squibb states that saccharin has about the 
same power as boric acid as an antiferment 

Detection of Saccharin in Foods. — If the sample to be tested is a solu- 
tion or syrup, render it acid, if not already such, with phosphoric acid, 
and extract with ether. In case of canned vegetables and similar goods, 
finely divide the material by pulping or maceration in a mortar, dilute 
with water, and strain through muslin. Acidify the filtrate, and extract 
with ether.f If an emulsion forms, use a centrifugal machine (p. 23). 
Separate the extract, evaporate off the ether, and test the residue for 
saccharin as follows : 

(i) Add to the residue, if it tastes sweet, a few cubic centimeters of 
hot water^ or preferably a very dilute solution of sodium carbonate, in 
which saccharin is more soluble. An intensely sweet taste is indicative 
of its presence. This test, if applied directly, will sometimes fail, espe- 
cially in the case of beer, by reason of the extraction by the ether of various 

* Jour. Soc. Chem. Ind., IV, p. 608. 

t Allen states that a purer residue is obtained if the sample of beer be treated with lead 
acetate, and filtered before extraction with ether. 



684 FOOD INSPECTION AND ANALYSIS. 

bitter principles, such as hop resins, which by their strong, bitter taste 
mask the sweet taste of saccharin in the residue. Spaeth * recommends 
that such bitter substances be removed before extraction, which is done 
by treatment of 500 cc. of the beer with a few crystals of copper nitrate, 
or with a solution of copper sulphate. The flocculent precipitate formed 
need not be filtered off, but the liquid is preferably concentrated by evap- 
oration to syrupy consistency, acidified with phosphoric acid, and ex- 
tracted with three successive portions of a mixture of ether and petro- 
leum ether. After extraction, separation, and evaporation of the solvent, 
dissolve the residue in weak sodium carbonate. As small a quantity 
as 0.001% of saccharin can be detected in the final alkaline solution by 
its sweet taste. 

(2) Bornslein's Test.'\ — Heat the residue from the ether extraction 
of the acidified sample with resorcin and a few drops of sulphuric acid 
in a test-tube till it begins to swell up. Remove from the flame, and, 
after cooling till the action quiets down, again heat, repeating the heating 
and cooling several times. Finally cool, dilute with water, and neutralize 
with sodium hydroxide. A red-green fluorescence indicates saccharin. 
Gantter I states that it is useless to apply this test to beer, m view of the 
fact that ordinary hop resin gives the same fluorescence. 

(3) Schmidt's Test.^ — The residue is heated in a porcelain dish with 
about a gram of sodium hydroxide || for half an hour at a temperature 
of 250° C, cither in an air-oven or in a linseed oil bath. This converts 
the saccharin if present into sodium salicylate. Dissolve the fused mass 
in water, acidify, and extract the solution with ether. Test the ether 
residue in the regular manner for salicylic acid with ferric chloride 
(p. 672). This test can obviously be applied only in the absence of 
salicylic 'acid, which should first be directly tested for. 

It is recommended that a mixture of equal parts of ether and petroleum- 
ether is preferable to the use of ether alone as a solvent of saccharin, as 
such a mixture, while readily dissolving saccharin, does not, like ether, 
dissolve other substances, which might form salicylic acid when fused 
with sodium hydroxide. 

Determination of Saccharin. — When saccharin is fused with an alkali 
and potassium nitrate, the sulphur is oxidized to sulphuric acid. On 

* Zeits. angewandte Chem., 1893, p. 579. 

tZeits. anal. Chem., 27, p. 165. 

t Ibid., 32, 309. 

§ Rep. Anal. Chem., 30; Abs. Analyst, 12, p. 200. 

11 Potassium hydro-xide cannot be used instead of sodium hydroxide for the fusion. 



ARTIFICUL SIVEETENERS. 685 

this principle depends the following method of Reischauer:* A known 
quantity of the beer or other liquid to be tested is concentrated by evapo- 
ration to about one-third its original volume, acidified with phosphoric 
acid, and extracted by repeated portions of ether. The combined ether 
extract is evaporated to small volume, and transferred to a platinum 
crucible, in which it is further brought to drj'ness. It is then cautiously 
ignited with a mixture of about 6 parts sodium carbonate and i part potas- 
sium nitrate. Dissolve the fusion in water, acidulate with hydrochloric 
acid, and determine the sulphuric acid in the usual manner with barium 
chloride. The weight of the precipitated barium sulphate, multiplied 
by 0.785, gives the weight of saccharin. In view of the fact that only 
small quantities of saccharin are used in beer and other foods, it is best 
to employ a large portion of the sample for analysis. 

DULCIN. 

Dulcin or sucrol, para-phenetol carbamide (C2H5O.CeH4.NH.CO.NH2) 

is a white powder, composed of needle-like crj'stals, sparingly soluble 
in cold water, ether, petroleum ether, and chloroform. It dissolves in 
800 parts of cold water, 50 parts of boiling water, and 25 parts of 95% 
alcohol. It is readily soluble in acetic ether. Its melting-point is about 
173° C. It is not readily sublimed without decomposition. Dulcin is 
about four hundred times sweeter than cane sugar. 

When a mixture of dulcin and dilute sodium hydroxide is subjected to 
distillation, phenetidin goes over with the steam into the distillate. When 
this is heated with glacial acetic acid, phenacetin is formed, which may 
be tested for as follows: Boil with hydrochloric acid, dilute whh water, 
cool, filter if turbid, and add a few drops of a solution of chromic acid. 
A deep-red color indicates phenacetin. 

Detection of Dulcin in Foods. — In view of the comparatively slight 
solubility of dulcin in ether and chloroform, acetic ether is the best solvent 
for purposes of removing it from foods, first making it alkaline. 

(i) Bellier^s Method.^ — A portion of the sample to be tested is made 
alkaline and extracted with acetic ether. In the case of certain products 
it is best to subject them to varied preliminary treatment, depending on 
the case in hand. With such products as thin fruit syrups, simply make 
alkaline and shake out with acetic ether. In the case of thick fruit syrups, 
confectionery, and preserves, dilute with water, add an excess of basic 

* Abst. Analyst, 11, p. 234. 

t Ann. de Chim. Anal., 1900, V, pp. m-^iy ; Abs. Analyst, 26, p. 43. 



686 FOOD INSPECTION AND /IN A LYSIS. 

lead acetate, remove the lead by precipitation with sodium sulphate, 
filter, and make the filtrate alkaline. 

With wines, add 2 grams of mercuric acetate and a slight excess of 
ammonia, shake, and filter. 

With beer, add to 200 cc. 2 or 3 grams of powdered sodium phospho- 
tungstate, and a few drops of sulphuric acid, sliake, allow to stand for a 
few minutes, and filter. Make the filtrate alkaline with ammonia. 

Having thus obtained a clarified solution, use from 50 to 200 cc. of 
neutral acetic ether to say 500 cc. of the alkaline solution, and shake 
in a separatory funnel. Separate the extract, filter, and evaporate to 
dryness. If the dulcin exceeds 0.04 gram per liter, crystals will be appar- 
ent in the residue. If fats and resins are present in the residue, make 
repeated extractions with hot water, and evaporate to dryness. The 
purified residue is finally brought to dryness in a porcelain dish, and 
treated with i or 2 cc. of sulphuric acid and a few drops of a solution 
of formaldehyde. Let it stand for fifteen minutes, and afterwards dilute 
with 5 cc. of water. A turbidity or precipitate indicates dulcin. 

(2) Jorissen's res/.*— The residue from the acetic ether extract of 
an alkaline solution of the sample is treated with 2 or 3 cc. of boiling 
water in a test-tube, and a few drops of mercuric nitrate | are added. 
Heat the tube and its contents for five minutes in a boiling water-bath, 
withdraw, and disregarding any precipitate, add a small quantity of lead 
peroxide. On the subsidence of the precipitate, which quickly occurs, 
a fine violet color appears for a short time in the clear upper layer in 
presence of o.ooi gram of dulcin. 

(3) M or pur go's Method.X — To the acetic ether residue, evaporated to 
dryness in a porcelain dish, add a few drops of phenol and concentrated 
sulphuric acid, and heat a few minutes on the water-bath. After cooling, 
transfer to a test-tube, and with the least possible mixing pour ammonia 
or sodium hydroxide over the surface. A blue zone at the plane of con- 
tact between the two layers indicates dulcin. 

Determination of Dulcin. — For a quantitative determination, Bellier's 
method is carried out on a weighed or measured portion of the sample, 
as follows: In the case of alcoholic beverages first expel the alcohol by 

* Chem. Zeit. Rep., 1896, p. 114. 

t The mercuric nitrate is prepared by dissolving 2 grams of mercuric o.xide in dilute 
nitric acid, adding sodium hydroxide solution till a slight permanent precipitate is formed, 
diluting to 15 cc, and decanting the clear liquid. 

t Zeits. anal. Chem., 1896, 35, p. 104; U. S. Dept. of Agric, Bur. of Chem., Bui. 65, 
p. 89. 



ARTIFICIAL SIVEETENERS. 687 

evaporation, and make up to the original volume with water. Treat 
the various food preparations with the appropriate clarifying reagents, 
as in Bellier's qualitative test (p. 685), and, after filtering and making 
alkaline, extract twice with 50 cc. each of acetic ether. The residue 
is purified if necessary by extraction with hot water as above described, 
and the final residue is dissolved in i to 5 cc. of concentrated sulphuric 
acid. A few drops of formaldehyde are added. The solution is allowed 
to stand for fifteen minutes, and then diluted to ten times its volume 
with distilled water. After twenty-four hours, collect the precipitate on a 
tared filter, wash with water, dry, and weigh. 

GLUCIN. 

This comparatively new sweetening agent is the sodium salt of a 
mixture of the mono- and di-sulphonic acids of a substance having the 
composition CjgHieN^. In the market it appears as a light-brown powder, 
readily soluble in water. It is insoluble in ether and cliloroform. It 
decomposes without melting at about 250° C. It is three hundred times 
sweeter than cane sugar. 

A color reaction with glucin is obtained by dissolving it in dilute 
hydrochloric acid, cooling by immersing the test-tube in water, and to 
the cold solution adding a little sodium nitrite solution. Finally, to the 
liquid is added a few drops of an alkaline solution of beta-naphthol, and 
a red coloration is produced. With resorcin or salicylic acid in alkaline 
solution, the color will be yellow. 

REFERENCES ON ARTIFICIAL SWEETENERS. 

Allen, A. H. The Detection of Saccharin in Beer. Analyst, 13 (1888), p. 105. 
Bellier, J. The Detection and Estimation of Dulcin in Beverages. Ann. de Chem. 

Anal., 1900, 5, 333; Abs. Analyst, 26, 1901, p. 43. 
Berlioz, F. Influence of Saccharin upon Digestion. Chem. Zeit., 1900, p. 416; 

Abs. Arialyst, 25, 1900, p. 233. 
BucHKA, K. V. Kunstliche SUssstoffe. Vereinbarung. v. Nahr. u. Genuss. f. d. deuts. 

Reich., Heft II, p. 134. Berlin, 1899. 
CoHN, G. Ueber kunstliche Siissstoffe. .^poth. Ztg., 1898, 13, pp. 796 and 804. 
Defournel, H. Determination of Saccharin in Food Products. Abs. Analyst, 26, 

1 90 1, p. 268. 
Dennhardt. Versuche zum Nachweise des Dulcins. Ber. d. deutsch. pharm. Ges., 

1898, 6, p. 287. 
Gantter, F. The Detection of Saccharin in Beer. Abs. Analyst, 18, 1893, p. 184. 
Gravill, E. D. Notes on Saccharin. Pharm. Jour., 8, 1887 (3), pp. 18, 337. 



688 FOOD INSPECTION AND /tN A LYSIS. 

Herzfeld, a., and Wolff, F. Ueber die Bestimmung der kiinstlichen Susssto£Fe in 

Nahrungsmitteln. Zeits. f. Unters. d. Nahr. u. Genussm., 1898, i, p. 839. 
JoRissEN, A. Neue Methode zum Nachweise von Dulcin in Getranken. Jour, de 

Phann. de Lifege; Chem. Centr., 1896, i, p. 1084; Abs. Analyst, 21, 1896, p. 164. 
Leys, A. A New Test for Saccharin. Ann. de. Chim. anal., 1901, 6, p. 201; Abs. 

Analyst, 26, 1901, p. 321. 
Reid, E. E. Valuation of Saccharin. Am. Chem. Jour., 1899, 21, p. 461. 
RuGER, C. Ueber das Fahlberg'sche Saccharin. Gesundheit, 1888, 13, p. 241. 
SCHMITT, C. Ueber den Nachweis der o. Sulfamin-benzoesauer, genannt "Fahl- 

berg'sches Saccharin." Rep. fiir anal. Ch., 1887, 7, p. 437. 
Spath, E. Ueber den Nachweis des Saccharins im Bier. Zeits. f. angew. Chemie, 

1893. P- 579- 
Sutherland, D. A. Saccharin. Jour. Soc. Chem. Ind., 6, 1887, p. 808. 
Taylor, W. A. H. Commercial Saccharine. Pharm. Jour., 1887, 88 (3), 18, 377. 
Thoms, H. Ueber Dulcin. Ber. d. deutsch. pharm. Gesellsch., 1893, 3, 133. 
Wanters, J. Nachweis des Saccharins im Bier. Moniteur scientifique, 4, 1896, 10, 

146. 



{ 



CHAPTER XIX. 

CANNED AND BOTTLED VEGETABLES, RELISHES, AND FRUIT 

PRODUCTS. 

CANNED VEGETABLES AND FRUITS. 

Strictly speaking all varieties of canned foods found in the market, 
whether meats, fruits, or vegetables, in order to be entirely beyond criti- 
cism, should not differ from the corresponding freshly cooked varieties 
which they are intended to replace, excepting that they are free from 
bacteria. Such a degree of perfection is, however, difficult, even if pos- 
sible, to attain, and nearly all commercial canned products, even if made 
from the best materials, are liable to contain either antiseptic substances 
or coloring-matter intentionally added by the manufacturer, or metallic 
impurities accidentally derived from the vessels in which they are pre- 
pared, or from the containers in which they are sealed. In spite of these 
objections, canned foods form a convenient, and in some cases indispensa- 
ble means of furnishing both necessities and luxuries for the table. The 
canning of foods is especially useful for preserving them during long 
periods of time, for enabling certain fruits and vegetables to be enjoyed 
out of season, and for furnishing supplies in a, convenient manner to inac- 
cessible places where fresh foods are not readily obtainable, as in the 
case of armies in the field, of vessels at sea, of campers in the woods, etc. 
Canned goods in great variety are used in nearly every household. 

When it is considered that in the United States alone something like 
one hundred million cans of corn are packed in a single year, about the 
same quantity of peas, and one hundred and fifty million cans of tomatoes, 
to say nothing of an ever-increasing variety of other foods, some idea may 
be gained of the enormous proportions to which the canning industry 
has grown. It is comforting to know that, in view of their wide-spread 
consumption, the greater portion of such foods found on the market are 

689 



690 FOOD INSPECTION AND ANALYSIS. 

comparatively harmless, as is evidenced by the fact that few cases of injury 
to health have been directly traceable to their use. 

Method of Canning Food. — Various modifications as to details exist 
with different products and in different localities, but in general the prin- 
ciple of canning in tin is the same in all cases. The fresh product is 
cleaned carefully, and packed in cans with the requisite amount of water. 
The cans are then sealed, and subjected to the effect of steam or boiling 
water till the contents are thoroughly cooked. Each can is then tapped 
or punctured at one end to expel the air, and again heated, after which 
the hole is closed by a lump of solder, thus forming a vacuum in the can, 
which is afterwards heated for a sufficient time to destroy the bacteria, 
usually for several hours. 

The above mode of procedure is the time-honored one, and is still in 
vogue in most localities, but a more modern method, much in use at present, 
consists in first cooking the food at a temperature of 82° to 88° C. before 
transferring to the cans, and afterwards subjecting the cans when sealed 
to a high heat of about 125° C. in dry air in so-called retorts, this heating 
or "processing," as it is termed, being carried on for a sufficient length 
of time to completely sterilize the contents of the can. Obviously a much 
shorter time is required for this than when the temperature of boiling 
water is employed, and the sterilization is much more effective. 

Cooked vegetables and fruit products put up in glass jars or bottles 
are tightly sealed when hot, either with screw-caps or with some form of 
cover held by a clamp, or with metal or hard-rubber caps fitting over a 
flanged mouth. Frequently a soft-rubber ring is inserted between the 
cover and the mouth of the jar or bottle. The material of the cover is 
generally either glass, porcelain, or metal. Cork stoppers are, however, 
sometimes pressed into the mouths of the bottles, and made extra tight 
therein with sealing-wax. These stoppers are occasionally soaked in 
paraffin. Thus the contents of the jar may be exposed to porcelain, 
glass, metal, rubber, or cork, according to the material of the cover and 
the method of sealing. 

The preservation of food by canning was long thought to be due to 
the perfect exclusion of air, but is now known to depend on the perfect 
sterilization, or destruction of bacteria, and it has been proved that as 
far as keeping qualities are concerned, it makes no difference whether 
or not air is present m the can, if the contents are sterile, though for pur- 
poses of inspection the vacuum, in the case of tin cans, is of great use, in 
that as a natural consequence of the vacuum, when the goods are sound, 



CANNED AND BOTTLED (VEGETABLES, ETC. 



691 



the ends of the can are usually concave. The highest aim of the canner 
should be to retain in his product as far as possible the appearance, pala- 
tability, and nutritive value of the freshly cooked food. 

PROXIMATE COMPOSITION OF CANNED VEGETABLES AND FRUITS* 



CANNED VEGETABLES. 

Artichokes 

Asparagus 

Beans, baked 

' ' string 

' ' Lima 

Brussels sprouts 

Corn, green 

Peas, green 

Pumpkin 

Squash 

Succotash 

Tomatoes 

CANNED FRUITS. 

Apples, crab 

Apple sauce 

Apricots 

Blackberries 

Blueberries 

Cherries 

Peaches 

Pears 

Pineapples 

Strawberries 



« 








>. 
















■At 


•O.S 




& 


e 




^0-3 


^E 


< 


3 


92-s 


.8 




s-° 


.6 


1-7 


14 


94-4 


1-5 


. I 


2.8 




5 


1.2 


21 


68.9 


6.9 


2-5 


19.6 


2 


5 


2. 1 


29 


93-7 


i-i 


.1 


3-8 




5 


1-3 


16 


79-5 


4.0 


-3 


14.6 


I 


2 


1.6 


r 


93-7 


1-5 


.1 


3-4 




5 


1-3 


52 


76.1 


2.8 


1.2 


19.0 




8 


■9 


88 


8s-3 


,V6 


.2 


9.8 


I 


2 


I.I 


7 


91.6 


.8 


_ 2 


6.7 


I 


I 


-7 


5 


87.6 


-9 


-5 


10.5 




7 


•5 


12 


75-9 


3-6 


I.O 


18.6 




9 


-9 


19 


94.0 


1.2 


.2 


4.0 




5 


.6 


I 


42.4 
61. 1 


-3 


2-4 


54-4 
37-2 
17-3 
56-4 
12.8 




.5 
-7 
.4 
•7 
.4 
•5 
-3 
•3 
-7 
•5 




.8 




I 


81.4 


•9 
.8 








40.0 
8=;. 6 






3 

I 


.6 


.6 




77-2 
88.1 


I.I 


.1 






3 
4 


•7 
-3 
.4 




10.8 




81. 1 


-3 

-7 


18.0 




I 


61.8 


36.4 
24.0 




I 


74-8 


•7 









> a 



85 

600 

95 
360 

95 
455 
255 
15° 
23s 
455 
105 



1,120 
730 
340 

I1I50 
275 
415 
220 

355 
715 
460 



*U. S. Dept. of Agric. Exp. Sta. Bui. 28, p. 70. 

Methods of Proximate Analysis. — As a rule, the contents of canned 
goods are intended to be entirely edible throughout, and contain little 
or no refuse or portions to be rejected. An exception to this is the occa- 
sional canning of certain fruits with stones or pit's, which are, of course, 
to be removed. The can or package is first weighed before opening, and 
later the cleaned receptacle is weighed after its contents have been removed. 
The weight of the contents is thus ascertained by difference. 

For the analytical determinations, the contents of the can or bottle 
are intimately mixed to form a homogeneous pulp, so that parts taken 
for analysis are fairly representative of the whole. If considerable liquid 
is present, with some solid masses held in suspension therein, the liquid 
is best drained off, and the solid portions pulped separately in any con- 
venient manner, as by the use of a mortar, or by means of a household 



692 FOOD INSPECTION AND ANALYSIS. 

food-chopper. The whole is then thoroughly mingled together. If 
desired, the weight of the liquid and solid portions may be separately 
ascertained before mixing. 

The analyst should use judgment and discrimination as to how 
various portions of the mass are to be best measured out for the deter- 
minations. Much depends on the consistency of the pulpy mass. It 
is often convenient to make a 20% solution or mixture of the material 
with water, usmg say 50 grams of the pulped sample in 250 cc. of water, 
such of the sample as is insoluble being disintegrated by shaking. 

Methods for determining water, ether extract, crude fiber, protein, 
and ash do not differ materially from those employed in the case of cor- 
responding fresh fruits and vegetables. 

These determinations, in the case of canned products, while useful 
in showing their food value, give little information as to their adulteration 
by the substitution of foreign vegetable or fruit pulp. 

Accidental Impurities. — Under this head are included (i) products 
of decomposition, due to the incomplete sterilization of the contents of 
the can, and (2) metallic salts due to the solvent action of the juices of the 
contents on the inner surface of the can, or of the vessel in which the 
product has been previously cooked. 

Decomposition, and the Detection of Spoiled Cans. — In the case of 
canned vegetable products, decomposition rarely rcsuhs in the formation 
of ptomaines even after the can has long been open, though these toxins 
are sometimes formed, in canned meat and fish. Decomposition is readily 
apparent after opening a can, from a cursory examination of its contents. 
The appearance, taste, and odor will not fail to indicate the unfitness 
of the contents for food, if decomposition is at all advanced. It is, how- 
ever, often of great advantage to detect spoiled cans without opening. 
As a rule, when a can. is spoiled, it is usually in the condi.ion termed 
"blown," i.e., with its ends convex, instead of normal or concave. 

According to Prescott and Underwood,* although nearly all forms of 
bacterial decomposhion are accompanied by bulging of the ends of the 
cans, there are some exceptions. In the souring of canned sweet corn,t 
for instance, it is exceptional that swelling occurs. Ordinarily, in the 
factory inspection of canned goods before shipping, not only are the 
bulged cans or "swells," as they are termed, sifted out, but the condition 



* Tech. Quart., 11, 1S98, pp. 6-30; also lo, 1897, p. 183. 

t These experimenters found at least twelve varieties of bacteria to which the souring of 
corn is apparently due. 



CANNED AND BOTTLED VEGETABLES, ETC. 



693 



of the cans is tested by sounding or striking the cans. If the contents 
are sweet, a peculiar note is produced when the can is struck, readily 
distinguishable from the dull tone of the unsound can by any one familiar 
with the work. 

As stated above, concavity in the ends of the can indicates that the 
contents are in good condition. 

Prescott and Underwood further state that sound cans may be dis- 
tinguished from unsound in a lot of suspicious goods, when the swelling 
of the ends is not apparent, by the following method: 

Boil the cans for an hour, causing the ends of all to swell, then cool, 
and set aside for eight hours, during which the sound cans will snap back, 
while the unsound will continue convex, by reason of the fact that the 
sweUing in tliis case is due to the generation of gas by the bacteria 
present. 

Examination of Gases from Spoiled Cans. — When the tops of blown 
cans are punctured in the process of opening, an outflow of gas is usually 
to be noted. Doremus * has studied the character of these gases and 




Fig. iiS. — Apparatus for Collecting Gases from Spoiled Cans. (After Doremus.) 

found that when the contents have become putrid, carbon dioxide and 

hydrogen are the chief gases to be found. Often 60 to 80 cc. of gas 

may be collected from a can. For the collection of the gases, Doremus 

* Jour. Am. Chem. Soc, 19, 1897, p. 733. 



694 FOOD INSPECTION AND ANALYSIS. 

uses the device shown in Fig. ii8. An adjustable clamp has attached 
to its upper arm a beveled, hollow, steel needle. A perforated rubber 
stopper covers the needle and serves as a cushion. A fine tube 
connects the needle with the receiver of a eudiometer, both tube and 
receiver being filled with water or mercury. Either the stop-cock form 
of eudiometer, as here shown, or the kind with attached leveling-tube 
may be used. The can is adjusted between the arms of the clamp, 
and by turning the screw the needle is brought into contact with the 
top of the can and caused to puncture it, the rubber stopper serving 
to make a gas-tight joint. The gas passes through the tube into the 
eudiometer, and its constituents are determined in the usual manner, 
either by introducing the reagents directly into the eudiometer-tube in 
the proper order, or by transferring the gases to pipettes.* Hydrogen 
sulphide is tested for by subjecting a filter-paper moistened with lead 
acetate solution to the gas. If it turns black, the presence of hydrogen 
sulphide is indicated. 

METALLIC IMPURITIES. 

Salts of Lead and Tin are commonly met with in varying amounts 
in nearly all classes of products put up in tin. The quantity dissolved 
depends, largely on the character of the tin plate used in the manufacture 
of the can, as well as on how the solder is applied. Much depends 
also on the nature of the food product and its acidity. Formerly 
much danger was apprehended from the use of the so-called terne plate 
as a material for cans. This consists of an alloy of lead and tin, 
coated on iron plate and intended for use as roofing. Sometimes two 
parts of lead to one part of tin are found in terne plate. Only the better 
grades of bright tin plate should be used in canning. There is reason 
to believe that no terne plate is at present used in cans. In 1892 the 
plating alloy of 47 samples of tin cans in which peas had been put 
up were examined in the Bureau of Chemistry of the U. S. Department 
of Agriculture, f and the amount of lead found varied from o to 13 per 
cent. Only 4 samples were found to exceed 5 per cent, and 24 contained 
less than i per cent. 

The construction of the can should be such that practically no soldered 
surface is exposed to the contents, the joints being lapped and soldered 
on the outside. In spite of this, however, it is not unusual to find cans 

* See Thorpe's Dictionary of App'd Chem., Vol. i, pp. 159-161. 
t Bui. 13, p. 1036. 



C/INNED AND BOTTLED VEGETABLES, ETC. 



69s 



in which the contents have access to the solder, and it is common 
to find himps of solder in the can from the final sealing of the tapped 
hole in the top. The amount of lead in 24 samples of solder 
taken from the interior of some of the cans mentioned in the pre- 
ceding paragraph, was found to vary between the limits of 51 and 65 
per cent.* 

Action of Fruits and Vegetables on Tin Plate. — The amount of tin 
dissolved by various canned fruits and vegetables is roughly indicated by 
the corrosion of the inner surface of the can. A large variety of these 
canned products have been examined in the laboratory of the Massachu- 




/ 



Fig. 119. — Interior of Blueberry Cans, Cut Open to Show the Corrosion by Acid of the 

Fruit Juice. 

setts State Board of Health, with a view to determining the quantity of 
tin contained in solution. The results have shown that though notable 
traces of tin were found in acid fruits and rhubarb, and large traces in 
some green vegetables, canned blueberries were found to contain, as a 
rule, much more tin in solution than any other canned goods examined. 
It is assumed that the tin was, at least in considerable part, still held in 
solution by the fruit acids, inasmuch as tlie metal was found in the filtered 
juice. In every instance the inner tin lining was found to be exten- 
sively corroded, and in some cases it had been almost entirely dis- 
solved off, leaving the underlying iron bare. Fig. 119 shows the appear- 

* Bui. 13, p. 1038. 



696 



FOOD INSPECTION AND ANALYSIS. 



ance of one of these cans, split open to show ils inner surfaces. The 
corrosion is apparent. Eleven samples of canned blueberries, represent- 
ing seven brands, were examined in 1894 by Worcester, showing an amount 
of tin in solution (calculated as SnOj) varying from 0.066 to 0.27 gram 
per can of 615 cc. capacity. 

In 1899 samples of various canned products were examined for lead 
and tin in the author's laboratory, the results of which are thus summar- 
ized : * 



Tin, Grams. 


Lead, Grams. 


Capacity of 
Can, cc. 






615 


-0393 


.0004 




.0124 


.0000 


615 


.0848 


.0002 




-0725 


.0001 


61S 


.2226 


.0021 




.0056 


.0004 


950 


-0515 


.0004 




.0146 


.0001 


650 


-0499 


.0003 




.0065 


.0008 


61S 


.0046 


. 0000 




.0024 


.0001 


61S 


.0101 


-ooir 




.0045 


.0001 




.0064 


.0004 


650 


.0039 


-OOOI 


650 
95° 


■1793 


.0087 




■1577 


.0003 




.1844 


.0019 


950 


•35°6 


.0002 


61S 


.1249 


.0001 


93° 


.0114 


.0001 


95° 


.0023 


.0002 


37° 


•0319 


.0001 


47° 


.0411 


.0001 


430 



Strawberries. . 

Highest. . . , 

Lowest. . . . . 
Raspberries. .. 

Highest. . . . 

Lowest. . . . . 
Blueberries. . 

Highest. . . . 

Lowest. ... 
Tomatoes 

Highest. . . 

Lowest. . . . 
String beans. 

Highest. . . 

Lowest. . . . 
Peas 

Highest. . . 

Lowest. . . . 
Corn 

Highest. . . 

Lowest. . - . 
Lima beans. . 
Succotash. . . 
Sciuash 

Highest. . . 

Lowest. . . . 
Pumpkin. . . . 
Rhubarb. . . - 
.•\sparagus. . . 
Mutton broth 
Tomato soup 

Salmon 

Lobster 



A wide range of variation exists in the amount of tin dissolved by 
various fruits. In the case of pumpkin and squash, for example, the 
tin dissolved is surprisingly large in quantity, considering the supposed 
inert nature of these vegetables. 

Samples of canned sardines put up in mustard, vinegar, and oil have 



* An. Rep. Mass. State Board of Health, 1899, p. 623. 



CANNED AND BOTTLED yECETABLES, ETC. 



697 



also been examined by the Massachusetts Board, and found to be high 
in tin. The highest figures showed 0.376 gram (expressed as metaUic 
tin) in a half-pound can. In these cases the corrosion of the interior 
of the cans was very marked. 

Effect of Time on Amount of Tin Dissolved. — A series of experi- 
ments was conducted by the author in 1899 * on the action of various 
fruit acids on tin, with a view to ascertaining, among other facts, whether 
or not the element of time exerts an appreciable difference in the resuhs. 

Samples of various canned fruits and vegetables were titrated for 
their acidity. It was found that certain samples of canned blueberries, 
for instance, had an acidity of about one-twentieth normal. In the case 
of strawberries, the acidity was about one-sixth normal. Canned rasp- 
berries were found to be about one-tenth normal in acidity, while the 
acidity of canned tomatoes varied from one-tenth to one-fourteenth normal. 
Solutions of one-fifth, one-tenth, and one-fifteenth-normal mahc acid, 
one-tenth and one-fifteenth-normal tartaric acid, one-tenth and one- 
fifteenth-normal citric acid, and one-tenth-normal acetic acid were 
prepared and sealed in pint glass jars, having about the same capacity 
as the ordinary-sized tin fruit cans, each jar containing an amount of 
tin plate equivalent to the interior exposed surface of a can. Solutions 
thus sealed were kept for three months, six months, and a year, and 
examined at the end of these respective periods for tin. The results 
showing the amount of tin found at the end of three months in each 
case are given in the following list: 



ACTION OF FRUIT ACIDS ON TIN IN THREE MONTHS. 



Acid. 


Grams of Tin 

in One Pint of 

Solution. 


Acid. 


Grams of Tin 

in One Pint of 

Solution. 


N/5 malic 


0.0578 
0.0201 
0.0197 
0.0382 


N/if^ tartaric 


0.0246 
0.0374 
0.0236 
0.0019 


N/io " 




N/i>; " 


N/it; " 











It was found, in general, that the amount of tin dissolved in three 
months, as indicated above, was the maximum amount dissolved, or, 
in other words, with a very few exceptions no additional tin was dissolved 
by added exposure to the acid for six months, or even a year. The 

* An. Rep. Mass. State Board of Health, 1899, p. 624. 



OgS 



FOOD INSPECTION AND ANALYSIS. 



amount of tin dissolved was found to vary proportionally with the strength 
of acid, as would naturally be expected. 

Experiments with tenth-normal acetic acid (which was found to be 
the approximate acidity of the canned sardines mentioned on page 697), 
sealed in jars with tin plate, as in the case of the fruit acids, and kept 
for three and six months respectively, showed that in three months 0.0019 
gram, and in six months 0.0083 gram of metallic tin had been dissolved, 
indicating much less vigorous action than that of the same strength of 
fruit acids, and dissolving less tin than the samples of sardines examined. 

Salts of Lead. — While it is a fact that the material of the tin plating 
usually found in cans is comparatively low in lead, the same is not always 
true of the metal caps used to cover some of the bottled goods. The 
French "haricots verts "are usually sold in wide-mouthed bottles, closed 
by a disk of very soft metal. In one instance this metal cap, which came 
in contact with the liquid contents of the bottle, was found to contain 
93^% of lead. Of the various kinds of bottles in which are sold cheap 
carbonated drinks known as "pop," one style has a stopper consisting of 
a metallic button surrounded by a rubber ring. These metallic buttons 
consist of tin and lead in varying proportions. Inasmuch as the inclosed 
liquor was usually found to be quite acid in reaction, the danger of pro- 
longed contact with the metallic portion of the stopper is evident. 

The following table gives the percentage of lead found in the stoppers 
of this character, together with the amount of lead contained in the liquor: * 



Character of Sample. 


Per Cent of 
Lead in Stopper. 


Amount of Lead 
in Contents of 
Bottle in Milli- 
grams, t 


Blood orange 

Birch beer. ... . . . . . 


5° -7 
35-° 
32.2 
8.8 
6.5 
8-5 
3-5 
7-5 

50-3 
3-8 


0-3I 
Large trace 
0.40 
0.20 
0.30 
0.19 
0.17 
0.27 

I -OS 

O.OI 


Ginger 




SarsapariLla A 


Sarsaparilla B 




Miscellaneous (20 samples) 
Maximum , . . . . 







t Capacity of bottle about i pint. 



Besides the above tabulated samples, twenty were found with stoppers 
containing less than 3% of lead; While the amount of lead found in the 

* An. Rep. Mass. State Board of Health, 1897, p. 571. 



CANNED AND BOTTLED yEGETABLES, ETC. ■ 699 

contents of the bottles was in no case very large, it was enough to con- 
demn the use of lead in the manufacture of such stoppers. That 
the amounts of lead found in the contents of the bottles vary quite irre 
spective of the percentage of lead in their stoppers, may be ascribed to 
various causes, such as the difference in the acidity of the liquors, and 
the length of time that the liquor has been in contact with the stopper. 
Furthermore, the more soluble metal of an alloy is attacked by an acid 
with an energy which is not proportional to the percentage of that metal 
in the alloy. 

Salts of Zinc. — The presence of zinc salts in canned foods is largely 
accidental, and is generally due either to the contact of the acid fruits 
and vegetables with galvanized iron in the canneries, to the occasional 
use of brass vessels, or to the zinc chloride used as a soldering fluid. 
Hilgard and Colby * have examined empty tin cans fresh from the manu- 
facturer, and found zinc chloride in notable quantity in the seams, and 
especially in the empty space of the lap at the bottom of the can, where 
it could easily be acted on by the contents. The average amount of 
soluble zinc chloride found in the "lap" alone amounted to three- fourths 
of a grain per can. It was furthermore ascertained that it was not the 
practice of canners to wash the cans before packing, so that zinc present 
in canned goods may thus readily be accounted for. 

Zinc chloride is commonly used in machine soldering, but should be 
displaced by rosin. 

Hilgard and Colby found in some spoiled cans of asparagus, where 
the acidity was unusually high, an average of 6.3 grains of zinc chloride 
per large can. 

Zinc salts are said to have been used for greening peas, but their use 
for this purpose is not common. Zinc chloride is the salt used, and a 
natural yellowish-green tint is imparted when properly applied. The 
process has been kept secret. 

Salts of Copper. — While copper in canned goods is sometimes acci- 
dental, its presence being due to the use of copper or brass vessels in the 
canneries, its chief interest to the food analyst lies in the use of copper 
sulphate for greening peas and other vegetables. The artificial greening 
of vegetables is much more commonly practiced in France than in the 
United States. 

French canners of peas, beans, Brussels sprouts, etc., are frequently 
so lavish in the use of sulphate of copper that the goods as found on our 

* Rep. Cal. Agric. Exp. Sta., 1897-8, p. 159. 



700 FOOD INSPECTION AND /IN A LYSIS. 

markets can in some cases hardly be said to resemble the freshly cooked 
products in color. Oftentimes, indeed, they possess such a deep green 
as to be positively distasteful to the average American palate, though 
evidently this unnatural hue is craved in Europe. The use of copper 
in such foods is often rendered apparent by the most cursory examina- 
tion. 

In this country, when copper is used, smaller quantities are usually 
employed, with an attempt to imitate more closely the color of the natural 
product. 

Complaint in court for this form of adulteration under the general 
food law as it exists in most states would naturally be brought under one 
of two clauses : 

ist. As being colored, whereby the product appears of greater value 
than it really is, or 

2d. As containing an ingredient injurious to health. 

An ingenious claim is sometimes advanced by the defendant in oppo- 
sition to clause i, to the effect that copper sulphate is added, not to give 
an artificial green color, but to preserve the original green of the chloro- 
phyl or natural color of the fresh peas,* so that it will not be destroyed 
by subsequent boiling. 

This point was argued in a strongly contested court case brought in 
Massachusetts for copper in French peas.| 

As Worcester t has shown, the fallacy of this .argument can be easily 
demonstrated. If it were true that the copper acts as a preservative of 
the chlorophyl, a pure extract of chlorophyl should, by the addition of 
copper sulphate, be prevented from destruction on boiling, and again, 
on once destroying the color of the chlorophyl by boiling, it would be 
impossible to restore it by further boiling it with copper sulphate. 

As a matter of fact, if an extract of chlorophyl is boiled with a dilute 
solution of copper sulphate, its color is at once destroyed, and a brown 
precipitate is thrown down. On the other hand, if yellow or white peas 
or beans devoid of chlorophyl are boiled with copper sulphate, they are 
colored green, the depth of color depending on the strength of the copper 
solution. When peas or other vegetables are thus colored, very little 
copper is found, as a rule, in the liquid contents of the can, but the copper 
is chiefly confined to the solid portions. Green compounds are produced 

* The term used by the French to describe this process is reverdissage or " regreening. " 
t An. Rep. Mass. State Board of Health, 1892, p. 605. 
t Loc cit., supra, p. 641. 



CANNED AND BOTTLED yEGETABLES, ETC. "jot 

by boiling albumins with copper salts, due to the formation of albuminate, 
or in the case of peas, leguminate of copper. Harrington * states that it is 
possible to color eggs an intense green by boiling with copper sulphate. 

Examination of a large number of brands of canned vegetables greened 
by copper, as bought in Massachusetts, showed that the amount used 
varied from a trace to 2.75 grams per can, calculated as copper sulphate. 
In justice to the consumer, who may be cautious about taking into his 
system copper salts, as well as to those who are indifferent to their use, 
it is no more than fair that all cans should have a label, plainly stating 
the quantity present. In the Massachusetts market, labels like the fol- 
lowing are not uncommon: "This package of French Vegetables con- 
tains an equivalent of Metallic Copper not exceeding three-quarters of 
a grain." 

Copper as a coloring matter has been most commonly found in peas, 
beans, and Brussels sprouts. Copper salts in minute quantity have been 
found in Massachusetts in canned tomatoes, clams, and squash, as well 
as in pickles. 

Salts of Nickel. — Sulphate of nickel has been employed instead of 
sulphate of copper for greening vegetables. According to Harrington | 
0.25 gram of nickelous sulphate per kilogram of peas is used. The peas 
or other vegetables are boiled in a solution of the salt, made slightly alka- 
line with ammonia. 

Toxic Effects of Metallic Salts. — Divergence of opinion is so great 
as to the toxic effects of salts of the heavy metals on the human system, 
when present in the small amounts commonly found in food products, 
that it is extremely difficult to maintain a complaint in court based 
entirely on the harmful effects of these salts. Since the question is one 
for the toxicologist or physiological chemist rather than the analyst to 
settle, it will not be discussed here at length ; suffice it to say that a large 
number of experiments on human beings will undoubtedly have to be 
tried, before the necessary data will be at hand on which to base a really 
intelligent opinion. The same general difficulties are met with here as 
one encounters in the matter of determining the definite effects of anti- 
septics in food, of alum in baking-powder, etc. 

Determination of Lead in Tin Alloy. — Method oj Paris Municipal 
Lahoralory.X — The material, if soft, is hammered into a thin plate, and 

* Practical Hygiene, p. 203. 

t Ibid., p. 205. 

X Analyse des Matieres Alimentaires et Recherche de leurs Falsifications, 1894, p. 695. 



702 FOOD INSPECTION AND ANALYSIS. 

2\ grams are weighed out, transferred to a 250-cc. flask, and dissolved 
in 7 to 8 CO. of concentrated nitric acid. Evaporate to dryness on the 
sand-bath, add 10 drops of nitric acid and 50 cc. of boiling water, cool, 
and make up to 250 cc. with water. Let the residue settle and pour off 
through a filter 100 cc. of the clear, supernatant licjuid, corresponding 
to I gram of the material. This contains the lead, while the tin is left 
behind in the residue, together with antimony if present. 

Add 10 cc. of a standard solution of potassium bichromate (7.13 grams 
to the liter) and shake. Each cubic centimeter of this standard solution 
is sufficient to precipitate o.oi gram of lead. Allow the lead chromate 
formed to settle, and, if the solution is colorless, add 10 cc. more of the 
bichromate, or sufficient to be present in excess, as indicated by the yellow 
color. Filter, wash, and titrate the excess of bichromate with a standard 
iron solution, containing 57 grams of the double sulphate of iron and 
ammonia and 125 grams of sulphuric acid per liter. This iron solution 
should be kept under a layer of petroleum, and standardized against 
the potassium bichromate before use. 

Add, drop by drop, the iron solution to that containing the excess of 
bichromate. The color of the latter passes from pale green to bright 
green, when the chromate is completely reduced. Determine the end- 
point with a freshly prepared dilute solution of potassium ferricyanide, 
a drop of which is placed on a porcelain plate or tile in contact with a 
little of the solution titrated. A blue color is produced when the iron 
is present in excess. If the standard iron and bichromate solutions 
exactly correspond, i cc. of the iron solution is equivalent to 1% of lead, 
but the latter solution is usually a little weak. 

If w = number of cubic centimeters of iron solution necessary to 
reduce 10 cc. of the standard bichromate, 

I cc. of the iron solution = — . 

11 

If, now, r = number of cubic centimeters of iron solution necessary 
to reduce the excess of bichromate in the determination, and 5 = number 
of cubic centimeters of bichromate used, 

s r = per cent of lead in the alloy. 

Separation and Determination of Tin, Copper, Lead, and Zinc in 
Canned Goods. — Munson's Method.* — The contents of the can are 
* U. S. Dept. of Agric, Bur. of Chem., Bui. 6;, p. 52. 



C/INNED /1ND BOTTLED VEGETABLES, ETC. 703 

first evaporated to dry-ness, and from 10 to 15 cc. of concentrated sul- 
phuric acid or enough to carbonize are added to the dry residue contained 
in a porcelain evaporating-dish, which is very gently heated over the flame 
till foaming ceases. Then ignite to an ash in a muffle, or carefully over 
the free flame, using a little nitric acid, if necessary, for oxidation -of the 
organic matter. Add 20 cc. of dilute hydrochloric acid, and evaporate 
over the water-bath to dryness. Wash the residue into a beaker, slightly 
acidify with hydrochloric acid, and saturate with hydrogen sulphide 
without previous filtration. Heat the beaker on the water-bath, and 
pass the contents through a filter. Wash the precipitate, which contains 
sulphides of tin, lead, and copper, if these metals are present, while if there 
is zinc, it is contained in the filtrate. The precipitate is fused with sodium 
hydroxide in a silver crucible for half an hour, to increase the solubility 
of the tin, which would otherwise be dissolved with difficulty. The 
fusion is boiled up with hot water, acidulated with hydrochloric acid, and 
transferred without filtering to a beaker, in which hydrogen sulphide 
is added to saturation. This precipitates the sulphides of tin, lead, and 
copper (if these metals are present). The sulphide precipitate is collected 
on a filter, and thoroughly washed with hot water, the washings being 
rejected. Pass through the filter several portions of boiling ammonium 
sulphide, using about 50 cc. in all, or till all the tin is dissolved. Precipi- 
tate the tin from the combined filtrate with hydrochloric acid, filter, 
wash, ignite, and weigh as stannic oxide. 

The residue left on the filter, after dissolving out the tin sulphide, is 
then dissolved by treatment with nitric acid, which is filtered, and to 
the filtrate and washings ammonia is added nearly to the point of neutral- 
ization. Then add ammonium acetate. Filter off any precipitate of 
iron that may be formed. The filtrate is divided into two portions for 
determination of copper and lead. If lead is absent, determine the 
copper by titration with potassium cyanide * or electrolytically (p. 493). 
Copper is rarely present in sufficient amount to be determined, unless 
used for greening the vegetables. If notable quantities of lead are present, 
the solution is made acid with acetic, and the lead precipitated therefrom 
with potassium chromate, collected on a tared filter, washed with water 
acidified with acetic acid, dried at 100° C, and weighed as lead chromate. 
Or determine the lead by color-tests, as on page 704. 

For the determination of zinc, the filtrate from the first hydrogen- 
sulphide residue is evaporated to a volume of about 60 cc, and treated 

* Sutton, Volumetric Analysis, 8th ed., p. 204. 



704 FOOD INSPECTION AND ANALYSIS. 

with bromine water to oxidize the iron, as well as any excess of hydrogen 
sulphide remaining, the excess of bromine is then boiled off, and a few 
drops of concentrated ferric chloride added, to make the solution distinctly 
yellow, if not already so. Nearly neutralize with ammonia, and precipi- 
tate the iron with ammonium acetate. Filter, wash, acidify the filtrate 
with acetic acid, and precipitate the zinc with hydrogen sulphide. 
Filter, wash, ignite, and weigh as zinc oxide. 

The metals may be determined separately, as follows: 

Determination of Tin.* — Evaporate the contents of the can to dry- 
ness, and ignite in porcelain. Fuse the ash with sodium hydroxide in a 
silver crucible, boil the fusion with several portions of water acidulated 
with hydrochloric acid, filter, and precipitate the tin from the acid solu- 
tion with hydrogen sulphide. Dissolve the washed precipitate in ammo- 
nium sulphide, filter, and deposit the tin directly from this solution by 
electrolysis in the platinum dish which contains it, using a current of 
0.05 ampere and the electrolytic apparatus described on page 493. 

Determination of Lead, especially applicable if lead is present in small 
amounts only. Boil the sulphated ash of the contents of the can (obtained 
as on page 703) with a solution of ammonium acetate, having an excess of 
ammonia. The tin, zinc, and iron remain insoluble, while the copper 
and lead are dissolved. Filter, wash, and add a^ few drops of potassium 
cyanide to the filtrate, to prevent precipitation of copper when hydrogen 
sulphide is subsequently added. If the solution exceeds 40 cc, concen- 
trate to that amount by evaporation, and transfer to a 50-cc. Nessler 
tube. Add hydrogen sulphide water, and make up to the mark. Com- 
pare the brown color imparted by the lead sulphide, with the colors 
obtained by treating with hydrogen sulphide water in Nessler tubes 
various measured amounts of a standard solution of lead acetate, made 
alkaline with ammonia. 

Determination of Copper. — (i) Electrolytically. — Ash the contents of 
the can as on page 703. Wet the ash with concentrated nitric acid, add 
water, and boil Then make strongly alkaline with ammonia and filter. 
Unless the filtrate is colored blue, copper is absent. Transfer the filtrate 
to a bright tared platinum dish of loo-cc. capacity, neutralize with 
concentrated nitric acid, and add about 2 cc. in excess. Nearly fill the 
dish with water, and electrolyze with the apparatus described on page 
493, using a current of about 0.3 of an ampere. 

* Hilger u. Laband, Zeits. fiir Untersuch. Nahr. u. Genuss., II, p. 795; An. Rep. Mass. 
State Board of Health, 1899, p. 625. 



CANNED AND BOTTLED VEGETABLES, ETC. 705 

(2) Colorimelrically. — This method is especially applicable for small 
amounts of copper. The blue-colored ammoniacal solution of the ash, 
filtered as in (i), is transferred to a Nessler tube, and its color matched 
against the colors of a series of measured amounts of an ammoniacal 
standard solution of copper sulphate 

Determination of Nickel. — Boil the ash with water slightly acidified 
with hydrochloric acid, and without filtering, saturate with hydrogen 
sulphide, thus precipitating out any copper, tin, or lead. Filter and wash. 
Zinc and nickel, if present, are in the filtrate. Boil the filtrate to expel 
the hydrogen sulphide, and add sodium carbonate till slightly alkaline. 
Add acetic acid without fiUering till the precipitate produced by the 
alkaline carbonate is dissolved, and then add a considerable excess of 
acetic acid. The zinc is precipitated by passing hydrogen sulphide 
through the cold dilute solution, while the nickel is held in solution by 
the large excess of acetic acid. Filter, and wash with hydrogen sulphide 
water, to which a little ammonium acetate has been added. 

Make the filtrate alkaline with ammonia, precipitate the nickel with 
ammonium sulphide, filter, wash, ignite, and weigli as nickelous oxide. 

ANTISEPTICS IN CANNED FOODS. 

No class of food products stands so little in need of these added sub- 
stances to arrest fermentation as canned foods, if properly prepared; 
but, as a matter of fact, the use of antiseptics in this connection is on the 
increase. Prolonged heating for a sufficient length of time to perfectly 
sterilize the contents of a can is in some cases more or less detrimental 
to the appearance of the product, so that for this reason, as well as to save 
time in "processing," and furthermore to increase the keeping qualities 
of the goods after opening, many manufacturers resort to the use of arti- 
ficial chemical preservatives. So long as any well-founded prejudice 
against preservatives e.xists, their use in canned or bottled foods should 
be unequivocally condemned, unless the cans or packages are distinctly 
labeled with the nature of the preservative and the extent to which it 
is employed. 

As in other foods, discrimination as to locality is apparently used on 
the part of manufacturers in shipping canned goods containing added 
preservatives, so that, as a matter of fact, in states where it is well under- 
stood that a vigilant enforcement of the pure-food law prevails, we do 
not find as high a percentage of canned foods with preservatives as in 
other states. 



7o6 FOOD INSPECTION AND ANALYSIS. 

Preservatives commonly employed in canned goods are salicylic, 
benzoic, and sulphurous acids, though the other familiar antiseptic agents 
may be used. In such foods as canned corn, while the purpose of sul- 
phurous acid may be in part as a preservative, the primary object for 
its use is undoubtedly to bleach or whiten the product. 

The Bleaching 0} Corn by artificial means before canning is usually 
accomplished by boiling the corn with sulphite of soda, thus giving to 
the product an unnaturally white color. The practice seems to have been 
more in vogue ten years ago than at present, the popular taste now appar- 
ently preferring the natural rich yellow of fresh corn. 

Saccharin is claimed to possess antiseptic powers and is used in canned 
goods, but its primary purpose is as a sweetener. 

Beta-naphlhol is also said to be used as a preservative in canned 
goods, but has not been found by the author in any samples that have 
come to him for analysis. 

Detection of Preservatives. — Tests for salicylic or benzoic acid are 
most readily made in the residue from an ether extract of a portion of 
the acidified contents of the can or pacliage, while formaldehyde and 
sulphurous acid are tested for in the earlier portions of the distillate, 
obtained by distilling a mixture of the acidified contents in water. 

If it is desired to systematically test for the various preservatives 
in the same sample, a convenient method of procedure is as fol- 
lows: 

Thoroughly mix 50 grams of the pulped sample with water in a 250- 
cc. graduated flaslc, make distinctly acid with dilute phosphoric acid, and 
fill to the mark with water. Transfer to a distilling-flask, and subject to 
distillation in a glycerin- or paraffin-bath, whereby the temperature is 
raised near the end of the distillation considerably above 100° C. 

Remove the first 30 cc. of the distillate, and divide into three equal 
portions, which are to be tested for formaldehyde, sulphurous acid, and 
beta-naphthol by the usual tests for these preservatives. 

Continue the distillation till the residue in the flask is nearly dry, and 
transfer the remaining or larger portion of the distillate to a large separa- 
tor}- funnel. Acidify with dilute sulphuric or hydrochloric acid, and 
extract with ether or chloroform. 

Divide the ether or chloroform extract into three portions in as many 
evaporating-dishes, evaporate to dryness at low temperature, and make 
the appropriate tests on the thpee residues for salicylic acid, benzoic acid, 
and saccharin, as given in Chapters XVII and XVIII. 



CANNED AND BOTTLED VEGETABLES, ETC. 707 

The residue left in the flask is then washed out and incinerated, and 
the ash examined for boric acid. 

"soaked goods." 

It has become quite common, especially in the case of peas, beans, 
and corn, to utilize for canning purposes those that have grown old and 
dried, after soaking them for a long time. The presence of soaked peas 
in the market is generally more common in years when there is a scarcity 
in the pea crop. By the process of soaking, dried and matured field corn 
may be softened to such an extent as to be substituted for green or sweet 
corn in the canned product. These goods, frequently sold at a very low 
price, under some such tempting name as "Choice Early June Peas," are 
entirely devoid of that succulent property so highly prized in the fresh 
goods, and are altogether so inferior in quality that their sale may justly 
be considered as fraudulent, unless their character is specified. In some 
states the law provides that such a product, to be legally sold, shall 
have plainly marked on the label of the can the words "Soaked Goods" 
in letters of prescribed size. 

Detection. — Methods of detecting soaked goods are distinctly physi- 
cal rather than chemical. The appearance and taste of the goods furnish 
in most cases an unmistakable clue to their nature. Soaked goods are 
entirely lacking in juiciness, and in the flavors so characteristic of the 
various vegetables, when gathered and canned before becoming dry. 
The process of soaking is also said to develop the growth of the rudi- 
mentary stem of the embryo in the dried pea and bean. Peas and beans 
of the soaked variety are almost entirely lacking in the green color of 
the fresh vegetables, unless the color has been artificially supplied. 

In all cases it will be found that the solid grains or kernels of the 
peas, beans, and corn that have once been dried, though softened by 
the process of soaking, have much less water than the grains of the cor- 
responding vegetables that were gathered while still soft and succulent. 

KETCHUPS AND TABLE SAUCES. 

These preparations vary widely in their character and composition, 
and, in the absence of standards fixed by law for each particular mi.xture, 
almost any food product may be included in its make-up, vnthout laying it 
open to the charge of being adulterated. At the same time, in this class 
of condiments it is naturally expected that the ingredients used all have 
some food value, and in addition possess a certain degree of pungency 



7o8 



FOOD INSPECTION /tND AN/t LYSIS. 



or distinctive flavor. In other words, inert materials used simply as 

CHEMICAL COMPOSITION OF KETCHUP, PICKLES, AND RELISHES* 





Number 

of 
Analyses 


Refuse. 


Water. 


Protein. 


Fat. 


Total 
Carbo- 
hydrates 


Ash. 


Fuel 
Value 

per 
Pound. 


Tomato ketchup 

Horseradish 


2 
2 


27.0 
19.0 


82.8 
86.4 

58.0 
42-3 

64.7 
52-4 
92.9 

93-8 
77-1 


1-5 
1.4 

I.I 
.8 

1-7 

1-4 

•5 

I.I 

•4 


.2 

.2 

27.6 
20.2 

25-9 
21.0 

-3 
• 4 
.1 


12.3 

10-5 

II. 6 

8-S 

4-3 

3-5 

2-7 

4.0 
20.7 


3-2 

1-5 

1-7 
1.2 

3-4 

2-7 

3-6 

•7 
1-7 


265 
230 

1,400 
1,025 

1,205 

975 

70 

no 

395 


Olives, green: 

Edible portion 

As purchased 

Olives, ripe: 

Edible portion 

As purchased 

Cucumber pickles 

Mixed pickles 

Spiced pickles 



* U. S. Dept. of Agric, Office of Exp. Sta., Bui. 28, p. 70. 

"fillers" are, to say the least, out of place, even though they are not 
actually adulterants. 

Tomato Ketchup in its simplest form consists of boiled, fresh, ripe 
tomato pulp mixed with various spices, either with or without the addition 
of red peppers, sugar, and vinegar. The preparation, being usually 
strained through a sieve before bottling, is of smooth consistency and 
free from masses of pulp. 

The ketchup of the housewife is made from varj-ing recipes, all based 
on the above method of procedure; and while the commercial bottled 
ketchups should be made from materials quite as pure, it is often true, 
especially in the cheaper varieties, that the skins and refuse of tomato- 
canning factories form the basis of much of the ketchup in the market. 
Even with the use of these materials, when properly prepared, and before 
advanced fermentation has set in, with clean methods of handling, the 
product may not be unwholesome. It is, however, sometimes the prac- 
tice to allow the refuse and skins to accumulate through a whole tomato- 
canning season, storing them all in large vats, and working them up, after 
they have become badly fermented, for "fresh tomato ketchup." It is 
largely for this reason that antiseptics and coloring matters are so com- 
monly employed in ketchup. f Salicylic and benzoic acids are the anti- 
septics most commonly found. 

t The writer has in his possession a circular from an Indiana commission merchant, 
advertising for sale tomato pulp of some twelve different grades for ketchup. Among them 
are listed the following: "100 bbls. of old goods, made partly from whole stock and partly 
waste, boiled down nearly to ketchup thickness; has preservaline in it; fine goods but some 
of it is fermented; packed in good oak whiskey and wine barrels. Price $2.00 per bbl." 



CANNED AND BOTTLED l^EGETABLES, ETC. 709 

Coloring of Tomato Ketchup. — The practice of adding artificial 
dyestuffs to ketchup is very prevalent, but the brilliant magenta and 
crimson hues often imparted to the bottled ketchups on the market in 
no wise resemble the natural dull-red or brown color of the pure home- 
made article, in which the bright color of the fruit pulp is modified by 
the mixture of spices with which it is cooked. It is doubtless true that 
many manufacturers employ such inferior materials that unless some 
dyestuffs were added the result would be most unappetizing in appearance. 
Use of artificial coloring matters is not, however, universal. Out of 
ninety-five samples of tomato ketchup examined in 1901 in Connecticut, 
only fifteen were found uncolored.* 

Anilin dyes and cochineal are most commonly used for coloring. 

Wsilnut Ketchup. — This is made up in a somewhat similar manner 
to tomato ketchup, excepting that instead of tomatoes, soft young walnuts 
are crushed and used as a basis. 

Chili Sauce is made up of a pulped mixture of tomatoes, red peppers, 
onions, vinegar, and various spices, differing from ketchup in that it 
contains the seeds and is not strained. In consistency it is heavier than 
ketchup. It is colored and preserved in much the same manner as 
ketchup. 

Table Sauces are composed of a large variety of materials of a more 
or less pronounced flavor or pungency, combined in a liquid prepara- 
tion usually of a more thin or watery consistency than the ketchups. 
The materials employed include mushrooms, onions, garlic, ground ancho- 
vies, tamarinds, spices, coriander and cardamom seeds, walnuts, vinegar, 
molasses, and even assafoetida. These bottled preparations are very 
rarely colored except with caramel, but sometimes contain antiseptics, 
especially salicylic and benzoic acids. 

The Acidity of ketchups and table sauces furnishes a ready means 
of comparison between different varieties, and is conveniently expressed 
in terms of acetic acid. 

To determine the acidity, titrate i gram of the diluted sample with 
tenth-normal sodium hydroxide, using phenolphthalein as an indicator. 

"225 bbls. new goods, made from waste; has benzoate oj soda in it, Backed in uncharred 
whiskey and wine barrels at $3.00 per bbl. net cash." "300 bbls. old goods, partly whole 
stock, partly waste, has salicylic acid in it; nice goods, etc. Price $2.00 per bbl." "400 
bbls. new goods, Jersey style; solid and good red color, fine quality. Price $3.00 per bbl.'' 
JVith prices as low as the above quotations, it is difficult to see how a cheaper basis for ketchup 
stock than the above could be supplied. Even the pulp of pumpkin and of other inert vege- 
tables, alleged to be used as adulterants, would hardly be furnished so cheaply. 
* An. Rep. Conn. Exp. Sta., 1901. 



7IO FOOD INSPECTION /IND /IN A LYSIS. 

Each cubic centimeter of the alkali corresponds to 0.006 gram of acetic 
acid. 

Winton and Ogden * have found the acidity of tomato ketchups ex- 
amined by them to vary between the limits of 0.60 and 2.20 per cent, 
calculated as acetic acid, Chili sauce from 0.80 to 1.80 per cent, and 
various table sauces from 1.40 to 1.60 per cent. 

Examination of Table Sauces and Ketchups for Preservatives. — 
Extract a portion of the acid sample with ether or chloroform, which 
removes salicylic or benzoic acid or saccharin. If the sample is of thin 
or watery consistency, like most table sauces, the extraction can in most 
cases be readily effected in a separatory funnel, chloroform being in this 
case most convenient, since it sinks to the bottom. If ketchup or other 
thick syrupy substance is to be examined, it is almost impossible when 
shaking with ether or chloroform to avoid the formation of an annoying 
emulsion, which it is difficult to break up. For this reason the author 
prefers, in the case of ketchups and similar viscous fluids, to separate 
the extract by means of a centrifuge of the style shown in Fig. 11. A 
portion of the acid sample, say 75 cc, is shaken violently in a corked 
flask with 25 to 40 cc. of ether, and the mixture, usually in the form 
of an emulsion, is poured into two of the centrifuge tubes, so that they 
contain equal amounts and balance each other. They are then corked, 
placed in the shields of the centrifuge, and whirled from two to four 
minutes, or until the emulsion is broken up. At the end of this time 
it is usually found that the mixture is separated into three layers: first 
a watery layer at the bottom of the tube, then an almost solid layer of 
the viscous material above it, and finally the clear ether extract at the 
top. As a rule the separation is so complete that the tube may be 
inverted, and every drop of the clear ether layer may be decanted with- 
out filtration, so firmly does the solid middle layer hold in place in the 
tube. Indeed, a vigorous shake is usually necessary to dislodge it. 

If saccharin, as well as salicylic and benzoic acids are all to be looked 
for, the ether extract is divided into three portions, in as many evaporating- 
dishes, and the dried residue tested in the regular manner for the above 
substances. 

Examination of Ketchups for Colors. — Proceed as in the case of 
jellies and jams. 

*An. Rep. Conn. Exp. Sta., 1901, p. 137. 



C/1NNED AND BOTTLED yECETABLES, ETC. 711 

PICKLES. 

A large variety of vegetables and fruits are preserved in the form 
of pickles in vinegar, either with or without spices, and kept in wooden 
pails, stoneware pots, kegs, or sealed, wide-mouthed bottles. The con- 
tainers are not of necessity air-tight. The commoner vegetables are 
usually pickled without cooking, while with fruits, as in the case of 
peaches, pears, gooseberries, .etc., they are usually cooked, or at least 
heated. 

Cucumber Pickles are the most common, and are prepared by soaking 
the fresh cucumbers in strong salt brine. They are then dried on frames, 
and afterwards treated with boiling vinegar, to which spices may or may 
not be added. Other vegetables pickled in similar manner, either sepa- 
rately or in mixture with cucumbers to form "mixed pickles" or "gher- 
kins," are cauliflower, bean pods, white cabbage, young walnut-, and 
onions. 

Such soft vegetables as young podded beans and beets are not treated 
with brine, but, after soaking in water, are directly treated with vinegar. 
The vinegar used for the finest pickling is of the cider, wine, or malt 
variety. Cheaper varieties of pickles are put up in "white wine" or 
spirit vinegar. 

Mustard Pickles. — These differ from plain vinegar pickles in the 
character of the preserving medium, which in this case consists of a mix- 
ture of mustard and spices with the vinegar to form a thin paste. 

Piccalilli consists of a mixture in vinegar of various chopped vege- 
tables, such as cucumbers, cauliflower, green pickles, onions, green toma- 
toes, and various spices. 

Olives for pickling are picked before they have fully ripened, and the 
inherent bitter taste is removed by soaking in a solution of potash arid 
lime. This is replaced by cold water, and finally the olives are trans- 
ferred to the medium in which they are bottled, which consists of salt 
brine, either with or without flavoring. The flavoring materials employed 
consist of such substances as fennel, coriander, laurel leaves, and occa- 
sionally vinegar. 

Capers. — These are the flower buds of the shrub Capparis spinosa, 
which are pickled in vinegar. Nasturtium seeds, when similarly pickled, 
possess a flavor rnuch resembling capers, but their substitution for capers 
could readily be detected by their distinctive appearance, even if colored. 

Adulteration of Pickles. — Green pickles, such as cucumbers, are 



712 FOOD INSPECTION /tND ANALYSIS. 

not uncommonly colored artificially by copper salts, either through the 
addition of copper sulphate, as in the greening of peas, or by the use 
of copper vessels. This artificial greening is to be looked for also in such 
products as capers and olives. 

For methods of detection and estimation of copper, see page 704. 
Pickles may be greened by boiling with much less harmful substances 
than copper salts, such, for example, as grape leaves, spinach, or parsley. 

Free Sulphuric Acid has been found in a number of cases in the vine- 
gar of pickles bought on the Massachusetts market. A pronounced 
test for chloride with nitrate of silver should not be attributed to free 
hydrochloric acid, since it may be and probably is due to the salt from 
the brine in which the pickles have been treated. 

Alum is sometimes added to the salt solution to produce hardness 
and crispness in pickles. A number of samples of cucumber pickles 
have been found by the author to contain alum. For its detection, fuse 
the ash of the pickles, if free from copper, in a platinum dish with sodium 
carbonate, extract with boiling water, filter, and add ammonium chlo- 
ride. A flocculent precipitate shows alum. 

Horseradish. — This condiment is prepared by grating the root of 
the perennial herb Nasturtiutn armoracia, and preserving in vinegar. 
It is very pungent and aromatic when first prepared, but by exposure to 
light and air quickly loses strength. A common adulterant of bottled 
horseradish as sold on the market is the ordinary grated turnip, the pres- 
ence of which can be readily detected by means of the microscope. 

JAMS AND JELLIES. 

Jams or marmalades are prepared from the pulp of fruits, and jellies 
from the fruit juices. Both jams and jellies, to be considered of the highest 
degree of purity, should contain nothing but the fruit pulp or juice named 
on the label, mixed with pure cane sugar, and, in the case of jams, the 
further addition of spices and flavoring materials is permissible. 

For the manufacture of jam, the washed fruit, if of the kernel variety, 
is peeled, freed from cores, and sliced; if berries, they are simply stemmed; 
if stone fruits, they are peeled, freed from stones, and quartered. The 
material, properly prepared, is cooked with as much water as is necessary 
for boiling, and with the addition of an amount of sugar varying with 
different manufacturers. Some prefer to use equal parts of sugar and 
fruit, others one part sugar to two parts fruit. 

In the case of jelly, the fruit is cooked in a small amount of water 



CANNED AND BOTTLED yEGETABLES, ETC. 713 

till soft, transferred to a bag or press, and the juice allowed to flow out 
spontaneously, or is squeezed out under pressure, according to the grade 
of jelly desired, the clearest and finest varieties being made from the 
juice that flows out naturally. This juice is then evaporated down with 
the addition of sugar to a density of from 30° to 32° B^., which is of the 
proper consistency to form a perfect jelly product after cooling, and, while 
still hot, is poured into the tumblers in which it is to be kept. Here, as 
in the case of jams, the amount of sugar varies, some using pound for 
pound, and others only half as much sugar as fruit. Some manufacturers 
clarify their jellies by mixing whh the juice, while boiling, elutriated 
chalk, using a teaspoonful to each quart of juice. The impurities come 
to the surface with the chalk as a scum, and are skimmed off. This 
clarifying process is somewhat analogous to the defecation of sugar juices 
with lime, and is commonly carried out with apple jelly. 

The ' ' jellying " or gelatinizing of the final product is due to the presence 
in the fruit juice of pectin, or so-called vegetable jelly (C32Hj„0284H20); 
see page 217. 

The high content of added sugar in jelly, once thought to be essential 
for keeping it , is now no longer considered necessary, and much less sugar 
is at present added than formerly. The finest grade of apple jelly, for 
instance, is made without any added sugar whatever. 

In making the better grades of apple jelly, apple juice fresh from 
the press is run directly into the boiler or evaporator before any fermenta- 
tion has ensued, and gelatinized by concentration. If boiled cider is 
wanted instead of jelly, it is drawn off at an earlier stage than in the- case 
of apple jelly. 

Composition of Known-purity Jellies and Jams. — In the tables on 
pp. 714 and 715, due to Tolman, Munson, and Bigelow,* are given 
results reached on the examination of the pure finished products, as well 
as on pure fruit juices and pulp used in their manufacture. 

Adulteration of Jams and Jellies. — As a matter of fact, a small percent- 
age of these products sold in the United States are honest prototypes of 
the home-made jams and jellies, which consist exclusively of the fruit 
specified on the label, in mixture with pure cane sugar. If we accept as 
a standard the product of the housewife, fully 90% of the commercial 
brands of these preparations would be found wanting. So great is the 
demand for cheap sweets of this variety, that the market is flooded with 
them at eight and ten cents per half-pound jar, when in reality abso- 

* Jour. Am. Chein. Soc. (1901), pp. 349-351. 



714 



FOOD INSPECTION AND ANALYSIS. 



































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7i6 FOOD INSPECTION /tND AN /I LYSIS. 

lutely pure goods cannot be produced at much less than twice that 
amount. 

The cheap substitutes are made up largely of apple juice and com- 
mercial glucose, frequently containing no fruit whatever of the kind 
specified on the label. Sometimes an attempt is made to imitate the 
flavor by the addition of artificial fruit essences, but more often the same 
apple-glucose stock mixture of jelly, put out under a particular brand, 
serves to masquerade as damson, strawberry, raspberry, curre'nt, grape, 
etc., differing from each other only in color, but not as a rule in flavor. 
A variety of artificial colors are employed, mostly coal-tar dyes. To 
compensate for the lack of sweetness of the glucose, a minute quantity 
of one of the concentrated sweeteners, such as saccharin or dulcin, is some- 
times added. Besides artificial colors, antiseptic substances are commonly 
employed, especially salicylic and benzoic acids. 

All grades of apple stock are found in these preparations. A large 
source of supply is furnished by the parings and cores of canning estab- 
lishments, to say nothing of the refuse of these factories, such materials 
being boiled with water, and the extract, variously colored to imitate the 
different fruits, being evaporated with commercial glucose. 

Adulterated Jelly. — While it is easy to make an excellent apple jelly 
by simple evaporation of the pure apple juice, even without the addition 
of sugar, it is impossible, or at least difficult, to obtain the proper degree 
of stiffness with a mixture of apple stock and commercial glucose. It is 
customary, in the manufacture of cheap jellies, therefore, to employ 
what is technically termed a " coagulator," consisting commonly of sul- 
phuric acid, to which sometimes alum is added. Citric or tartaric acid 
is also used for this purpose, as well as to increase the acidity. About 
1% of the acid will cause the mass to gelatinize satisfactorily. 

The lowest grade of apple jelly is made from the exhausted pomace, 
left as a residue after pressing out the juice for cider. Such stock is com- 
monly mixed with water, and boiled down with glucose. Having been ex- 
hausted of its malic acid, pectose, and other soluble constituents, it lacks 
much of the flavor inherent in pure apple jelly. Various foreign gelat- 
inizing agents are found in cheap jellies and preserves, such as starch, 
gelatin, and agar-agar. In the low-priced goods, starch paste is a fre- 
quent adulterant. It should be remembered that starch exists in unripe 
apples, but hardly at all in the mature fruit, so that while mere traces of 
starch in jelly may be due to the use of green apples, its presence in large 
amounts is undoubted evidence of the admixture of starch paste. 



C/INNED /1ND BOTTLED yEGETABLES, ETC. 7^7 

Adulterated Jams. — Most of the cheap jams and bottled preserves 
sold on the market, though reinforced with apple stock, do in reality 
contain masses of fruit and berries of the kind stipulated on the label, as 
even a casual megascopic examination will show. That such low-priced 
preparations really contain genuine fruit pulp is not to be wondered at, 
when it is considered that much of the virtue of this fruit has sometimes 
been previously extracted by boiling, to produce fruit juices for higher- 
priced goods. Or, as in the case of jams containing strawberries, rasp- 
berries, and other small fruits with seeds, the juice is apt to have been 
previously expressed for pure jellies, while the residues are afterwards 
worked up with apple stock for low-priced jams. Hence the presence of 
pure fruit stock, or genuine berry seeds and pulp in jams, is in itself no 
criterion of purity, and, furthermore, it is unnecessary' to use hay seed and 
other alleged foreign seeds as aduherants of cheap jam. 

Compound Goods. — Many states have a law legalizing the sale of 
"compound" goods, providing they are distinctly so labeled. In other 
states, as, for instance, Massachusetts, the label must plainly state the 
name and percentage of the ingredients. In either case the analyst must 
discriminate, in classifying the inferior or low-grade preparations, between 
those that are labeled in accordance with the law, and those that are not. 
Only those not properly labeled can in such cases be classed as adulter- 
ated within the meaning of the law. Where such a law prevails, probably 
no class of food-products is so extensively affected by it as the low-grade 
jams, preserves, and jellies. 

The restrictions as to labeling do not in all cases eliminate the element 
of deception. It is hardly justifiable, for example, to boldly label an 
alleged "currant jelly" which contains no currant, in the following man- 
ner: 

Fruit juice 25% 

Cane sugar 14% 

Com syrup 61% 

100% 

The use of the term "fruit juice" surely implies to the unsuspecting 
purchaser that so much pure currant juice has entered into the jelly, else- 
where labeled in large letters "Currant," whereas all the juice is apple, 
and no currant juice has been used. 

The following label is a type of those which discriminate between pure 
fruit and apple juice: 



7i8 



FOOD INSPECTION AND ANALYSIS. 



Fruit 30% 

Com syrup 35% 

Granulated sugar 15% 

Apple juice 20% 

100% 

Composition of Cheaper Grades. — Out of 66 samples of jellies, jams, 
and preserves analyzed by Winton, Langley, and Ogden in Connecticut, 
the samples being purchased in that state,* 17 samples contained starch 
paste, 35 were artificially colored with coal-tar dyes, and 19 contained 
salicylic or benzoic acid. 

The following table has been compiled, showing the sugar content of 
some of the typical commercial jellies and jams analyzed in the laboratory 
of the Massachusetts State Board of Heahh. Nearly all of these were 
artificially colored, and found to contain little if any fruit, other than apple. 



Direct 


Invert Polarization. 










Per Cent 








Sucrose. 




At 20° C. 


At 87° C. 




+64.0 


+ 28.0 


+ 36.0 


26.8 


+ 29.2 


+ 20.0 


+ 36.4 


6.9 


+ 41-6 


+ 33-9 


+ 40-8 


S-7 


+ 62.0 


+ 34-4 


+ 46.0 


20.6 


+ 119. 8 


+ 108.8 


+ IIO.O 


8.2 


+ 114. 


+ 107.6 


+ IIO.O 


4.9 


+ 112.0 


+ 92.0 


+ 93-6 


14.9 


+ 107.0 


+ 94-4 


+ i;8.i 


9-3 


+ 95-2 


+ 90-9 


+ 83.6 


3-2 


+ 99.0 


+ 93-5 


+ 85.6 


4-1 


+ 49-6 


+ 43-6 


+ 42.0 


4.5 


+ 123.6 


+ 119-2 


+ 102.5 


2.6 


+ 77.6 


+ 6';. I 


+ 46.9 


9-3 


+ 66.0 


+ 29-S 


+ 37-2 


27.2 


+ 119. 8 


+ 108.8 


+ IIO.O 


8.2 


+ 41-8 


+ 21.3 


+ 32.6 


15-4 


+ 83.6 

* 


+ 72.0 


+ 78.8 


8.7 



Per Cent 
Commer- 
cial 
Glucose. 



JELLY. 

Apple 

Currant A 

B 

Grape 

Peach 

Pineapple 

Raspberry 

JAM. 

Damson A 

B 

Apricot 

Quince 

Raspberry A 

B 

C 

Pineapple 

Strawberry A 

B 



22.1 
22.3 
25.0 
2 
4 
4 
4 



28, 
67 
67 
57 



35-6 

51-2 
52-4 
25-7 
62.8 
28.7 
22.8 
67.4 
20.0 
48.3 



Methods of Analysis. — As in the case of canned goods, but little 
information is to be derived as to adulteration of jams, jellies, and pre- 
serves by the ordinary determinations of moisture, ash, and nitrogen, and 
these are rarely made by the public analyst. 

Of considerable importance in this regard, however, are the sugar de- 
terminations, made with a view to ascertaining the varieties of sugar 



* An. Rep. Conn. E.xp. Sta., 1901, p. 130. 



C/tNNED /1ND BOTTLED VEGETABLES, ETC. 719 

employed, as well as their approximate proportion in the products exam- 
ined. 

Total Solids. — Ten grams of the jam, which has been evenly pulped 
in a mortar, or 5 grams of the jelly, are weighed into a tared platinum 
dish, taking care to spread the sample as thinly as possible over the bot- 
tom of the dish, and dried to nearly a constant weight at 100°. Results 
yielded by this method, while sufficiently close for ordinary work, are not 
exact, due to the slight dehydration of the sugars. If extreme accuracy 
is required, dry in vacuo at 75° C, or in a McGill oven, page 481. 

Soluble and Insoluble Solids. — A weighed amount of the evenly pulped 
sample, say 25 grams, is vigorously shaken in a 500-cc. graduated flask 
with water, preferably with the aid of a mechanical shaker, and, after 
filling to the mark, is again shaken. The residue is allowed to settle, and 
the supernatant liquid is decanted through a filter, and an aliquot portion 
of the filtrate, say 50 cc, is measured into a tared dish and evaporated to 
dryness, dried at 100° to a constant weight, and weighed for soluble solids. 
Insoluble solids are calculated by difference. 

Ash. — The residue from the total solids is burnt at dull redness to an 
ash, cooled in a desiccator, and weighed. 

Nitrogen is determined by the Gunning method, page 61, in from 
5 to 10 grams of the uniformly mi.xed sample. 

Determination of Sugars. — In products of the highest grade, 

wherein only cane sugar is employed, a large portion of the cane sugar 
is inverted in the process of boiling the jam or jelly, so that when the 
analyst examines it, he finds, as a rule, only a small amount of sucrose, 
and considerable invert sugar. It is possible, however, to calculate the 
amount of cane sugar originally employed, if such information is desir- 
able. It is further of interest to calculate, at least approximately, the 
percentage of commercial glucose, when present, especially in cases where 
the package contains a formula setting forth the amount of the various 
ingredients used. In such cases the analyst is naturally called upon to 
verify the formula, since a wide variation in percentage composition from 
the statement on the label would constitute an offense under some state 
laws. 

Polarization.— Use half the normal weight of the preserve or jelly for 
the Schmidt and Haensch instrument, viz., 13.024 grams in 100 cc. If 
fresh fruit or fruit juice is to be examined, use the full normal weight, 
26.048 grams. Clarify, before making up to the mark, with subacetate of 
lead and alumina cream (using 2 to 3 cc. of each clarifier), filter, and 



720 FOOD INSPECTION AND /IN A LYSIS. 

obtain the direct reading; then invert in the usual manner, and obtain 
the invert readings at 20° C, and in the water-jacketed tube at 87° C, 
proceeding in detail as directed under honey, p. 515. 

Calculation of Sugars. — Sucrose is determined by using Clerget's 
formula : 

(a— 6)100 



t 
144- 



(I) 



2 



This represents the sucrose actually present as such in the preserve 
or jelly, and not the amount originally used. If the latter is desired, it 
may be calculated from the formula, 

loob 

•5'= T (2) 

44-Y 

where S' is the per cent of cane sugar originally used, and h is the invert 
reading at t° of the normal solution. 

If, after inversion, the correct reading at 20° is found to be 10 or more 
to the left of the zero, it can be safely inferred that no appreciable amount 
of commercial glucose is present, and it is unnecessary to make a third 
reading at 87°, unless to confirm the fact. In such a case, with cane sugar 
alone present, the reading at 87° will not, of course, vary much from o. 

Invert Sugar. — In the absence of commercial glucose, the invert sugar 
is calculated as follows : 

(Sucrose— direct reading)io^. 3 
Invert sugar = — , ... (3) 

44-7 

or it mav be determined directly from the copper reducing power. 

Any decided reading above zero at 87° is due to the presence of com- 
mercial glucose, and when the latter is present, it is impossible to deter- 
mine the invert sugar from the copper reduction or by formula No. 3. 
The following formula is proposed for calculating approximately the 
invert sugar from the polarization, in the presence of commercial glucose. 
While theoretically correct, the method is subject to practical limitations, 
which admit of only roughly approximate results in such mixtures as 
jelly or jam. It is perfectly accurate only in mixtures of sucrose, glu- 
cose, and invert sugar. 



CANNED AND BOTTLED VEGETABLES, ETC. 721 

/Reading due to glucose and\ /Invert reading\ 

I inverted sucrose at /° / ~ \ at /° / 
Invert sugar = -^ j^ 105.3 (4) 

44-- 

These formulas, (3) and (4), serve at best to indicate the approximate 
amount of invert sugar present in the sample, resulting from the inver- 
sion of a portion of the original sucrose in the natural process of manu- 
facture of the jam or jelly, and not the total invert sugar resulting from 
the inversion by the analyst of all the sucrose. 

The factor 105.3 ^^ used, since, in the natural process of inversion, 100 
parts of sucrose become 105.3 parls of invert sugar. 

Example. — The invert sugar in the sample of apple jelly first on the 
list in the table on page 718 is calculated as follows: 

Invert reading at f (20°) = 28.0. 

Reading due to glucose at 2o° = .22iX 175 = 38.68. 

" " " inverted sucrose at 20° = .268X —34= —9. 11. 

(38.68 -g.ii)- 28 
Invert sugar = ioS-3 

= 4.86%. 

Reducing Sugar by Copper Reduction.* — Five grams of the pre- 
serve or jelly (or 25 grams of the fresh fruit or fruit juice) are transferred 
to a 100 cc. graduated flask, clarified by the addition of 2 or 3 cc. each 
of subacetate of lead and alumina cream, made up to the mark, shaken, 
and filtered. An aliquot part of the filtrate is then measured into another 
100 cc. flask, and treated with enough of a saturated solution of sodium 
sulphate to precipitate the lead, after which it is made up to the mark and 
filtered. The amount of sugar solution measured off into the second flask 
is such that, when finafly made up to 100 cc. as described, approximately 
J of 1% of reducing sugar is present, as roughly estimated by the total 
solids and polarizations. The reducing sugar is then determined in 
the filtrate as dextrose by Defren's method, page 489, or if Allihn's 
method is used (p. 493) the amount of reducing sugar present should 
approximate 1%. 

Commercial Glucose. — Wliile it is impossible to determine the exact 
percentage of this substance in preserves and jellies, by reason of the 
varying composition of its component parts, it is quite feasible to approx- 
imate very closely to the amount present. Indeed, this approximate 
* U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 78. 



722 FOOD INSPECTION AND ANALYSIS. 

method of calculation, wherein glucose is treated as a chemical entity, 
has been found in practice to be much more close to the actual truth 
than results gained by methods wherein the copper reducing power enters 
as a factor, or methods for determining separately dextrin, maltose, and 
dextrose. Calculate the commercial glucose in jellies and jams exactly 
as in the case of honey, p. 514. 

Dextrin.* — If alcohol be added to a somewhat thick solution of the 
fruit product, a white turbidity is at once apparent, followed by the forma- 
tion of a thick gummy precipitate, if dextrin is present. In the absence 
of dextrin there is no turbidity, but a hght flocculent precipitate. 

To determine the dextrin, dissolve f 10 grams of the sample in a loo-cc. 
flask; add 20 mg. of potassium fluoride, and then about one-quarter 
of a cake of compressed yeast. Allow the fermentation to proceed below 
25° C. for two or three hours to prevent excessive foaming, and then 
place in an incubator at a temperature of from 27° to 30° C. for five days. 
At the end of that time clarify with lead subacetate and alumina cream; 
make up to 100 cc. and polarize in a 200-mm. tube. A pure fruit jelly 
will show a rotation of not more than a few tenths of a degree either to 
the right or to the left. If a Schmidt and Haensch polariscope be used, 
and a 10*^ solution be polarized in a 200-mm. tube, the number of degrees 
read on the sugar scale of the instrument, multiphed by 0.8755, will give 
the percentage of dextrin, or the following formula may be used: 

Percentage of dextrin = 



igSxXXPK' 

in which 

C = degrees of circular rotation, 

V = volume in cubic centimeters of solution polarized, 

L = length of tube in centimeters, 

IF = weight of sample in solution in grams. 

Determination of Tartaric Acid. J — To 100 cc. of the fruit juice 
add 2 cc. of glacial acetic acid, 2 or 3 drops of a 20% potassium 
acetate solution, and 15 grams of pure finely powdered potassium 
chloride; dissolve this by shaking, and then add 20 cc. of 96% 
alcohol. Then stir vigorously for one minute, rubbing the walls of the 

* Bur. of Chem., Bui. 65, p. 78. 

t Bigelow and McElroy, Jour. Am. Chem. Soc, 1893, 15, 668. 

X Halenke & Moslinger, Zeit. anal. Chem., 1S95, 34, 283; Bur. of Chem., Bui. 65, p. 80. 



CANNED AND BOTTLED VEGETABLES, ETC. 723 

beaker with the glass stirring-rod to start the crystallization of the potas- 
sium bitartrate. Allow to stand fifteen hours at room temperature. 
Filter, and wash the precipitate into a Gooch crucible with a thin asbestos 
felt, using the vacuum pump. Wash with a mixture of 15 grams 
of potassium chloride, 20 cc. of alcohol, and 100 cc. of water. The 
beaker is rinsed three times with a few cubic centimeters of this solution. 
The precipitate is also washed with a few cubic centimeters, but so that 
not more than 20 cc. in all of the wash solution is used. The precipitate 
and asbestos filter are washed back into the beaker, and heated to boiling. 
While still hot, the solution is titrated with decinormal alkali, using 
phenolphthalein as indicator. To the amount of alkali used must be 
added 15 cc. for the potassium bitartrate remaining dissolved in the 
solution. I cc. of decinormal alkali is equivalent to 0.0150 grams of 
tartaric acid. 

Determination of Citric Acid.* — Fifty cubic centimeters of the fruit 
solution is evaporated on the water-bath to a syrupy condition. To 
the residue add, very slowly at first, stirring constantly, 95% alcohol 
until no further precipitate is formed; 70 to 80 cc. are generally enough. 
Filter, and wash the residue with 95% alcohol. Evaporate the filtrate 
to eliminate the alcohol, take up the residue with a little water, and 
transfer to a graduated cylinder, making up to 10 cc. To 5 cc. of this 
solution, add half a cubic centimeter of glacial acetic acid, and to this 
add, drop by drop, a saturated solution of lead aCetate. The presence 
of citric acid is shown by the appearance of a precipitate, which possesses 
the property of disappearing on being heated, and reappearing on cooling. 
In order to separate the citric acid from other acids, heat to boiling, filter, 
and wash with boiling water; then allow to cool, and the precipitate of 
lead citrate will re-form. This lead precipitate may be filtered off, 
washed with weak alcohol, dried, weighed, and the citric acid calculated. 
It is necessary that there shall be no tartaric acid present. If the tartaric 
acid has been estimated, any error on this account may be avoided by 
adding enough decinormal potash to neutralize the tartaric acid before 
the alcohol is added. 

Detection of Coloring Matter. — Boil white woolen cloth or worsted 
in a solution of the jelly or jam, acidified with hydrochloric acid, or with 
acid sulphate of potassium, according to Arata's method, and test for 
the color on the dyed fabric by methods given in detail in Chapter XVI. 

* Moslinger, Zeit. Unter. Nahr. u. Genuss., 1899, 2, p. 93; U. S. Dept. of Agric, Bur. 
of Chem., Bui. 65, p. 80. 



724 FOOD INSPECTION AND ANALYSIS. 

Detection of Preservatives and Concentrated Sweeteners. — Extract an 
acid aqueous solution of the fruit product with ether or chloroform in 
a scparatory funnel, and test for benzoic and salicylic acids and for sac- 
charin in the ether extract. If dulcin is suspected, extract with acetic 
ether. 

Detection of Starch.* — Heat an aqueous solution of the preserve 
or jelly nearly to the boiling point, and decolorize by the addition of several 
cubic centimeters of dilute sulphuric acid and afterwards permanganate 
of potassium. This treatment does not affect the starch, which is tested 
for with iodine in the ordinary manner in the solution after cooling. In 
the clear filtrate from a boiled apple pulp solution, free from added starch, 
little or no darkening should occur on the addition of the iodine reagent. 
If, however, the reagent is added to the residue of the previously boiled 
pulp, the presence of starch inherent in the apple is usually recognized 
by the blue color produced thereon. 

The presence of any considerable added starch paste in a fruit prepa- 
ration is thus readily indicated by an intense blue color obtained by adding 
the iodine reagent to the filtrate (free from fruit pulp). 

Detection of Gelatin. — Robin's Metliod.'f — Add to a thick aqueous 
solution of the preserve or jelly sufficient strong alcohol to precipitate 
the gelatin. Decant the supernatant liquid after settling, set aside part 
of the precipitate, and dissolve the remainder in water. Divide the latter 
solution in two parts, to one of which add, drop by drop, a fresh solution 
of tannin, which precipitates gelatin if present. To the remainder add 
picric acid solution, which in presence of gelatin forms a yellow precip- 
itate. The portion of the yellow precipitate set aside is transferred to 
a test tube, and heated over the flame with a little quicklime. If gelatin 
is present, ammonia will be given oflF, apparent by the odor, and by fumes 
of ammonium chloride when a drop .of hydrochloric acid on a glass rod 
is held at the mouth of the bottle. 

Lepnann and Beatn's Method-X — Boil the sample with water, filter, 
and boil the filtrate with an excess of potassium bichromate. Cool, and 
add a few drops of sulphuric acid. A flocculent precipitate indicates gelatin. 

Detection of Agar Agar. §— The jelly is heated with 5% sulphuric 
acid, a little potassium permanganate is added, and, after settling, the 

* U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 81. 
t Girard et Dupre, Analyse des Matieres Alimentaires, p. 578. 
X Select Methods of Food Analysis, p. 324. 

§ Marpmann, Zeit. f. angew. Mikrosk, 1896, p. 260; U. S. Dept. of Agric, Bur. of 
Chem., Bui. 65, p. 81. 



C/iNNED AND BOTTLED VEGETABLES, ETC. 7^5 

sediment is examined by the microscope for diatoms, which will be found 
in large numbers if agar agar has been used. 

Detection of Apple Pulp. — A distinct clue to the presence of apple 
pulp in fruit preparations is often furnished by the characteristic apple 
odor given o£f when a small amount of the sample is heated to boiling 
with water in a test tube. Under such conditions, the apple odor is quite 
apparent, as distinguished from that of other fruits, especially if the 
apple is the chief fruit present, or predominates in the mixture. 

Apple pulp in fruit preserves, free from added starch, may usually 
be recognized by a microscopical examination, using iodine reagent. 
The cell contents of the pulp will show the characteristic blue color, 
undoubtedly due to portions of unconverted starch still remaining in 
them. 

Detection of Fruit Tissues under the Microscope. — It is a matter 
of some difficulty, by means of a microscopical examination, to identify 
with certainty the various fruits and vegetables that might be used in 
a jam or jelly as adulterants. The structural features of the common 
fruits, while possessing distinctive points of difference when examined 
separately and in the raw products, are so changed or broken down by 
the process of cooking, as to be with difficulty recognizable. The soft 
parenchyma which forms the main portion of the tissue of the fruit pulp 
is, as a rule, more or less disintegrated. 

In the case of some of the smaller fruits, as the currant and raspberry, 
the cuticles resist the cooking process to such an extent as to show charac- 
teristic fragments, often recognizable in preserves and jellies under the 
microscope. 

FRUIT JUICES. 

Sweet cider, orange juice, lime juice, grape juice, raspberry shrub, 
and the juices of various other fruits and berries, may be so prepared 
and sterilized as to keep without fermentation when bottled, and are 
so put up in considerable variety, either with or without the addition of 
sugar. 

Such preparations, if of the highest purity, should consist of the 
undiluted juices of these fruits, separated by pressure and carefully ster- 
ilized and bottled. They should contain no other fruit juice than that 
specified on their labels, and should be free from alcohol, added antisep- 
tics, or coloring matter, unless the label specifies the presence of the added 
foreign materials. The addition of pure cane sugar to such prepara- 



726 



FOOD INSPECTION AND ANALYSIS. 



tions as grape juice is allowable, as well as charging with carbon dio.xide 
to form so-called carbonated drinks. 

The following analyses of pure fruit juices are taken from tables 
prepared by Winton, Ogden, and Mitchell, showing results on samples 
purchased in the Connecticut market, as well as on some samples made 
in the laboratory.* 



COMMERCIAL FRUIT 
JUICES. 

Blackberry 

Cherry 

Black currant 

Red currant 

Grape 

Lime fruit 

Orange 

Pineapple 

Plum 

Quince 

Black raspberry 

Strawberry 

MADE IN LABORA- 
TORY. 

Peach 

Red raspberry 

Blackberry 

Huckleberrj' 

Pineapple 



Solids 



5-32 
14-33 
10.00 

7-5S 
15-29 

7.78 
12.72 

8.07 
10.81 
10.41 

8.47 

5-69 



12.70 

9.41 

8.94 

11.40 

13-90 



Acids 
Other 
than 
CO^as 
Citric. 



0.65 
o.So 
2.41 
2.og 
0.91 
6.50 

2-44 
0.81 
1. 00 
0.99 
1.36 
0.99 



0.95 
1. 19 
1.22 

°-5i 
0.68 



Cane 
Sugar. 



0.0 
0.0 
0.0 
0.0 
0.0 

1-5 
0.0 
0.0 



5-4 
0.8 
0.0 
0.6 

7-4 



Invert 
Sugar. 



4.6 

6-5 
9-2 

7-2 

21.7 

0.0 
7-1 
5-1 
°-3 
16.7 

7-8 
5-' 



2. 1 
8.6 
8.7 
16.7 
9.1 



Polarization. 



Direct. 



-1-3 
-1-9 
-2.7 
-2.1 

-6-5 
0.0 
-2.1 
0.0 
-0.1 
-S-o 
-2.3 
-1-5 



4.5 
-1.6 
-2.4 
-4.0 

4-7 



After 
Inver- 
sion. 



-1-3 
-1-9 
-2.7 
-2.1 

-6.5 
0.0 
-2.1 
-2.0 
-0.1 
-5-° 
-2-3 
-1-5 



-2.2 
-2.8 
-2.4 
-4.8 
-4.8 



Temper- 
ature 
C. 



29.0 
26.0 
26.0 
27.0 
25.0 

26.0 
26.0 
26.0 

25-0 
26.0 
26.0 



28.0 
26.0 
30.0 
30.0 
28.0 



Invert 
Reading 
at SI)" C. 



0.0 
0.0 



- i.o 
-0.8 



Antiseptics found most commonly in these preparations are boric, 
salicylic, benzoic, and sulphurous acids. Beta-naphthol should also be 
looked for. For methods of separation and examination see Chapter XVII. 

Unf ermented Grape Juice has the following average composition : f 





Austria, 
Per Cent. 


California, 
Per Cent. 


Solid contents by spindle 
(Balling) 


21.62 
None 

.78 

.01 

19.62 

.61 

•°3 
-37 
.02 


20.60 
None 
•53 
-°3 
19-15 
-59 
.07 
.19 
.04 




Total acid (as tartaric) 


Grape sugar 






Ash 


Phosphoric acid 





* An. Rep. Conn. Exp. Sta., 1899, p. 136. 



t California Exp. Sta., Bui. 130. 



i 



CANNED AND BOTTLED yECETABLES, ETC. 



727 



Grape juice is prepared by sterilizing at a temperature of 80° the 
juice expressed from the crushed grapes, filtering by means of a press 
or otherwise, and sealing in carefully sterilized bottles. After bottling, 
a final sterilization is conducted at a temperature 5° below the first. 
Bottled grape juices are rarely carbonated. 

Bottled Sweet Cider.— The composition of pure, freshly expressed 
apple juice is shown by the following table of analyses by Browne:* 























Left- 














Total 






Unde- 


handed 










Su- 


Total 


Sugar 


Free 




ter- 


Rotation 




Gravity. 


Solids. 


Suigar. 


crose. 


Sugar. 


after 
Inver- 
sion. 


Malic 
Acid. 


Ash. 


mined 

(Pectin, 

etc.). 


Degrees 

Ventzke 

400 mm. 

Tube. 


Red astrachan 


1-0532 


12.78 


6.87 


3-63 


10.50 


10.69 


1. 14 


0-37 


0.77 


23.72 


Earlv harvest 


1-0552 


13-29 


7-49 


3-97 


11.46 


11.67 


0.90 


0.28 


0.65 


24-32 


Yellow transparent. 


1.0502 


II. 71 


8.03 


2.10 


10.14 


10.24 


0.86 


0.27 


0.44 




Sweet bough 

Baldwin, green. .. . 


I.04Q8 
r.0488 


11.87 
11.36 


7.61 
6.q6 


3.08 
1.63 


10.69 
8.59 


10.8s 
8.68 








39-40 
36.16 


1.24 


0.31 


I .22 


' ' ripe 


1.0736 


16.82 


7-97 


7 -05 


15.02 


15-39 


0.67 


0.26 


0.87 




Ben Davis 


1-0539 


12.77 


7. II 


3-85 


10.96 


II. 16 


0.46 


0.28 


1.07 


49.00 



Bottled sweet cider, properly sterilized, should not differ materially 
from the fresh juice, and should contain no alcohol. 

Salicylic acid is the antiseptic most commonly found in sweet bottled 
ciders examined by the writer. 

Lime or Lemon Juice. — This, according to the U. S. Pharmacopoeia, 
should consist of the freshly expressed juice of the ripe fruit of Citrus 
limonum (Risso), natural order of Rutaceee. Our supply of both lemons 
and limes comes chiefly from the West Indies and the Mediterranean. 
Both varieties of the genus Citrus are used indiscriminately for furnish- 
ing commercial lime juice, though strictly speaking, only that of the 
lemon is recognized in the Pharmacopoeia. The juice is sharply acid, 
and is largely composed of citric acid (about 7%), gum, sugar (3 to 
4 per cent), and inorganic salts from 2 to 2J per cent. It also usually 
contains a little lemon oil from the rind. According to the pharmacopoeia, 
lemon juice [Lemonis succus) should conform to the following require- 
ments: 

"Specific gravity: not less than 1.030 at 15° C. 

"It has an acid reaction upon litmus paper, due to the presence of 
about 7% of citric acid. 



* Penn. Dept. Agric, Bui. 58, p. 29. 



728 FOOD INSPECTION yIND ANALYSIS. 

"On evaporating loo grams of the juice to dryness, and igniting the 
residue, not more than 0.5 gram of ash should remain." 

Of thirty samples of commercial lime juice examined in the Massa- 
chusetts State Board of Health laboratory, representing fifteen brands,, 
all were deficient in citric acid, containing from 1.92 to 4.15 per cent, 
thus showing that these preparations are frequently watered. Fifteen 
were found to contain salicylic acid, seven had sulphurous acid, while 
two contained both these preservatives. Several were found colored 
with coal-tar dyes. 

One sample examined by the author, purporting to be a "pure West 
Indian Lime Juice, triple refined," proved to be a mixture of hydrochloric 
and salicylic acids, colored with a coal-tar dye, and contained no lime 
juice whatever. 

Acidity of lime juice is obtained by titrating 6.8 cc. of the sample 
against tenth-normal sodium hydroxide with phenolphthalein. The num- 
ber of cubic centimeters of the standard alkali required, divided by 10, 
gives the per cent of citric acid present. 

FRUIT SYRUPS. 

Two classes of these preparations are on the market, one for use in 
soda-fountains, and one for "family trade," intended as a basis for 
sweetened drinks to be diluted with water and sugar. Some are made 
exclusively from pure fruit pulp and sugar, sterilized by heating and put 
up in tightly sealed bottles, while others of the cheaper variety are more 
apt to be entirely artificial both in color and in flavor, deriving the latter 
principally from the wide variety of artificial fruit essences now available. 
Commercial glucose is a frequent ingredient. The same classes of coal- 
tar dyes and antiseptics are found in these preparations as in the other 
fruit products. Fruit syrups are frequently found to contain such 
materials as gum arable and quillaia, or soapbark, used both for a 
thickener, and to give a "bead" or froth when used in soda water, and 
in connection with carbonated drinks. 

For purposes of comparison with such fruit-pulp preparations as 
may come to the analyst for examination, he is referred to the analysis 
of fruits found on page 215. 

FLAVORING EXTRACTS. 

By far the most extensively used flavoring extracts are those of vanilla 
and lemon, and in comparison with these the sale of all other varieties 



CANNED AND BOTTLED yEGETABLES, ETC. 7*9 

is comparatively insignificant. These two favorite essences are employed 
in nearly every household, and form a necessary adjunct to almost all 
forms of desserts, cakes, and confections, as well as to a wide variety 
of commercial preparations. 

Vanilla Extract. 

The Vanilla Bean is the source of pure vanilla extract, besides being 
used in chopped form directly as a flavoring agent. It is the fruit of 
the plant of the Vanilla planijolia, or flat-leaved vanilla. This climbing, 
perennial plant belongs to the orchid family, and is indigenous to Central 
and South America and the West. Indies, but by far the highest prized 
beans are cultivated in Mexico. While different varieties differ in some 
details, the best cured beans of commerce, as a rule, are from 20 to 25 cm. 
in length and from 4 to 8 mm. thick, drawn out at their ends and curved 
at the base. They are rich dark brown in color, of a soapy or waxy 
nature to the touch, deeply rifted lengthwise, and covered with fine frost- 
like crystals of vanillin. Wlien cut crosswise, the bean exudes a thick, 
odorless juice, containing calcium oxalate crystals. 

The cross-section of the bean is ellipsoidal in shape. The thick 
brown walls inclose a triangular cavity, in which are the lobed placentas. 
Between these are papillae, secreting a finely granular,, yellow, balsam- 
like substance that contributes much to the flavor of the extract, and 
helps to give the cut bean its delicious odor. 

When first gathered, the beans are yellowish green, fleshy, and with- 
out odor, developing their peculiar consistency, color, and smell by the 
process of fermentation or "sweating," which differs in various countries. 
According to the best methods the beans are sun-dried for nearly a month, 
being alternately pressed lightly between the folds of blankets, and 
exposed to the air. After the curing, they are packed in bundles. 

Quicker methods of curing consist of the use of artificial heat and 
calcium chloride for drying, but the products so prepared are considered 
inferior in quality. 

The Mexican vanilla beans are of the choicest grade, and command 
a high price, varying from ten to fifteen dollars per pound. The Bourbon 
beans, grown in the Isle of Reunion, are next in grade. These beans 
are shorter than the Mexican and much less expensive. They resemble 
the Tonka bean in odor. Beans from Seychelles and Mauritius are 
even shorter than the Bourbon beans, and are largely exported to England. 
The cheapest varieties are those from South America and Tahiti, which 



73© FOOD INSPECTION AND ANALYSIS. 

do not bring half the price of the Mexican beans, and the so-called 
"vanillons," or beans of the wild or uncultivated vanilla plants. These 
latter are used more in sachet powders and perfumes, possessing an 
odor not unlike heliotrope. 

Composition of the Vanilla Bean. — The following are results of the 
analyses of two varieties of vanilla beans, according to Konig: 

A. B. 

Water 25.85 30.94 

Nitrogen bodies 4.87 2.56 

Fat and wax 6.74 4.68 

Reducing sugar 7.07 9.12 

Non-nitrogen substances 30.50 32.90 

Cellulose 19.60 15-27 

Ash 4.73 4.53 

Vanillin. — Under "non-nitrogen substances" in the above table are 
included vanillin, the principle to which vanilla owes its peculiar odor. 
This body (CsHgOs) is the methyl ether of protocatechuic aldehyde, and 
is found on the surface of the bean in iine cr}'stalline needles. It has a 
sharp but pleasant flavor, is soluble with difficulty in cold water, but 
readily soluble in hot water, ether, alcohol, and chloroform. Its melting- 
point is 80° to 81° C. and it sublimes at 280°. It is present in vanilla 
beans to an amount varying from i to 2f per cent, and it is a curious fact 
that varieties of bean most highly prized possess the least vanillin. This 
is shovm by Ticmann and Harmann as follows: 

^Mexican beans i .69% vanillin 

Bourbon beans 2.48% " 

Java beans 2 . 75% " 

While vanillin may be readily extracted by alcohol and other solvents 
from the beans, such a product would be far too expensive to compete 
with the commercial synthetic vanillin, an artificial product, chemically 
identical with the vanillin from the bean. Synthetic vanillin was formerly 
made from the glucoside coniferin by oxidation with chromic acid. It 
is now largely obtained by oxidizing the eugenol of clove oil with alkaline 
potassium permanganate. 

If ferric chloride be added to an aqueous solution containing vanillin, 
a dark-blue coloration will be produced. 

Besides vanillin, the bean contains notable quantities of wax, fat, 
sugar, tannin, gum, and resin. 



I 



CANNED AND BOTTLED VEGETABLES, ETC. 



731 



Exhausted Vanilla Beans are sometimes found on sale, which have 
been deprived of their vanillin by being soaked in alcohol, after which 
they are coated with some artificial substitute, presenting the same frosty 
appearance as the natural vanillin crystals. This may be accomplished 
by rolling the beans in benzoic acid. Benzoic acid crystals are readily 
distinguished from those of vanillin under the microscope. 

Composition of Vanilla Extract. — Vanilla extract is a dilute alcoholic 
tincture of the vanilla bean, sweetened by cane sugar. To be perfectly 
pure it should contain no other added substances, with the possible excep- 
tion of glycerin, and many of the best brands are free from this. In 
practice it is variously prepared, but the following method of the U. S. 
Pharmacopoeia is a typical one: 

"Vanilla, cut into small pieces and bruised, 100 grams. 

"Sugar, in coarse powder, 200 grams. 

"Alcohol and water, each, a sufficient quantity to make 1,000 cc. 

"Mix alcohol and water in the proportion of 650 cc. of alcohol to 
350 cc. of water. Macerate the vanilla in 500 cc. of this mixture for 
twelve hours, then drain off the liquid and set it aside. Transfer the 
vanilla to a mortar, beat it with the sugar into a uniform powder, then 
pack it in a percolator, and pour upon it the reserved liquid. When this 
has disappeared from the surface, gradually pour on the menstruum, 
and continue the percolation, until 1,000 cc. of tincture are obtained." 

The best extracts are produced by allowing the cut beans to macerate 
in the alcohol for several months. 

Five vanilla extracts, made by Winton and Silverman from beans 
of different grades, strictly according to the pharmacopoeial formula 
as above, were analyzed by them with the following results: 



ANALYSES OF VANILLA EXTRACTS, U. S. P., MADE IN THE CONNECTICUT 
EXPERIMENT STATION LABORATORY. 



Grade of Bean. 


Specific 
Gravity. 


Vanillin. 
Per Cent. 


Alcohol 

bv 
Weight. 
Per Cent. 


Total 
Residue. 
Per Cent. 


Cane 

Sugar. 

Per Cent. 


Residue 

Other than 

Cane 

Sugar, 

Per Cent. 


Mexican (whole) 

(cut) 


i-oisg 
I. 0146 
1 . 1 og 
I. 01 66 
I. 0104 


0.125 
0.065 
0.215 
0.138 
0.108 


37-96 
39-92 
38-58 
38-32 
38.84 


22.60 
23.10 
22.00 
23-13 

21-75 


ig.90 
ig.20 
ig.oo 
20.40 
20.00 


2.70 

3-9° 
3.00 

2-73 
1-75 


South American (whole). .. 


Tahiti (whole) 





Vanillin Content. — The writer has found in his examination of a 
large number of brands of vanilla extract that gave every indication of 



73- FOOD INSPECTION AND ANALYSIS. 

purity that the content of vanillin varied from 0.05 to 0.200 per cent. 
It is rare that a pure extract will show more vanillin than the latter figure, 
though one of Winton's extracts runs as high as 0.215. The writer has 
found extracts showing 0.250 of vanillin, but believes them to have been 
reinforced with the artificial substance. It is true that the vanillin con- 
tent does not determine altogether the value of the extract, which depends 
quite as much for its virtue as a flavor upon the various resinous and 
other extractive matters which it contains, as upon the actual amount of 
vanillin present. 

Use of Alkali. — Some manufacturers employ dilute alkali, generally 
potassium bicarbonate, to aid in dissolving out the resinous matter from 
the bean, and to enable them to use a more dilute alcohol. The resulting 
product made by this process is distinctly inferior, both in taste and odor. 

Alcohol in pure extracts varies between the limits of 20 and 40 per cent. 

The Tonka Bean forms the basis of many of the cheaper so-called 
vanilla extracts on the market. It is the seed of the large tree, native to 
Guiana, known as Dipterix (or Coumaronna) odorata. The pods are 
almond-shaped, and contain a single seed, from 3 to 4 cm. long, shaped 
like a kidney bean, of a dark-brown color, having a thin, shiny, rough, 
brittle skin, and containing a two-lobed oily kernel. 

Coumarin (C^HeOj), the active principle of the Tonka bean, is the 
anhydride of coumaric acid. It occurs in the crystalline state between 
the lobes of the seed kernel. Coumarin occurs also in many other plants. 
It may be extracted from the beans by treatment with alcohol. It crj's- 
tallizes in slender, colorless needles, melting at 67° C. It has a fragrant 
odor and burning taste. It is very slightly soluble in cold water, but 
readily soluble in hot water, ether, chloroform, and alcohol. One pound 
of cut beans yields by alcoholic extraction about 108 grains of coumarin. 
The latter may be synthetically prepared by heating salicylic aldehyde 
with sodium acetate and acetic anhydride, forming aceto-coumaric acid, 
which decomposes into acetic acid and coumarin. 

The author has found that an aqueous solution of. coumarin, unlike 
vanillin, forms a precipitate when iodine in potassium iodide is added in 
excess, the precipitate being at first brown and flocculent, afterwards, 
on shaking, clotting together to form a dark-green, curdy mass, leaving 
the liquid perfectly clear. 

Tonka tincture is produced in much the same manner as the U. S. 
Pharmacopoeia vaniUa tincture, by treatment of the cut beans with dilute 
alcohol. 



CANNED AND BOTTLED yEGETABLES, ETC. 733 

The Adulteration of Vaxiilla Extract consists chiefly in the use of 
coumarin or extract of the Tonka bean, and in the substitution of artifi- 
cial vanillin, either alone or with coumarin, for the true extractives of 
the vanilla bean. The cheaper, or so-called "compound" vanilla extracts, 
more often consist of a mixture of either tincture of Tonka or coumarin 
with vanillin in weak alcohol, colored with caramel. Or the exhausted 
marc from high-grade vanilla extract is macerated with hot water and 
extracted, the extract being reinforced with artificial vanillin or coumarin, 
or both. A pure vanilla extract possesses certain pecuHarities with 
regard to its resinous content that at once distinguishes it from the artifi- 
cial, or indicates whether or not it has been tampered with. Wliilc it 
is possible to introduce artificial resinous matter in the adulterated brands, 
with a view to deceiving the analyst, it is almost impossible to do this 
without detection, since different reactions are readily apparent in this 
case from those of the pure extracts. 

Prune juice is said to be used to give body and flavor to vanilla 
extract. The writer has found spirit of myrcia or bay rum in a sample 
of alleged vanilla extract, containing also vanillin and coumarin. The 
adulterant in this sample was present to such an extent as to be unmis- 
takable by reason of the odor. 

Factitious Vanilla Extracts are ordinarily indicated (i) by the presence 
of coumarin, (2) by the peculiar reactions of cho resinous matter, or by 
the entire absence of these resins, and (3) by the abnormally low con- 
tent, or absence of vanillin. 

The following figures show the content of vanillin and coumarin in 
a few typical cheap "vanilla" extracts, selected from a large number 
examined by the author. All of these were entirely artificial, and ranged 
from 5 to 20 per cent by weight of alcohol. 

Vanillin, Coumarin, 

Per Cent. Per Cent. 

A 0.040 0.074 

B None 0.172 

C None o . 330 

D 0.250 None 

E 0.025 0.144 

As a rule these cheap artificial preparations possess considerable body 
and flavor, but the latter is of a much grosser nature than the genuine 
vanilla extract, with the delicate and refined flavor of which they are not 
to be mistaken by any one at all familiar with both varieties. 



734 FOOD INSPECT/ON AND ANALYSIS. 

The author is incHned to place 0.05% of vanillin as a minimum 
for genuine vanilla extract properly prepared, and makes a practice of 
classing as not of good standard qualijy those samples that fall 
below. 

Detection of Artificial Extracts. — The presence of coumarin or Tonka 
tincture to any appreciable extent in vanilla extract is usually recognizable 
by the odor, to one skilled in examining these ilavors. The odor of cou- 
marin is more pungent and penetrating than that of vanillin, and in mix- 
tures is apt to predominate over the milder and more delicate odor of 
vanillin. 

Add normal acetate of lead solution to a suspected extract. The 
absence of a precipitate is conclusive evidence that it is artificial. If 
a precipitate is formed, much information may be gained by its character. 
A pure vanilla extract should yield with lead acetate a heavy precipitate, 
due to the various extractives. The precipitate should settle in a few 
minutes, leaving a clear, supernatant, partially decolorized liquid. If 
onlv a mere cloudiness is formed, this may be due to the caramel present, 
and in any event is suspicious. 

Examination oj the Resins. — Resin is present in ^■anilla beans to the 
extent of from 4 to 11 per cent, and the manufacturer of high-grade 
essences endeavors to extract as much as possible of this in his product. 
This he can do by the use of 50% alcohol, in which all the resin is readily 
soluble, or by employing less alcohol and relying on the use of alkali 
to dissolve it. A pure extract free from alkali should produce a precip- 
itate, when a portion of the original sample is diluted with twice ils volume 
of water and shaken in a test-tube. 

When, moreover, the alcohol is removed from such an extract, the 
excess of resin is naturally precipitated. 

The character of the resins extracted from the vanilla bean is so dif- 
ferent from that of other resins as to furnish conclusive tests, worked 
out by Hess * as follows: 25 to 50 cc. of the extract are de-alcoholized by 
heating in an evaporating-dish on the water-bath to about one-third its 
volume. Make up to the original volume with water, and, if no alkali 
has been used in the manufacture of the preparation, the resin will be in 
the form of a brown, flocculent precipitate. To entirely set free the resin, 
acidify, after cooling, with dilute hydrochloric acid, and allow to stand 
till all the resin has settled out, leaving a clear supernatant liquid. The 
resin may be quantitatively determined, if desired, by filtering, wash- 



* Jour. Am. Chem. Soc, 21 (iSgg), p. 721, 



CANNED AND BOTTLED yEGETABLES, ETC. 735 

ing, drying, and weighing, but in this case should stand for a long time 
before filtering. 

The resin is collected on a filter, washed, and subjected to various 
tests. A piece of the filter with the attached resin is placed in a beaker, 
containing dilute potassium hydroxide. Pure vanilla resin dissolves 
to a deep-red color, and is reprecipitated on acidifying with hydrochloric 
acid. Dissolve another portion of the precipitate in alcohol, and divide 
the alcoholic solution into two portions, to one of which add a few drops 
of ferric chloride, and to the other hydrochloric acid. Pure vanilla resin 
shows no marked coloration in either case, but foreign resins nearly all 
give color reactions under these conditions. 

Tannin. — Test a portion of the filtrate from the resin for tannin by 
the addition of a few drops of a solution of gelatin. A small quantity 
of tannin only should be indicated, if the extract is pure, a large excess 
tending to show added tannin. 

Determination of Vanillin. — Vanillin may be determined (i) colorimet- 
rically, or (2) by extraction and weighing. The former is by far the 
quicker and more economical method, since it may be carried out 
directly in a ver\' small portion of the original alcoholic extract. When, 
as in some instances, the analyst has only one small bottle of vanilla 
extract for analysis, it becomes a matter of importance to use as little 
as possible for each determination. The determination of vanillin by 
both methods should give concordant results. 

(i) Colorimelrk Method* — This is carried out in the author's lab- 
oratory as follows: 2 cc. of the vanilla extract are measured into a test- 
tube, and sufficient lead hydrate is added to completely decolorize it. The 
mixture is washed upon a filter, and filtrate and washings are collected 
in a Nessler tube. Bromine water is then added, after which enough 
of a freshly prepared 10% ferrous sulphate solution is added to get the 
maximum bluish-green color that will be produced, if vanillin is present. 
A standard vanillin solution is freshly prepared by dissolving 50 mgm. 
of pure vanillin in 25 cc. of alcohol, and making up to 100 cc. with water, 
A scries of color standards is then made, taking, for instance, ^, i, ij, 2, 
2\, 3, etc., cc. of the vanillin solution in 50 cc. Nessler tubes, each being 
treated with two or three drops of bromine water, and with the ferrous 
sulphate solution, and made up to the 50-cc. mark. 

The lead hydrate is prepared by dissolving 200 grams of lead acetate 
in 850 cc. of water. The solution is filtered, a solution of potassium 

* Massachusetts State Board of Health, An. Rep., iSgg, p. 629. 



736 



FOOD INSPECTION AND ANALYSIS. 



hydroxide is added in excess, and the precipitated hydrate is washed 
thoroughly several times by decantation, or until neutral. Keep an excess 
of water in the reagent bottle, and shake up to form a heavy, white emul- 
sion before adding to decolorize. Unless the lead hydrate is washed 
free from alkali, the latter will precipitate the iron salt when added. 

If, for example, 2 cc. of a sample extract, treated as above, are found 
to give a color corresponding in depth to that produced by 5.5 cc. of the 
standard solution, the percentage of vanillin would be thus calculated: 
100 cc. standard solution contain 0.050 gram vanillin. 
I cc. " " " 0.0005 " 

5-5 cc. " " " 0.0275 " 

Since 2 cc. of the sample are equivalent to 5.5 cc. of the standard 
solution, it follows that 

2 cc. of sample contain 0.0275 gram vanillin. 
.-. 100 cc. " " " 0.1375 " 

In order to avoid calculation of each determination when a large 
number of extracts have to be examined, the following table will be found 
useful for expressing results, where the above method of procedure has 
been exactly carried out : 

Number of Cubic Centi- 
meters of Standard Equivalent 
Vanillin Solution * Per Cent of 

Corresponding Vanillin 

to 2 cc. of Sample. in Sample. 

.25 0.00625 

.5 0.0125 

.75 0.01875 

0.025 

-5 0.0375 



o 
o 
o 
I 
I 

2 
2 
3 

3 
4 
4 
5 
5 
6 

7 
8 

9 

10 



5 0.0625 

0.075 

5 0.0875 

o.i 

5 0.1125 

0.125 



0-1375 
0.15 

0-175 
0.2 
0.225 
0.25 



* 0.05 gram vanillin in loo cc. 



CANNED AND BOTTLED VEGETABLES, ETC. 737 

(2) Extraction Method* — Drive off the alcohol from 25 grams of the 
sample in an evaporating-dish on the water-bath at a temperature not 
exceeding 80° C, occasionally adding water to keep up about the original 
volume. After de-alcoholizing, add lead acetate drop by drop till all 
precipitable matter is thrown down, stir to aid the gathering of the pre- 
cipitate, filter, and wash with three portions of hot water. Cool the 
filtrate, and extract with three or four portions of 20 cc. each of ether in 
a separatory funnel, stopping the extraction when no residue is left on 
evaporating a few drops of solvent in a watch-glass. The combined 
ether extract, which contains the vanillin and coumarin, is transferred 
to a separatory funnel, and shaken out several times with 10 cc. of 2% 
ammonia. This extracts the vanillin, leaving the ether solution of 
coumarin, if present. 

Acidulate slightly the combined ammoniacal extracts with weak 
hydrochloric acid, and, after cooling, extract in a separatory funnel with 
ether till exhausted of its vanillin, evaporate off the excess of ether sponta- 
neously in a tared platinum dish, dry over sulphuric acid in a desiccator, 
and weigh. Identify the residue as vanillin by the melting-point (8i°- 
82° C), by odor, by appearance of the crystals both megascopically and 
microscopically, and by testing in aqueous solution with ferric chloride, 
which should yield a dark-green coloration. If, however, the form of 
crystallization is not conclusive, or if the crystals are colored or accom- 
panied by amorphous matter, without disturbing the residue, extract it in 
the dish with various portions of boiling petroleum ether till all the 
vanillin is removed, decanting each portion into a dry beaker. 

The dish is again dried, this time at 100°, and weighed. If any residue 
is found, it is deducted from the first figure. The second treatment is 
rarely found necessary. 

Determination of Coumarin. — Transfer the original ether solution 
(from which the vanillin was removed by ammonia) to a tared platinum 
dish, evaporate off the ether at room temperature over sulphuric acid 
in a desiccator, and weigh. Here, as in the case of vanillin, the character 
and appearance of the crystals will indicate whether or not foreign matter 
is present with the coumarin. If pure, the crystals should be perfectly 
white and well formed, and no dark-colored matter should be present. 
The odor of the pure coumarin is unmistakable, and the melting-point 
(67° C.) as well as the microscopical appearance may serve to identify 

* Winton's Modification of Hess and Prescott's Method, Jour. Am. Chem. Soc, 21, 
1899, p. 257; ibid., 24, 1902, p. 1 1 29. 



738 FOOD INSPECTION AND ANALYSIS. 

it. If there is doubt as to the purity of the first residue, without dis- 
turbing it by tests, extract with boiling petroleum ether, and correct in 
the same manner as directed for vanillin. 

In case the colorimetric method for vanillin was used, and coumarin 
only is to be separated for gravimetric determination, the author has 
found that good results are usually obtained by simply treating the de- 
alcoholized original sample with ammonia, extracting it with 3 or 4 
portions of chloroform in a separatory funnel, and evaporating the com- 
bined chloroform extract in a tared dish at a temperature not exceeding 
60° in the oven. 

If the residue is small, or if in any case there is some doubt as to 
whether or not any coumarin is present therein, apply the author's test 
for coumarin as follows: Add a few drops of water, warm gently, and 
add to the solution a little iodine in potassium iodide, reagent No. 143. 
In presence of coumarin a brown precipitate will form, which on stirring 
with the rod will soon gather in dark-green flecks. The reaction is 
especially marked if done on a white plate or tile. Many of the pre- 
cautions employed in carrying out the above processes for vanillin and 
coumarin determination may be dispensed with, if these substances are 
simply to be tested for qualitatively. 

Vanillin and Coumarin Crystals Under the Microscope. — These sub- 
stances are best examined when crystallized from ether solution, and 
several crj'stallizations may be found necessary, before the best results 
are obtained. For examination, pour a few drops of the ether solution 
of the purified vanillin or coumarin directly on a slide, and allow to evap- 
orate spontaneously. Under best conditions vanillin crystallizes from 
ether in long, slender needles, often radiating from central points, or 
forming star-shaped bundles. 

Courmarin crystals are shorter and thicker than vanillin. 

With polarized light pure vanillin crystals give a brilliant play of 
colors between crossed nicols, even without the selenite plate, while pure 
coumarin crystals without the selenite are almost lacking in varying 
colors, and show very little play, even when the selenite is employed. This 
sharp distinction is not true, when crystallized from chloroform. 

Determination of Glycerin. — The presence of any considerable quantity 
of glycerin is apparent by the character of the residue obtained on evaporat- 
ing 5 grams to drj'ness, in the determination of total solids. The residue, 
if glycerin is present \n notable amount, appears of a moist consistency, 
even when a practically constant weight has been attained at 100° C. 



C/INhlED AND BOTTLED VEGETABLES,' ETC. 739 

To determine glycerin, proceed as with wines (p. 570). 

Determination of Alcohol. — Measure out 25 cc. of the sample, dilute 
to 50 cc. with water, and distill off about 20 cc. in a 25-cc. graduated receiver. 
, Make up to the mark with water, determine the specific gravity at 15.6°, 
and find from the alcohol table the per cent corresponding. 

Cane Sugar and Glucose are determined as in the case of preserves 
and jellies. 

Caramel is best detected by Crampton and Simons' method with 
fullers' earth (p. 603). 

Lemon Extract. 

Lemon extract, the Spiritus limonis or essence of lemon of the 
Pharmacopceia, is directed to be made in the following manner: 

" Oil of lemon 50 cc. 

" Lemon peel freshly grated 50 grams 

"Deodorized alcohol, a sufficient quantity to make 1000 cc. 

"Dissolve the oil of lemon in goo cc. of deodorized alcohol, add the 
lemon peel, and macerate for twenty-four hours. Then filter through 
paper, and add, through the filter, enough deodorized alcohol to make 
the spirit measure 1000 cc." 

The standard fixed by the Pharmacopoeia (5% of lemon oil by volume) 
is a fair one. In fact there are commercial extracts on the market con- 
taining as high as 9%. An extract of lemon to contain 5% of lemon 
oil must contain at least 80% by volume of alcohol, lemon oil being 
unsoluble in dilute alcohol. Deodorized, or purified alcohol, commonly 
known as cologne spirits or perfumers' alcohol, is used in the highest- 
grade preparations, since the odor of ordinary commercial alcohol pro- 
duces a slightly deleterious effect. 

Though there are many reputable brands of lemon extract on sale 
containing 5% or more of lemon oil, the market is flooded with the 
cheaper "ten-cent" variety, many purporting to be pure, others marked 
simply "compound," and others again with formulas having the name 
and per cent of the ingredients. 

The classification of these extracts, whether as pure or adulterated, 
depends largely on the local laws in any particular state. 

Adulteration of Lemon Extracts. — For making a cheap extract the 
cost of the lemon oil is not so important an item as that of the alcohol, 
and as little as possible of the latter is employed, though pure oil is doubt- 



74° FOOD INSPECTION /1ND ANALYSIS. 

less used. The average cheap extract is made by rubbing the oil in 
carbonate of magnesia in a mortar, stirring in slowly a little strong alcohol, 
and allowing the mixture to soak for some time. A varying amount 
of water is added a little at a time, and the whole is shaken and again 
allowed to stand, sometimes for a week, before filtering. Finally the 
extract is filtered and the coloring matter added, consisting sometimes of 
turmeric tincture and sometimes of coal-tar dyes. In these cheap extracts 
the per cent of alcohol often runs below 40, and as little as 4.5% by 
volume of alcohol has been found by the author in a commercial extract. 
With less than 45% of alcohol by volume, no appreciable amount of oil 
is dissolved, only the merest traces, though such preparations are fre- 
quently bottled as "pure extract of lemon." Time and again manu- 
facturers have protested to the author that the purest oil was used by 
them, when notified that their brand contained no oil, or when prosecuted 
in court, and were with difficulty convinced that the trouble with their 
goods was that, on account of weak alcohol employed, the lemon oil used 
failed to get into the final product. It is true that a certain taste or odor 
of the lemon is present, even in the cheap varieties wherein no oil is 
found, due to the fact that even dilute alcohol, when slowly percolating 
through the magnesia in which the oil is finely distributed, does abstract 
therefrom a suggestion of the flavor, which is, however, but a mere shadow 
of the substance and body possessed by a strong alcoholic solution of oil 
of lemon. 

In many instances, where formulas appear stating the name and 
per cent of ingredients, these formulas are entirely deceptive and mis- 
leading, in that the statements are not borne out on analysis. 

Few manufacturers, for example, are prepared to state boldly that 
their product contains no oil of lemon, a condition which in this class 
of goods is often the case. 

The flavor of the cheap extracts is sometimes reinforced by the addi- 
tion of such substances as citral, oil of citronella, and oil of lemon grass, 
but minute quantities only of these pungent materials can be used, not 
exceeding 0.33% in the case of citral and 0.1% in the case of the two 
last mentioned oils. Cane sugar and glycerin are sometimes found. 

The Pharmacopoeia provides for the coloring of lemon extract by 
the use of lemon peel. This gives a rich ycUow color, but one that 
readily fades. Other coloring matters employed are largely coal-tar 
dyes, and occasionally tincture of turmeric. 

During 1901 practically all the brands of lemon extract sold in Massa- 



C/1NNED AND BOTTLED yEGET/IBLES, ETC. 



741 



chusetts were collected and analyzed. 167 samples were examined, 
representing about 100 brands, and 139 samples were classed as adul- 
terated, based on 5% lemon oil as a standard, and depending on whether 
or not the contents conformed to the labels on the bottles. 

The following are typical analyses, selected from the tabulated results 
of the above examination : * 



LEMON EXTRACTS OF STANDARD QUALITY. 



Polarization 


Lemon Oil. 


Specific 


Alcohol, 




in 200-mm. 


Per Cent by 


Gravity at 


Per Cent by 


Foreign Ingredients. 


Tube, 


Volume. 


:S.6°C. 


Volume. 




30.8 


9.1 


0.8280 


84.39 


Turmeric 


26.0 


7.6 


0.8402 


80.49 




23-5 


6.9 


0-8352 


81.74 


Dinitrocresol 


21.8 


6.4 


0.8396 


82.88 




20.0 


5-9 


0-8335 


84.24 




18.0 


5-3 


0.8268 


86.82 




17.0 


S-o 


0.8496 


80.06 





INFERIOR OR ADULTERATED LEMON EXTRACTS. 



Polarization 


Lemon Oil, 


specific 


Alcohol, 




in 200-nini. 


Per Cent by 


Gravity at 


Per Cent by 


Foreign Ingredients. 


Tube. 


Volume. 


15.6° C. 


Volume. 




14.0 


4-1 


o.8t;92 


77.62 


Dinitrocresol 


12.2 


3-6 


0.8644 • 


76.08 


" 


II. 


3-1 


0.8620 


77-50 


A coal-tar dye 


Q.9 


2.9 


0.8615 


77.90 




8.0 


2-3 


0.8531 


81.61 


Dinitrocresol 


6.8 


2.0 


0.8416 


87-55 


Tropsolin 


5-0 


1-5 


0.8832 


71. IQ 


** 


3-5 


I.O 


0.8939 


67.68 




2.8 


0.8 


0.8995 


65 • 23 


Dinitrocresol 


2.2 


0.6 


0.8941 


67.69 


" 


1.4 


0.4 


0.9136 


59-40 


A nitro dye 


0.3 


0. 1 


0.9408 


46.40 


Dinitrocresol 


0.0 


0.0 


0-9937 


4-49 


Tropxolin 


-8.0 


0.0 






Invert sugar 


27.0 


0.0 




27.49 


Cane sugar 


0.0 


0.0 




47-35 


Oil other than lemon 



Forty-two samples contained no lemon oil, ranging in content of 
alcohol from 4 to 45 per cent. 

Methods of Analysis. — A. S. Mitchell was the earliest worker who 
systematically examined lemon extract, and to him are due the methods 
for determining oil of lemon, as well as various other tests now adopted 
provisionally by the A. O. A. C.f 

* An. Rep. Mass. State Board of Health, 1901, p. 459; Food and Drug Reprint, p. 41. 
t Jour. Am. Chem. Soc, 21, 1899, p. 1132; U. S. Dept. of Agric, Bur. of Chem., BuL 
65. P- 73- 



742 FOOD INSPECTION AND ANALYSIS. 

Detection of Oil of Lemon. — If on adding a large excess of water 
to a little of the extract in a test-tube no cloudiness occurs, the oil may 
fairly be inferred to be absent. The degree of cloudiness produced is 
proportional to the amount of lemon oil present. 

Determination of Lemon Oil. — Mitcheirs Methods. — (i) By Polariza- 
tion. — Polarize the undiluted extract in a 200-mm. tube at 20° C. Divide 
the reading on the Ventzke cane sugar scale by 3.4, and if cane sugar 
or other optically active substances arc absent, the quotient expresses 
the per cent of lemon oil by volume. With instruments reading in circular 
degrees, divide the rotation in minutes at 20° C. by 62.5. If the Laurent 
instrument with sugar-scale is used, divide the sugar-scale reading by 4.8. 

Cane sugar, though rarely found in lemon extract, is occasionally 
used in small amount. It is said to aid in the solution of the oil. If it 
is present, wash the solid residue from 10 cc. of the sample (dried on 
a water-bath) with three portions of 5 cc. each of ether, to remove waxy 
and fatty matters, dry and weigh the residue of cane sugar, deducting 
0.38 from the reading for each 0.1% of sugar so found. 

(2) By Precipitation. — Transfer by a pipette 20 cc. of the extract 
to a Babcock milk-flask, add i cc. of dilute hydrochloric acid (1:1); add 
25 to 28 cc. of water previously warmed to 60° C; mix, and stand in 
water at 60° for five minutes; whirl in a centrifuge for five minutes; fill 
with warm water to bring the oil into the graduated neck of the flask, 
and repeat the whirling for two minutes; stand in water at 60° for a few 
minutes, and read the per cent of oil by volume. Where the oil of lemon is 
present in amounts over 2%, add to the percentage of oil found 0.4% 
to correct for the oil retained in solution. Where less than 2% and more 
than 1% is present, add 0.3% for correction. 

Save the precipitated oil for the determination of refraction. 

When the extract is made in accordance with the U. S. Pharmacopoeia, 
the results by the two methods just given should agree within 0.2%. 

To obtain per cent by weight from per cent by volume, as found by 
either of the above methods, mulliply the volume percentage by 0.86, and 
divide the result by the specific gravity of the original extract. 

Determination- of Alcohol. — Mitchell has shown that the difference 
in specific gravity between oil of lemon and stronger alcohol is not so 
great, but that a very close approximation to the true percentage of alcohol 
in lemon extracts may be obtained from the specific gravity itself, assum- 
ing, of course, that foreign substances, such as sugar, glycerin, etc., are 
absent. In the absence of such foreign substances determine the specific 



CANNED AND BOTTLED yEGETABLES, ETC. 743 

gravity of the sample, ascertain from the alcohol tables on pages 531, 
544, the per cent of alcohol by volume corresponding. This gross figure 
includes the lemon oil, the per cent of which should be deducted for 
the correct per cent of alcohol. 

In the absence of oil of lemon, a measured portion of the original 
sample may be distilled, and the percentage of alcohol determined from 
the distillate in the usual manner, but when lemon oil is present, this 
should first be removed by diluting 50 cc. of the extract to 200 with water, 
and shaking the mi.xture with 5 grams of magnesium carbonate in a 
flask, iiltering through a dry filter, and determining the alcohol by distil- 
lation in a portion of the filtrate. The result is multiplied by 4 to correct 
for the dilution. 

Methyl Alcohol has been used by unscrupulous manufacturers in 
lemon extracts. IMethyl alcohol is best detected by the method of 
MuUiken and Scudder,* depending on conversion of the methyl alcohol 
to formaldehyde. 

Dilute a portion of the distillate obtained in the determination of 
alcohol (or, for preliminary examination, dilute and filter the original 
extract) until the liquid contains approximately 12% of alcohol by weight. 

Oxidize 10 cc. of the liquid in a test-tube as follows: Wind copper 
wire I mm. thick upon a rod or pencil 7 to 8 mm. thick, in such a manner 
as to inclose the fixed end of the wire and to form a close coil 3 to 3.5 cm. 
long. Twist the two ends of the wire into a stem 20 cm. long, and bend 
the stem at right angles about 6 cm. from the free end, or so that the 
coil may be plunged to the bottom of a test-tube, preferably about 16 mm. 
wide and 16 cm. long. Heat the coil in the upper or oxidizing flame of 
a Bunsen burner to a red heat throughout. Plunge the heated coil to 
the bottom of the test-tube containing the diluted alcohol. Withdraw 
the coil after a second's time and dip it in water. Repeat the operation 
from three to five times, or until the iilm of copper oxide ceases to be 
reduced. Cool the liquid in the test-tube meanwhile by immersion in 
water. 

Test for Formaldehyde. — Divide the oxidized liquid in the test-tube 
into two parts, testing one for. formaldehyde with pure milk by the hydro- 
chloric acid and ferric chloride test. Test the other portion by MullLken 
and Scudder's resorcin test for formaldehyde, page 666, avoiding an ex- 
cess of the reagent. t 

* Am. Chem. Jour., 21, 1899, p. 266. 
y Ibid., 24, 1900, p. 451. 



744 FOOD INSPECTION /IND /INALYSIS. 

Tests for Colors. — Evaporate a portion of the sample to dryness, 
dissolve the residue in water, and extract coal-tar colors if present by 
Arata's method, page 641, or with hydrochloric acid. 

Much information may often be gained by treatment of the original 
extract with strong hydrochloric acid. If the color employed be turmeric 
or naphthol yellow, no change in color will be evident on addition of 
the acid. If tropaeolin or methyl orange is present, the solution will turn 
pink, while partial decoloration of the solution indicates Martius yellow, 
and complete decoloration shows presence of dinitrocresols. 

Test for turmeric by boric acid, page 637. 

Determination of Total Solids and Ash. — Total Solids are estimated 
by evaporating on the water-bath 10 grams of the sample in a tared dish, 
and drying at 100° to constant weight. If glycerin be present, it is dif- 
ficult if not impossible to get a constant weight. Cane sugar and glycerin, 
if present, will be apparent in the residue. If capsicin has been used, 
it will be noticed by the taste. 

Burn to an ash the residue from the solids in a mufHe at a low red 
heat, cool in a desiccator, and weigh. 

Glycerin is determined as in wine, page 570. 

Detection of Tartaric or Citric Acid.— To a portion of the extract 
in a test-tube add an equal volume of water to precipitate the oil. FiUer 
and add one or two drops of the filtrate to a test-tube half full of cold, 
clear lime water. If tartaric acid is present, a precipitate will come 
down, which is soluble in an excess of ammonium chloride or acetic acid. 

Filter off the precipitate, or, if no precipitate is visible, heat the con- 
tents of the tube. Citric acid will precipitate in a large excess of hot 
lime water. 

Examination of Lemon Oil. — The oil separated from the extract in 
the process of determining the lemon oil by precipitation (p. 742), is 
most readily examined for its purity, after drying with calcium chloride, 
by determination of its specific gravity, its index of refraction, or its 
refractometric reading with the Zeiss butyro-refractometer, and its polari- 
scopic reading. 

The specific gravity and refractometric readings are determined as 
with fixed oils, using with the butyro-refractometer a sodium flame or 
yellow bichromate color-screen, which gives perfectly sharp readings 
without dispersion. 

The following table shows readings on the Zeiss butyro-refractometer 
of pure lemon oil at various temperatures, using the sodium light. 



CANNED AND BOTTLED VEGETABLES, ETC. 745 

READINGS ON ZEISS BUTYRO-REFRACTOMETER OF LEMON OIL. 



Tempera- 


Scale 


Tempera- 


Scale 


Tempera- 


Scale 


Tempera- 


Scale 


ture. 
Centigrade. 


Reading. 


ture. 
Centigrade. 


Reading. 


ture. 
Centigrade. 


Reading. 


ture. 
Centigrade. 


Reading. 


40.0 


59-4 


35-° 


62.8 


30.0 


66.3 


25.0 


69.7 


39-S 


59-7 


34-5 


63-1 


29-5 


66.6 


24-S 


70.0 


39-0 


60.1 


34-0 


63-5 


29.0 


67.0 


24.0 


70.4 


38-5 


60.4 


i3-S 


63.8 


28.S 


67-3 


23-5 


70.7 


38.0 


60.8 


33-0 


64.2 


28.0 


67.7 


23.0 


71. 1 


37-5 


61.0 


32-5 


64.5 


27-5 


68.0 


22.5 


71-4 


37-° 


6r.s 


32.0 


64.9 


27.0 


68.4 


22.0 


71.8 


36.5 


61.8 


31-5 


65 -I 


26.5 


68.7 


21-5 


72.1 


36.0 


62.1 


31.0 


65.6 


26.0 


69.0 


21.0 


72-S 


35-5 


62.4 


3°-5 


65.9 


25-5 


69-3 


20.5 


72.8 


35-° 


62.8 


30.0 


66.3 


25.0 


69.7 


20.0 


73-2 



For examination of high polarizing essential oils like oil of lemon, the 
author employs a 50-mm. tube, in order to get readings on the undiluted 
oil well within the limits of the cane sugar scale on the polariscope. If 
such a tube is not available, dilute the oil with an equal volume of alcohol, 
and use the loo-mm. tube. The following table expresses constants 
of pure lemon oils and of various commonly employed adulterants, as 
determined in the laboratory of the Massachusetts State Board of Health : 

CONSTANTS OF SOME ESSENTIAL OILS. 



Oil. 



Butyro-refractometer 
(Sodium Light) at — 



Temp. 



Reading. 



Rotation 
in 100- 
Millimeter 

Tube, 
Ventzke 

Scale. 



Specific 

Gravity 

at IS. 6° C. 



Oil of lemon (lowest) 

" " " (highest) 

" " " grass (A. Giese) 

" " citronella (A. Giese) 

Terpeneless oil of lemon (Hansel's) 

" " " " grass (Hansel's) 
Citral (A. Giese) 



25- 
25- 

22.5 
22.5 
23- 

23- 

22.5 



69 

71 
96 

87 
87 
91 
95 



173-° 

184.5 

-10.8 



-5-6 
-3-6 



0.8580 
0.8610 
0.9309 

0-9437 
0.9463 
0.9232 
0.9296 



Oil of Lemon is a light-yellow liquid, having the pleasant odor of 
fresh lemons, and an aromatic, mild, somewhat bitter after taste. It 
is obtained from the grated rind of the lemon either by treatment with 
hot water, skimming off the oil which rises to the surface, or by pressure, 
or by distillation with water. It is rapidly changed by action of air and 
light, becoming "terpeney," and under these conditions its solubility 
in alcohol seems to increase. Its composition is somewhat uncertain, 
but according to Wallach * nearly 90% consists of hydrocarbons, mostly 



* Liebig's Annalen, 227, p. 290. 



746 FOOD INSPECTION AND ANALYSIS. 

terpenes, the most important of which is the terpene hmonene * of the 
dextro-gyrate variety, also known as citrene. 

Another important constituent of lemon oil is the aldehyde citral, 
present to the extent of from 7 to 10 per cent. To this the odor of the 
oil is largely due. A second aldehyde, citronellal, is also present in lemon 
oil. 

A frequent adulterant of lemon oil is turpentine oil, which lowers 
the rotation considerably, and is thus most easily rendered apparent. 

Citral (CioHigO) is an aldehyde present in lemon oil and in oil of lemon- 
grass, and, while it may be separated from these oils, is prepared artifi- 
cially by oxidizing geraniol with chromic acid.f It is a mobile oil, and 
when perfectly pure is optically inactive. The commercial citral is, 
however, slightly la;vo-rotan,', due no doubt to impurities. 

Oil of Lemon-grass is distilled from lemon-grass, Andropogon cUratus 
(D. C), cultivated in India. It is reddish yellow in color, and has an 
intense lemon-like odor and taste. Very little is known of its composi- 
tion, but it seems to contain several aldehydes, one of which is citro- 
nellal, and another citral. The latter, however, is its chief constituent, 
being present to the extent of 70 to 75 per cent. 

Citronellal (CjoHigO) is an aldehyde found in various oils, especially 
in citronella oil, from which it is readily separated. It is made artificially 
by the oxidation of the primary alcohol citronellol (CjoHjoO). It is 
quite strongly dextro-rotary. 

Oil of Citronella is distilled from the grass Andropogon nardus (L.j, 
growing chietly in Ceylon, India, and tropical East Africa. It is a yel- 
lowish-brown liquid with a pleasant and lasting odor. Citronellal is 
present in this oil to the extent of from 10 to 20 per cent, and the oil 
contains also from 10 to 15 per cent of terpenes, among which are 
camphene. 

Tests for Citral, Citronellal, and Limonene.J — Reagent. — Ten grams 
of mercuric sulphate are dissolved in sufficient 25% sulphuric acid to 

make 100 cc. 

Shake 2 cc. of the sample to be examined in a corked test-tube with 
c cc. of the reagent. Citral yields a bright-red color, which rapidly dis- 
appears, leaving a whitish compound, which floats on top. Citronellal 
forms a bright-yellow color, remaining for some time. 

♦There are two limonenes, ■ one of which is dextro- and the other Isevo-rotary. The 
two are completely alite in their behavior, differing only in their optical rotation. 
tTiemann, Berichte, 31, p. 33"- 
t Burgess, Chem. and Drugg., 57, p. 732- 



CANNED AND BOTTLED VEGETABLES, ETC. 



747 



Limonene forms an evanescent, faint flesh color, and leaves a white 
compound. 

MISCELLANEOUS FLAVORING EXTRACTS. 

A much larger variety of flavors are used in confectionery and soda- 
water syrups than are required by the housewife in ordinary cookin^. 
These miscellaneous flavors may be divided into two classes, first those 
which, like lemon essence, are alcoholic extracts of oils, including such 
essences as orange, clove, nutmeg, ginger, mace, cassia, peppermin:, 
spearmint, wintergreen, and almond; and second, those which are made 
up of artificial fruit essences or compound ethers, which are ingeniouslv 
mixed to imitate the pure fruits. Under this class are included such 
flavors as strawberry, raspberry, pineapple, cherry, banana, pear, rose, 
peach, plum, apricot, and quince. 

In the case of extracts of oils, it is generally practicable to separate 
the oil for examination by the centrifuge, as in the precipitation method 
of Mitchell and to estimate the same directly as described on page 742, 
when the specific gravity of the oil in question is less than water. In 
the case of such oils as clove, wintergreen, and cassia, where the specific 
gravity is greater than water, it is necessary to add salt to the extract before 
centrifuging, to cause separation of the oil. 

The following table shows the specific gravity and polarimetric reading 
of these "essence" oils: 



Specific Gravity. 



Polarization loo mm, 
Ventzke Scale. 



,a.t 3s°C. 



Orange 

Clove 

Nutmeg -. . . . 

Spearmint 

Peppermint 

Wintergreen. . . . 

Cassia bark 

Mace 

Ginger 

Almonds (bitter) 



i to 0.852 



I -045 

0.865 


1.070 
' 0.920 


O.Q2 


' 0.98 


0.90 
I. 180 
I -055 


' 0.925 
' I. 187 
' I -065 


O.QI 

0.875 

1-045 


' 0.93 
' 0.885 
' 1.06 



276.8 to 282.6 
■ -3-8 
40.0 ' 86.5 
— 104.0 " —138.0 
-72.0 " -95.2 
Inactive 
Very slightly laevo-gyrate 
29.0 to 58.0 
-75.6 " -126.9 
Inactive 



1-4774 
1-5245 
1-4763 
1.4792 

1-4550 
1.4299 

1-5925 
1-4774 

1-5373 



With the exception of oil of orange, these oils vary so widely in their 
optical rotation as to be incapable of being estimated in extracts by the 
polarimetric method described for lemon oil. 



748 FOOD INSPECTION AND ANALYSIS. 

ORANGE EXTRACT. 

Orange oil is a yellowish liquid, having the characteristic odor of 
orange, and a mild aromatic taste. It is prepared from orange peel in 
an analogous manner to that of lemon oil, which it somewhat resembles 
in chemical composition. At least 90% of orange oil, according to Wal- 
ach, consists of dextro-limonene (citrene). It has a much higher specific 
rotary power than lemon oil. For the determination of oil in orange 
extract, follow the method given for oil in lemon extract, page 742, 
dividing the direct polarimctric reading on the Ventzke scale, calculated 
for the 200-mm. tube, by 5.3 to obtain the per cent of orange oil, by volume. 
To obtain the per cent by weight, multiply the per cent by volume by 
0.85 and divide by the specific gravity of the extract. 

ALMOND EXTRACT. 

Essence of bitter almonds, or Spiritus amygdalcB antara, is thus pre- 
pared according to the U. S. Pharmacopoeia: 

Oil of bitter almonds 10 cc. 

Alcohol 800 cc. 

Distilled water sufficient to make 1000 cc. 

Thus 1% of almond oil is present in the product. 

Oil of bitter almonds is obtained by subjecting crushed bitter almonds 
or apricot seeds to distillation with water. It should be remembered 
that both sweet and bitter almonds yield a bland fixed oil on pressure, 
which is not to be confounded with the volatile oil yielded on distillation 
of the bitter almonds after the fixed oil has been pressed out. Bitter 
almonds contain a glucoside, amygdalin, together with a ferment known 
as emulsin or synaptase, which, acting on the amygdalin in the distil- 
lation produces benzaldehyde and hydrocyanic acid as follows: 

CooH„NOi, + 2H2O = C,HeO + HCN + 2CeH,,06. 

Amygdalin Benzalde- Hydro- Glucose 

hyde cyanic acid 

The unpurified oil of bitter almonds consists of benzaldehyde, with 
a small amount of the highly poisonous hydrocyanic acid. Nearly all 
of the commercial oil is made from the cheaper apricot and peach seeds 
rather than those of the bitter almond, but the product is practically 
identical. The oil is freed from hydrocyanic acid by agitating with cal- 
cium hydrate and a. solution of ferrous chloride, distilling the mixture, 
and drying the oil which comes over with calcium chloride. 



CANNED AND BOTTLED' VEGETABLES, ETC. 749 

Benzaldehyde or purified oil of bitter almonds has a yellowish color, 
a bitter, acrid, burning taste, and a marked almond odor. The specific 
gravity of the crude oil varies from 1.052 to 1.082, while that of the purified 
oil (benzaldehyde) at 20° is 1.0455. ^^s boiling-point is 180° C. On 
standing it becomes readily oxidized to benzoic acid. It is readily soluble 
in alcohol and ether. Its solubility in water is slight, i : 300. Its index 
of refraction at 20° C. is 1.5446. It should be noted that the refractive 
indices of almond oil, whether with or without hydrocyanic acid, and of 
artificial benzaldehyde are nearly the same. 

Benzaldehyde is produced artificially in a variety of ways, but is 
chiefly prepared by the action of chlorine on hot toluene. The result- 
ing benzyl chloride is distilled with lead nitrate and water in an atmos- 
phere of carbon dioxide, which forms benzoic aldehyde. Synthetic 
benzaldehyde has the same properties as the purified oil of bitter almonds, 
and has largely displaced it in the market, not the least of its advantages 
being its freedom from hydrocyanic acid. 

Adulteration of Almond Oil. — The official essence of the Pharmacopoeia 
does not specify that the almond oil used be perfectly free from hydro- 
cyanic acid, in spite of the fact that its highly poisonous nature is well 
known, and that it exists in the crude oil to the extent of from 4 to 6 per 
cent. True, but little of it is found in the extract, but in these days, when 
the unannounced presence in foods of such substances as antiseptics 
and coloring matters is regarded as questionable from a sanitary stand- 
point, in spite of the fact that their toxic effects on man are still matters 
of controversy, there should be little hesitancy in pronouncing the presence 
of prussic acid objectionable, especially when a pure almond oil entirely 
free from it is readily obtainable. 

The presence of nitrobenzol or oil of mirbane as a substitute of 
almond oil is to be looked for. This substance is sometimes, though 
incorrectly, called artificial oil of bitter almonds. It is a heavy, yellow 
liquid of the composition CgHsNOs, readily soluble in water. Its specific 
gravity at 20° C. is 1.2039. I's boiling-point is 205° C. It is formed 
by the action of nitric acid on benzol. It possesses a highly pungent 
odor, somewhat like that of oil of bitter almonds, though more penetrating 
and less refined. Its index of refraction at 20° C. is 1.5517. 

Detection of Nitrobenzol.* — Boil 15 cc. of the extract in a test-tube 
with a few drops of a strong solution of potassium hydroxide. Nitro- 
benzol produces a blood-red coloration. 

* Holde, Jour. Soc. Chem. Ind., 13 (1893), p. 906. 



750 FOOD INSPECTION AND ANALYSIS. 

Distinction between Benzaldehyde and Nitrobenzol. — Treat 20 cc. 
of the extract with 5 to 10 cc. of a cold, saturated aqueous solution of 
sodium bisulphite in a test-tube, and shake vigorously. Transfer to 
an evaporating-dish, and heat on the water-bath till the alcohol is driven 
off. At this stage benzaldehyde remains in the hot solution as a crystal- 
line salt, and the solution gives off no almond odor. 

Nitrobenzol, on the contrary, does not combine with the bisulphite 
and is insoluble, forming globules of oil on the surface of the hot liquid, 
and in addition giving off the pungent odor so characteristic of the sub- 
stance. 

Determination of Benzaldehyde. — In case nitrobenzol by the quali- 
tative test is found to be absent, shake vigorously 50 cc. of the extract 
with 20 cc. of the saturated sodium bisulphite sclution in a stoppered 
flask, transfer to an evaporating-dish, and heat on the water-bath till the 
alcohol has disappeared, keeping up the original volume by the occa- 
sional addition of water. Note the odor of the solution at frequent inter- 
vals during evaporation, and if at any time the least odor of escaping 
benzaldehyde is apparent, stir in at once a few drop's more of the bisul- 
phite solution. Cool, dilute with water slightly, make strongly alkaline 
with sodium hydroxide, and extract in a separatory funnel with four 
portions of low-boiling petroleum ether of 15 to 20 cc. each. Wash the 
combined petroleum ether twice with water, and, after removal of the 
water, transfer it to a tared dish, and allow it to evaporate spontaneously 
at room temperature. Finally weigh the residue. 

By reason of the volatility of benzaldehyde and its tendency to oxidize 
to benzoic acid, the results arc only approximate. 

Separation of Nitrobenzol and Benzaldehyde. — If by the qualitative 
test nitrobenzol is found, shake vigorously as before 5c cc. of the extract 
with ID cc. of the saturated sodium bisulphite solution in a corked flask, 
and transfer with 100 cc. of water to a large separatory funnel. Shake 
out the nitrobenzol from the solution with four successive portions of 
petroleum ether of 15 to 20 cc. each, and after washing with water the 
combined petroleum ether, transfer it to a tared dish, in which it is allowed 
to evaporate spontaneously. 

It is extremely difficult to avoid loss of some of the nitrobenzol by 
this process, but even if the weighed residue fails to show the full amount 
originally used, enough will usually be extracted to admit of testing on 
the refractometer, and of otherwise verifying its character. 

After removal of the nitrobenzol, make the residual solution in the 



CANNED y^ND BOTTLED (VEGETABLES, ETC. 751 

separatory funnel strongly alkaline with sodium hydroxide, and shake 
out the benzaldchydc, if present, with petroleum ether as previously 
described. If after making the solution alkaline no odor of benzalde- 
hyde is apparent, the absence of benzaldehyde may be inferred. 

Distinction between Artificial Benzaldehyde and Pure Almond Oil. — 
Test the final residue from the ether extract by shaking witli an equal 
volume of concentrated sulphuric acid in a test-tube. With natural 
oil of almonds a clear, brilliant, but dark currant-red color is produced, 
while with artificial benzaldehyde,. the acid produces a dirty brown color 
with the formation of a precipitate. 

Determination of Alcohol. — In the absence of other flavoring sub- 
stances than nitrobenzol and benzaldehyde, which are rarely present 
to an extent exceeding 1%, a suflrcicntly close approximation for most 
purposes can be gained by estimating the alcohol from the direct specific 
gravity of the extract. 

Detection of Hydrocyanic Acid. — To a few cubic centimeters of 
extract in a test-tube add a few drops of a mixture of solutions of ferrous 
sulphate and ferric chloride, the ferrous salt being in excess. Make 
alkaline with sodium hydroxide, and add enough dilute hydrochloric 
acid to dissolve the precipitate formed by the alkali. Presence of a blue 
coloration or precipitate, due to the formation of Prussian blue, indicates 
hydrocyanic acid. The reaction is very delicate. ■ 

Determination of Hydrocyanic Acid.* — Hydrocyanic acid may be 
determined by titration with tenth-normal silver nitrate solution. 25 cc. 
of the extract are measured into a flask, and 5 cc. of freshly prepared 
magnesium hydroxide suspended in water are added, or enough to 
make the reaction alkaline. 

A few drops of a solution of potassium chromate are then introduced, 
and the tenth-normal silver nitrate solution added till, with shaking, the 
formation of the red silver chromate indicates the end-point, i cc. of 
silver solution equals 0.0027 gram of hydrocyanic acid. 

ARTIFICIAL FRUIT ESSENCES. 

Nearly all the fruits possess distinctive flavors, which are desirable 
in food preparations, and which may be made to impart their flavor to 
such substances as confections, ice cream, dessert mixtures, jellies, etc., 
by simply mixing with these foods the fresh or preserved fruit or fruit 
juice in sufficient quantity. In many cases, however, it is not found 
* Vielhaber, Arch. Phann. (3), 13, 408. 



75* FOOD INSPECTION AND /INALYSIS. 

possible or practicable to prepare from the fruits themselves an extract 
sufficiently concentrated to give the distinctive fruit flavor, when used 
in moderate quantity, and hence the use of artificial fruit essences made 
up of compound ethers, mixed in varying combinations and proportions 
to imitate more or less closely various fruit flavors. 

These ethers are usually much more pungent and penetrating than 
the fruits which they imitate, and, while lacking the delicacy and reiine- 
ment of the original fruits, serve to impart a certain semblance of the 
genuine flavor in a convenient and highly concentrated form. 

Some of the single compound ethers possess a remarkable resemblance 
to particular fruits, while to imitate other fruits a mixture of various 
ethers and flavoring materials, such as lemon and other volatile oils, 
vanilla, organic acids, chloroform, etc., is necessary. These artificial 
essences should in all cases be sold as such, and not as "pure fruit flavors." 

Artificial Pineapple Essence is made up by dissolving in alcohol butyric 
ether, C4H7(C2H5)02, which possesses a distinct pineapple flavor, and 
is prepared by mixing loo parts of butyric acid (C^HsOj), loo parts of 
alcohol, and 50 parts of sulphuric acid, and shaking. Butyric ether is 
sparingly soluble in water, and boils at 121° C. 

Artificial Quince Essence depends as a basis on ethyl pelargonate, 
sometimes called pelargonic or oenanthic ether, C2H5,C9Hi702, dissolved 
in alcohol. Pelargonic ether is formed by digestion with the aid of heat 
of pelargonic acid and alcohol. Pelargonic acid, CaH,g02, is first obtained 
by the action of nitric acid on oil of rue. Pelargonic ether is a colorless 
liquid, having a specific gravity of 0.8635 ^t 17.5° C. Its boiling-point 
is 227° to 228° C. It is insoluble in water. 

Artificial Jargonelle Pear Essence consists of an alcoholic solution 
of amyl or pentyl acetate, C5H„,C2H302. This is prepared by distilling 
a mixture of one part of amyl alcohol, two parts of potassium acetate, 
and one part of concentrated sulphuric acid. It is a colorless liquid, 
insoluble in water, and having a boiling-point of 137° C. 

Artificial Banana Essence is made up of a mixture of amyl acetate 
and butyric ether. 

Artificial Apple Essence is composed of an alcoholic solution of amyl 
valerianate, sometimes called apple oil, CsHi^CsHjOj, prepared by mixing 
four parts of amyl alcohol with four of sulphuric acid, and adding 
the mixture when cold to five parts of valerianic acid. The specific 
gravity of amyl valerianate is 0.879 ^^ 0° C. and its boiling-point is 188° C. 

The following table, prepared by Kletzinsky, shows the composition 



CANNED AND BOTTLED VEGETABLES, ETC 



753 



of a large variety of these artificial essences. The numerals in the various 
columns indicate the parts by volume to be added to one hundred parts 
of deodorized alcohol. 





i 

1 




V 

< 




u C 

11 




II 




o 


— 


rtJ= 

1" 


ill 


Pineapple 


I 




I 

2 
..... 

I 
2 
2 
2 






5 

4 

S 

I 


5 








lO 




5 
5 
5 

I 
S 
5 

lO 
lO 

5 
5 


I 
I 
I 




Strawberry 




I 
I 








I 








I 
I 


I 

I 

lO 





I 












2 
I 
2 


I 


2 
I 








Apple 


I 




I 

5 
S 








Orange 


I 


Pear 


I 


2 

4 

s 


I 




Lemon 

Black cherrv. . . 


I 


I 


2 




Cherry 
















Plum 






S 


I 


2 
10 

5 






Apricot 


I 




5 
S 




I 




Peach 




2 

I 


S 

5 


5 




Currant. 






I 


I 





















'o 

< 
■?. 

1 


o 




o 

•a 

^ ^^ 


O 


M 

S 
o 

O 


Saturated AlchoHc 
Solutions of 








S-6 

rt'u 


o 




•c 

5 


Pineapple 






lO 














3 
3 


Melon 
























3 

I 


2 

I 










.. 






Raspberry 










5 
5 
5 


I 


I 
I 

3 


I 


4 












Grape 
















Apple 








lO 






4 






I 

2 






lO 


I 






Pear 


























ID 




lO 


I 


I 


2 

I 


5 


Black cherry 










Cherry 
















3 
8 


Plum 




















Apricot 


2 

2 




I 








I 








4 

S 


Peach 














Currant 












5 





I 


I 



















754 FOOD INSPECTION AND ANALYSIS. 



REFERENCES ON CANNED FOODS, FRUIT PRODUCTS, AND 
FLAVORING EXTRACTS. 

Adams, M. A. Composition and Adulteration of Fruit Jams. Analyst, 9, 1884, p. 100. 
Angell, a. Microscopical Structure of Fruits, etc., to be met with in Jams and Pre- 
serves. Analyst, i, 1877, p. 73. 
BlOLETTi, F. T., and dai, Piaz, A. M. Preser\-ation of Unfermented Grape Must. Cal. 

E-xp. Sta. Bui. 130. 
BODMER, R., and MoOR, C. G. On Copper in Peas. Analyst, 22, 1897, p. 141. 
BosELEY, L. R. The Analysis of Marmalade. Analyst, 23, i8g8, p. 123. 
Browne, C. A. A Chemical Study of the Apple and Its Products. Pcnn. Dept. of 

Agriculture Bui. 58. 
Budden, E. R., and Hardy, H. Colorimctric Estimation of Lead, Copper, Tin, and 

Iron. Analyst, 19, 1894, 168. 
DoREMUS, C. A. Collecting and Analyzing Gases in Canned Goods. Jour. Am. 

Chem. Soc, 19, 733. 
Hausner, A. The Manufacture of Preserved Foods and Sweetmeats. London, 1902. 
Hess, W. H. The Distinction of True Extract of Vanilla from Liquid Preparations 

of Vanillin. Jour. Am. Chem. Soc, 21, 1899, p. 719. 
Hess, W. H., and Prescott, A. B. Coumarin and Vanillin, their Separation, Estima- 
tion and Identification in Commercial Flavoring Extracts. Jour. Am. Chem. 

Soc, 21, 1899, p. 256. 
Hilgard, E. W., and Colby, G. E. Investigations of Canned Products. Rep. Cal. 

Exp. Sta., 1897-98, p. 159. 
Hilgar, a., u. Laband, L. Ueber electrolytische Abscheidung von Kupfer, Zink und 

Zinn aus Konserven. Zeits. f. Unters. der Nahr. u. Genuss., 2, 795. 
Husmann, G. C. Manufacture and Preservation of Unfermented Grape Must. U. S. 

Dept. of Agric, Bur. of Plant Ind., Bui. 24. 
Ladd, E. F. Food Products and their Adulteration. (Canned Goods, Ketchups, 

Jellies, Jams and Extracts.) North Dak. Exp. Sta., Buls. 53 and 57. 
Macfarlane, T. Unfermented Grape Juice. Can. Inl. Rev. Dept. Bui. 82. 
McElroy, K. p., and Bigelow, W. D. Canned Vegetables. U. S. Dept. of Agric. 

Div. of Chem., Bui. 13, part 8. 
McGiLL, A. Canned Meats. Can. Inl. Rev. Dept. Bui. 85. 

Canned Vegetables. Can. Inl. Rev. Dept. Bui. 87. 

Lime Juice and Catsup. Can. Inl. Rev. Dept. Bui. 83. 

Mitchell, A. S. Lemon Flavoring Extract and its Substitutes. Jour. Am. Chem. 
Soc, 21, 1899, p. 1132. 

Flavoring Extracts. U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 69. 

MuNSON, L. S. Canned Vegetables. U. S. Dept. of Agric. Bur. of Chem., Bui. 56, 

P- 5°- 
MuNSON, L. S , and Tolman, L. M. Fruits and Fruit Products. U. S. Dept. of 

Agric, Bur. of Chem., Bui. 65, p. 74. 
MuNSON, L. S., Tolman, L. M., and Howard, B. J. Fruits and Fruit Products. 
U. S. Dept. of Agric, Bur. of Chem., Bui. 66. 



CANNED AND BOTTLED VEGETABLES. ETC. 755 

Prescott, S. C, and Underwood, W. S. Micro-organisms and Sterilizing Processes 

in the Canning Industry. Tech. Quarterly, lo, 1897, p. 183; also 11, 1898, p. 6. 
Spaeth, E. On Fruit Juices and their Examination, with Particular Reference to 

Raspberry Juice. Zeits. f. Unters. der Nahr. u. Genuss., 2, 1899, p. 633; Abs. 

Analyst, 25, 1900, p. 10. 
ToLMAN, L. M. The Polarization of Fruits, Jellies, Jams and Honies. Jour. Am. 

Chem. Soc, 24, 1902, 515. 
ToLMAN, L. M., Mltnson, L. S., and Bigelow, W. D. The Composition of Jellies 

and Jams. Jour. Am. Chem. Soc, 23, 1901, p. 347. 
Traphagen, F. W., and Burke, E. Occurrence of Salicylic Acid in Fruits. Jour. 

Am. Chem. Soc, 25, 1903, p. 242. 
Wilson, H. M. Adulteration of Tinned Peas by Copper. Pub. Health, Apr., 1892, 

p. 203. 
WiNTON, A. L. Detection of Coal Tar Dyes in Fruit Products. Jour. Am. Chem. Soc. 

22, 1900, p. 582. 
Beitriige zur Anatomie des Beerenobstes. Zeits. f. Unters. der Nahr. u. Genuss., 

5, 1902, p. 785. 
WiNTON, A. L., and Silverman, M. The Analysis of Vanilla E.xtract. Jour. Am. 

Chem. Soc, 24, 1902, p. 1129. 
Withers, W. A., and Primrose, H. W. Preser\'atives in Canned Foods in North 

Carolina. North Car. Exp. Sta. Bui. 165. 



APPENDIX. 

THE ZEISS IMMERSION REFRACTOMETER. 

Several forms of refractometer have heretofore been described, all 
of which have been of main use in connection with the study of oils and 
fats. A more recently devised instrument, the immersion refractometer, 
made by Zeiss, has many features that especially commend it to the use 
of the food analyst. The construction of the immersion refractometer 
is such that, as its name implies, it may be immersed directly in an almost 
endless variety of solutions, the strength of which, within limits, may 
be determined by the degree of refraction read upon an arbitrary scale. 
Thus, for example, the strengths of various acids and of a variety of 
salt solutions used as reagents in the laboratory, as well as of formaldehyde, 
of sugars in solution, and of alcohol, are all capable of determination by 
the use of the immersion refractometer. 

Figure 120 shows the form used by the viTiter. P is a glass prism 
fixed in the lower end of the tube of the instrument, while at the top of 
the tube is the ocular Oc, and just below this on a level with the vernier 
screw Z is the scale on which is read the degree of refraction of the liquid 
in which the prism P is immersed. The tube may be held in the hand 
and directly dipped in the liquid to be tested, this liquid being contained 
in a vessel with a translucent bottom, through which the light is reflected. 
The preferable method of use is, however, that shown in the cut. 

4 is a metal bath with inlet and outlet tubes, arranged whereby water 
is kept at a constant level. The water is maintained at a constant tem- 
perature by means of a controller of the same type as the refractometer 
heater shown in Fig. 92. In the bath A are immersed a number of 
beakers, containing the solutions to be tested. T is a frame on which is 
hung the refractometer by means of the hook H, at just the right height 
to permit of the immersion of the prism P in the liquid in any of the 
beakers in the row beneath. Under this row of beakers the bottom of 
the tank is composed of a strip of ground glass, through which light is 
reflected by an adjustable pivoted mirror. 

7S7 



7S8 



APPENDIX. 



The temperature of the bath is noted by a delicate thermometer 
immersed therein, capable of reading to tenths of a degree. 

Returning to the main refractometer-tube, R is a. graduated ring or 
collar which is connected by a sleeve within the tube with a compound 
prism near the bottom, the construction being such that by turning 
the collar R one way or the other the chromatic aberration or dispersion of 
any liquid may be compensated for, and a clear-cut shadow or critical line 
projected cross the scale. By the graduation on the collar R, the degree of 




Fig. 1 20. — The Zeiss Immersion Refractometer. 

dispersion may be read. Tenths of a degree on the main scale of the in- 
strument may be read with great accuracy by means of the vernier screw Z, 
graduated along its circumference, the screw being turned in each case till 
the critical line on the scale coincides with the nearest whole number. 

The scale of the instrument reads from — 5 to 105, corresponding 
to indices of refraction of from' 1.32539 to 1.36640. It should be noted 
tb?t the index of refraction may be read with a greater degree of accuracy 
on the immersion refractometer than on the Abbe instrument. 



THE ZEISS IMMERSION REFRACTOMETER. 



759 



TABLE OF INDICES OF REFRACTION, 



(Com 


jared with Scale 


headings 


f Zeiss 


mmersion 


Refractometer, according 


Wagner.) 


Scale 




Scale 




Scale 




Scale 




Scale 




Read- 


"d- 


Read- 


"o- 


Read- 


"D- 


Read- 


«Z)- 


Read- 


"d- 


ing. 




ing. 




ing. 




ing. 




ing. 




o.o 


1-327360 


5-0 


1.329320 


10.0 


I. 331260 


15.0 


1-333200 


20.0 


1. 335 1 68 


O. I 


I -327309 


S-i 


1-32935° 


10. I 


1-331299 


I5-I 


1-333238 


20. I 


I -335 1 68 


2 


438 


2 


398 


2 


388 


2 


276 


2 


206 


3 


477 


3 


437 


3 


377 


3 


314 


3 


244 


4 


S16 


4 


476 


4 


416 


4 


352 


4 


282 


S 


555 


5 


515 


■; 


455 


5 


390 


5 


320 


6 


594 


6 


554 


6 


494 


6 


428 


6 


358 


7 


633 


7 


593 


7 


533 


7 


466 


7 


396 


8 


672 


8 


632 


8 


572 


8 


504 


8 


434 


9 


711 


9 


671 


9 


611 


9 


542 


9 


472 


I.O 


750 


6.0 


710 


II. 


650 


16.0 


580 


21 .0 


510 


I.I 


1.327789 


6.1 


1-329749 


II . I 


1.331689 


16. 1 


I -333619 


21 . 1 


1-335549 


2 


828 


2 


788 


2 


728 


2 


658 


2 


S88 


3 


867 


3 


827 


3 


767 


3 


697 


3 


627 


4 


qo6 


4 


866 


4 


806 


4 


736 


4 


666 


5 


945 


5 


905 


5 


845 


5 


775 


■; 


705 


6 


984 


6 


944 


6 


884 


6 


814 


6 


744 


7 


t. 328023 


7 


982 


7 


932 


7 


833 


7 


783 


8 


062 


8 


1.330022 


8 


962 


8 


892 


8 


822 


9 


lOI 


9 


061 


9 


I. 332001 


9 


931 


9 


861 


2.0 


140 


7-0 


100 


12.0 


040 


17.0 


970 


22.0 


900 


2. I 


1.3281S0 


7-1 


1-330139 


12. 1 


1.332078 


17. 1 


I . 334008 


22. 1 


I - 335938 


2 


220 


2 


178 


2 


116 


2 


046 


2 


976 


3 


657 


3 


217 


3 


154 


3 


084 


3 


1-3,36014 


4 


300 


4 


256 


4 


192 


4 


122 


4 


052 


S 


340 


5 


295 


i; 


230 


5 


160 


5 


090 


6 


380 


6 


334 


6 


268 


6 


iq8 


6 


128 


7 


420 


7 


373 


7 


304 


7 


236 


7 


166 


8 


460 


8 


412 


8 


344 


8 


274 


8 


204 


9 


500 


9 


451 


9 


3S2 


9 


312 


9 


242 


3-° 


540 


8.0 


490 


13-0 


420 


18. c 


350 


23.0 


280 


3-1 


1.328579 


8.T 


1.330528 


13-1 


1-332459 


18,1 


1-334,389 


23-1 


I -336319 


2 


618 


2 


566 


2 


498 


2 


428 


2 


358 


3 


657 


3 


604 


3 


537 


3 


467 


3 


397 


4 


696 


4 


642 


4 


576 


4 


506 


4 


436 


5 


735 


5 


680 


5 


615 


5 


545 


5 


475 


6 


774 


6 


718 


6 


654 


6 


584 


6 


514 


7 


813 


7 


756 


7 


693 


7 


623 


7 


553 


8 


852 


8 


794 


8 


732 


8 


662 


8 


592 


9 


891 


9 


832 


9 


771 


9 


701 


9 


631 


4.0 


930 


9.0 


870 


14.0 


810 


19.0 


740 


24-0 


670 


41 


1.328969 


9.1 


I - 330909 


14. 1 


t. 332849 


19. 1 


1-334770 


24.1 


I . 336708 


2 


I . 329008 


2 


948 


2 


888 


2 


818 


2 


746 


3 


0-17 


3 


987 


3 


927 


3 


857 


3 


7S4 


4 


085 


4 


1. 331026 


4 


966 


4 


896 


. 4 


822 


5 


125 


5 


104 


5 


1-333005 


5 


935 


5 


860 


6 


164 


6 


104 


6 


044 


6 


974 


6 


8q8 


7 


203 


7 


143 


7 


083 


7 


I -335013 


7 


036 


8 


242 


8 


182 


8 


122 


8 


052 


8 


974 


9 


281 


9 


221 


9 


161 


9 


ogi 


9 


1.337012 


5° 


320 


10. 


260 


iS-o 


200 


20.0 


130 


25.0 


050 



760 








APPENDIX. 












TABLE OF INDICES OF REFRACTION, 


tijy — {Continued). 




Scale 




Scale 




Scale 




Scale 




Scale 




Read- 


«£>• 


Read- 


«ij- 


Read- 


«D- 


Read- 


»Z)- 


Read- 


nD. 


ing. 




ing. 




ing. 




ing. 




ing. 




25.0 


I- 337050 


30.0 


I . 338960 


3S-0 


1 . 340860 


40.0 


1-342750 


45-0 


I . 344630 


25-1 


1.337088 


30.1 


1-338998 


.35-1 


1.340898 


40. I 


1.342788 


45-1 


I . 344667 


2 


126 


2 


1-339036 


2 


936 


2 


826 


2 


704 


3 


164 


3 


074 


3 


974 


3 


864 


3 


741 


4 


202 


4 


112 


4 


1.341012 


4 


902 


4 


778 


5 


240 


5 


ISO 


5 


o(;o 


5 


940 


5 


818 


6 


278 


6 


188 


6 


088 


6 


978 


6 


852 


7 


316 


7 


226 


7 


126 


7 


I. 34301 6 


7 


889 


8 


354 


8 


264 


8 


164 


8 


054 


8 


926 


9 


392 


9 


302 


9 


202 


9 


092 


9 


963 


26.0 


430 


31.0 


340 


36.0 


240 


41.0 


130 


46.0 


1.345000 


26.1 


1-337468 


31-1 


1-339378 


36.1 


I. 341278 


41. 1 


t -343167 


46. 1 


1-345037 


2 


506 


2 


416 


2 


316 


2 


204 


2 


074 


3 


544 


3 


454 


3 


354 


3 


241 


3 


III 


4 


582 


4 


492 


4 


.392 


4 


278 


4 


148 


S 


620 


5 


530 


5 


430 


5 


315 


5 


185 


6 


658 


6 


S68 


6 


468 


6 


352 


6 


222 


7 


696 


7 


606 


7 


506 


7 


389 


7 


259 


8 


734 


8 


644 


8 


544 


8 


426 


8 


296 


9 


772 


9 


682 


9 


582 


9 


463 


9 


333 


27.0 


810 


32.0 


720 


37-0 


620 


42.0 


500 


47.0 


370 


27.1 


1-337849 


32.1 


I -.339758 


37-1 


I -341657 


42.1 


1-343538 


47-1 


1.345408 


2 


888 


2 


796 


2 


694 


2 


576 


2 


446 


3 


927 


3 


834 


3 


731 


3 


614 


3 


484 


4 


966 


4 


872 


4 


768 


4 


652 


4 


522 


S 


1-338005 


5 


910 


S 


80s 


5 


690 


5 


560 


6 


044 


6 


948 


6 


842 


6 


728 


6 


598 


7 


083 


7 


986 


7 


879 


7 


766 


7 


636 


8 


122 


8 


1.340024 


8 


916 


8 


804 


8 


674 


9 


161 


9 


062 


9 


953 


9 


842 


9 


712 


28.0 


200 


33-0 


100 


38.0 


99° 


43-0 


880 


48. 


750 


28.1 


1-338238 


33-1 


I . •^40138 


38.1 


I . 342028 


43-1 


1-343918 


48.1 


1-345787 


2 


276 


2 


176 


2 


066 


2 


956 


2 


824 


3 


314 


3 


214 


3 


104 


3 


994 


3 


861 


4 


352 


4 


252 


4 


142 


4 


1-344032 


4 


898 


S 


390 


5 


290 


5 


180 


5 


070 


5 


935 


6 


428 


6 


328 


6 


218 


6 


108 


6 


972 


7 


466 


7 


366 


7 


256 


7 


146 


7 


1 . 346009 


8 


5°4 


8 


404 


8 


294 


8 


184 


8 


046 


9 


542 


9 


442 


9 


332 


9 


222 


9 


083 


29.0 


580 


34-0 


480 


.39-0 


370 


44.0 


260 


49.0 


120 


2C1.I 


I. 338618 


34-1 


I. 340518 


.39-1 


r. 342408 


-14 -I 


1.344297 


49-1 


I. 346158 


2 


656 


2 


■556 


2 


446 


2 


334 


2 


iq6 


3 


694 


3 


594 


3 


484 


3 


371 


3 


234 


4 


732 


4 


632 


4 


522 


4 


408 


4 


272 


5 


770 


5 


670 


5 


560 


5 


445 


5 


310 


6 


808 


6 


708 


6 


598 


6 


482 


6 


348 


7 


846 


7 


746 


7 


636 


7 


519 


7 


386 


8 


884 


8 


784 


8 


674 


8 


556 


8 


424 


9 


922 


9 822 


9 


712 


9 


593 


9 


462 


30.0 


960 


35.0 860 


40.0 


750 


45-0 


630 


50.0 


500 



THE ZEISS IMMERSION REFRACTOMETER 



761 





TABLE OF INDICES OF REFRACTION, 


H^ — {Continued}. 




Scale 




Scale 




Scale 




Scale 




Scale 




Read- 


«£,. 


Read- 


»/?• 


Read- 


»£)■ 


Read- 


»Z)- 


Read- 


«£)• 


ing. 




ing. 




ing. 




ing. 




ing. 




50.0 


1.346500 


55 -o 


1.348360 


60.0 


I. 350210 


65.0 


1-352050 


70.0 


1-353880 


50.1 


1-346537 


55-1 


1-348397 


60.1 


1.350247 


65-1 


1.352087 


70.1 


I-353917 


2 


574 


2 


434 


2 


284 


2 


124 


2 


954 


3 


611 


3 


471 


3 


321 


3 


161 


3 


991 


4 


648 


4 


508 


4 


35S 


4 


198 


4 


1.354028 


5 


685 


5 


545 


5 


395 


5 


235 


5 


065 


6 


722 


6 


582 


6 


432 


6 


272 


6 


102 


7 


759 


7 


619 


7 


469 


7 


309 


7 


139 


8 


796 


8 


656 


8 


506 


8 


346 


8 


176 


9 


833 


9 


693 


9 


543 


9 


383 


9 


213 


51-° 


870 


56.0 


730 


61.0 


580 


66.0 


420 


71.0 


250 


Si-i 


I . 346907 


56.1 


1.348767 


61. 1 


I. 35061 7 


66.1 


1-352457 


71. 1 


1.354286 


2 


944 


2 


804 


2 


654 


2 


494 


2 


322 


3 


981 


3 


841 


3 


691 


3 


531 


3 


358 


4 


I. 347018 


4 


878 


4 


728 


4 


568 


4 


394 


5 


055 


5 


915 


S 


765 


5 


60s 


5 


430 


6 


092 


6 


952 


6 


802 


6 


642 


6 


466 


7 


129 


7 


989 


7 


839 


7 


679 


7 


502 


8 


166 


8 


1.349026 


8 


876 


8 


716 


8 


538 


9 


203 


9 


063 


9 


913 


9 


753 


9 


574 


52-0 


240 


57-0 


100 


62.0 


95° 


67.0 


790 


72.0 


610 


52-1 


1-347277 


57-1 


1-349137 


62.1 


1-350987 


67.1 


1.352827 


72.1 


1-354646 


2 


314 


2 


174 


2 


I. 351024 


2 


864 


2 


682 


3 


351 


3 


211 


3 


061 


3 


901 


3 


718 


4 


388 


4 


248 


4 


098 


4 


938 


4 


754 


S 


425 


5 


285 


5 


135 


5 


975 


5 


790 


6 


462 


6 


312 


6 


172 


6 


I -353012 


6 


826 


7 


499 


7 


359 


7 


20g 


7 


049 


7 


862 


8 


536 


8 


396 


8 


246 


8 


086 


8 


898 


9 


573 


9 


433 


9 


283 


9 


123 


9 


934 


S3-0 


610 


58.0 


470 


63.0 


320 


68.0 


160 


73-0 


970 


S3-I 


1-347647 


58.1 


1-349507 


63.1 


1-351357 


68.1 


1-353196 


73-1 


I -355006 


2 


684 


2 


544 


2 


394 


2 


232 


2 


042 


3 


721 


3 


581 


3 


431 


3 


268 


3 


078 


4 


758 


4 


618 


4 


468 


4 


304 


4 


114 


5 


795 


5 


655 


5 


505 


5 


340 


5 


150 


6 


832 


6 


692 


6 


542 


6 


376 


6 


186 


7 


869 


7 


729 


7 


579 


7 


412 


7 


222 


8 


906 


8 


766 


8 


616 


8 


448 


8 


258 


9 


943 


9 


803 


9 


653 


9 


484 


9 


294 


S4-0 


980 


59-0 


840 


64.0 


690 


69.0 


520 


74.0 


330 


54. 1 


I. 348018 


59-1 


1-349877 


64.1 


1. 351726 


69. 1 


1-353556 


74-1 


1-355366 


2 


056 


2 


914 


2 


762 


2 


592 


2 


402 


3 


094 


3 


951 


3 


798 


3 


628 


3 


438 


4 


132 


4 


988 


4 


834 


4 


664 


4 


47+ 


5 


170 


5 


1.350025 


5 


870 


5 


700 


5 


510 


6 


208 


6 


062 


6 


906 


6 


736 


6 


546 


7 


246 


7 


099 


7 


942 


7 


772 


7 


582 


8 


284 


8 


136 


8 


97S 


8 


80S 


8 


618 


9 


322 


9 


173 


9 


1.352014 


9 


844 


9 


659 


55 -o 


360 


60.0 


210 


65.0 


050 


70.0 


8S0 


75-° 


690 



762 



APPENDIX. 





TABLE OF INDICES OF REFRACTION, 


n^ — {Continued). 




Scale 




Scale 




Scale 




Scale 




Scale 




Read- 


"D- 


Read- 


"d- 


Read- 


"D- 


Read- 


»D- 


Read- 


"d- 


ing. 




ing. 




ing. 




ing. 




ing. 




75-° 


'■355690 


80.0 


1-357500 


85.0 


1-359300 


90.0 


I .361090 


95-0 


T .362S70 


75-1 


1-355727 


80.1 


1-357536 


85.1 


1-359336 


90.1 


T . 361 1 26 


95-1 


I . 362006 


2 


764 


2 


572 


2 


372 


2 


162 


2 


942 


3 


801 


3 


608 


3 


408 


3 


198 


3 


978 


A 


838 


4 


644 


4 


444 


4 


234 


4 


I. 363014 


5 


875 


5 


680 


5 


480 


5 


270 


5 


050 


6 


912 


6 


716 


6 


516 


6 


306 


6 


086 


7 


949 


7 


752 


7 


552 


1 


342 


7 


122 


8 


986 


8 


788 


8 


588 


8 


378 


8 


158 


9 


1.356023 


9 


824 


9 


624 


9 


414 


9 


194 


76.0 


060 


81.0 


860 


86.0 


660 


91.0 


450 


96.0 


230 


76.1 


1.356096 


81. 1 


1-357896 


86.1 


1.359696 


91. 1 


I. 361486 


96. 1 


1.363256 


2 


132 


2 


932 


2 


732 


2 


522 


2 


292 


3 


168 


3 


968 


3 


768 


3 


558 


3 


328 


4 


204 


4 


I . 358004 


4 


804 


4 


594 


4 


364 


5 


240 


5 


040 


5 


840 


5 


630 


5 


400 


6 


276 


6 


076 


6 


876 


6 


666 


6 


436 


7 


312 


7 


112 


7 


912 


7 


702 


7 


472 


8 


348 


8 


148 


8 


948 


8 


738 


8 


518 


9 


384 


9 


184 


9 


984 


9 


774 


9 


554 


77.0 


420 


82.0 


220 


87.0 


I . 360020 


92.0 


810 


97-0 


590 


77-1 


1-356456 


82.1 


1.358256 


87.1 


1.360056 


92.1 


I 361846 


97-1 


1.363625 


2 


492 


2 


292 


2 


092 


2 


882 


2 


660 


3 


528 


3 


328 


3 


128 


3 


918 


3 


695 


4 


564 


4 


364 


4 


164 


4 


954 


4 


730 


5 


600 


5 


400 


5 


200 


s 


990 


5 


765 


6 


636 


6 


436 


6 


236 


6 


1.362026 


6 


800 


7 


672 


7 


472 


7 


272 


7 


062 


7 


835 


8 


708 


8 


S08 


8 


308 


8 


098 


8 


870 


9 


744 


9 


544 


9 


344 


9 


134 


9 


90s 


78.0 


780 


83.0 


580 


88.0 


380 


93-0 


170 


98.0 


940 


78.1 


I. 356816 


83-1 


I. 358616 


88.1 


I. 36041 6 


93-1 


1.362205 


98.1 


1-363975 


2 


852 


2 


652 


2 


452 


2 


240 


2 


I. 364010 


3 


888 


3 


688 


3 


488 


3 


27s 


3 


045 


4 


924 


4 


724 


4 


524 


4 


310 


4 


080 


s 


960 


5 


760 


5 


560 


5 


345 


5 


"5 


6 


996 


6 


796 


6 


596 


6 


380 


6 


160 


7 


I •357032 


7 


832 


7 


632 


7 


415 


7 


195 


8 


068 


8 


858 


8 


668 


8 


450 


8 


230 


9 


104 


9 


904 


9 


704 


9 


485 


9 


265 


79.0 


140 


84.0 


940 


89.0 


740 


94-0 


520 


99-0 


290 


79.1 


1-357176 


84.1 


1.358976 


89.1 


1-360775 


94-1 


I 362555 


99-1 


1-364325 


2 


212 


2 


I. 359012 


2 


810 


2 


590 


2 


360 


3 


248 


3 


048 


3 


845 


3 


625 


3 


395 


4 


284 


4 


0S4 


4 


880 


4 


660 


4 


430 


5 


320 


5 


120 


5 


915 


5 


695 


5 


465 


6 


356 


6 


156 


6 


950 


6 


730 


6 


500 


7 


392 


7 


192 


7 


985 


7 


765 


7 


535 


8 


428 


8 


228 


8 


I. 361020 


8 


800 


8 


570 


g 


464 


9 


264 


9 


055 


9 


835 


9 


605 


80.0 


500 


85.0 


300 


90.0 


090 


95-0 


870 


100. 


640 



THE ZEISS IMMERSION REFRACTOMETER. 



763 



SCALE READING AND INDEX OF REFRACTION OF DISTILLED WATER 
AT 10-30° C, ACCORDING TO WAGNER. 



Temper- 


Scale 


Index of 


nj) Differ- 


Temper- 


Scale 


Index of 


Hj) Differ- 


ature C. 


Reading. 


Refraction, «^. 


ence for 


ature C. 


Reading. 


Refraction, «^^ 


ence for 








i°C. 






i°C. 


30 


II. 8 


1-33196 




19 


14-7 


1-33,^075 


8-5 


29 


12 


I 




33208 


12.0 


18 


14.9 




33316 


8-5 


28 


12 


4 




332195 


II-5 


I7-S 


15-0 




33320 


n- 


27 


12 


7 




3i'i^ 


"•5 


17 


15-I 




33324 


26 


13 







33242 


II .0 


16 


iS-3 




333315 


7-5 


25 


13 


25 




332525 


10.5 


15 


15-5 




33339 


7-5 


24 


13 


5 




332625 


10. 


14 


15-7 




33346 


7.0 


23 


13 


75 




33272 


9-5 


13 


15-85 




333525 


6-5 


22 


14 







33281 


9-0 


12 


16.0 




33359 


6-5 


21 


14 


25 




33290 


9.0 


II 


16. 15 




33365 


6.0 


20 


14-5 


1-33299 


9.0 


10 


16.3 




333705 


5-5 



SCALE READINGS AT TEMPERATURES FROM 10-30° C. 
Corrected to 17.5°, According to Wagner. 



No. 


- 


2. 


3. 


4- 


s. 


6. 


7. 


8. 


9- 


10. 


II. 


12 & 13. 


No. 












Scale Readi 


ng at 


■7.5° c 










So 


|2 


15. 


20. 


25. 


30. 


33- 


40. 


45. 


so. 


60. 


70. 


80. 


go & 100. 




30 


+ 3-20 


3-15 


3-25 


3-40 


3-55 


3-65 


3-9° 


4-05 


4.20 


4.60 


4.80 


5-25 


30 


29 
28 

27 
26 


2.90 
2.60 

2.30 
2.00 


2.85 

2-55 
2.25 

1-95 


2-95 
2.65 

2-35 
2.05 


3-1° 
2.80 
2.50 
2.20 


3-25 
2-95 
2-65 
2-35 


3-35 
3-05 
2-75 
2.45 


3-55 
3-25 
2-95 
2-55 


3-75 
3-45 
3-15 
2.80 


390 
3-60 
3-30 

2-95 


4.2S 
3 90 
3-5° 
3-10 


4-45 
4-10 

3-75 
3-3° 


4-85 
4-50 
4. 10 
3-65 


29 

28 

27 
26 


25 


1-75 


1-75 


1.80 


1.90 


2-05 


2.15 


2.25 


2-45 


2.60 


2.70 


2-95 


3.20 


25 


24 
23 
22 

21 


1.50 

1-25 
1. 00 

0.75 


1-45 
1-25 
1 .00 

0-75 


1-55 
1.30 

1-05 
0.80 


1.60 

1-35 
1 . 10 
0.85 


1-75 
1-45 
1-15 
0.90 


1. 8s 

1-55 
1-25 
0-95 


1-95 
1. 6s 
1.30 

i-°5 


2.10 

1-75 
1 .40 

1-05 


2.25 
1 .90 

1-55 
1.20 


2-35 
2.00 
1.65 
1-25 


2-55 
2-15 
1-75 
1-35 


2-75 
2-35 
I. go 

1-45 


24 

23 
22 
21 


20 


0.50 


0.50 


0-55 


0.60 


0.65 


0.65 


0-75 


0-75 


0.85 


0.90 


0-95 


1-05 


20 


19 
18 


0.30 
0. 10 


0.30 

O.IO 


Q.30 
0. 10 


0.35 
0.15 


0.40 
0.15 


0.40 
°-i5 


0-45 
0-15 


0-45 
o-iS 


0.45 
0-15 


0-55 
0.20 


0-55 
0.20 


0.60 
0.20 


19 
18 


17-5 


0.00 


0.00 


0.00 


0,00 


0.00 


0.00 


0.00 


0.00 


0.00 


0.00 


0.00 


0.00 


17-5 


17 
16 


— O.IO 

0.30 


O.IO 

0.30 


0. 10 
0.30 


0. 10 
0.30 


0. 10 
0-35 


0. 10 
0-35 


0-15 
0.40 


0.15 
0.45 


°-i5 
0.45 


0.15 
°-5o 


0.20 
°-55 


0.20 
0-55 


17 
16 


15 


0.50 


0.45 


0.45 


0.50 


0.60 


0.60 


0.65 


0.75 


0-75 


0.80 


0.85 


0.90 


15 


14 
13 
12 


0.70 
0.85 
1. 00 
1-15 


0.60 

0.75 


0.60 
0.75 


0.70 
0.85 


0.80 
1. 00 


0.8s 
1. 10 


0.90 
1-15 


0.95 
1.20 


I. OS 
1-35 


1 .10 
1.40 


1-25 
1-55 


1-25 
1.60 


14 
13 


II 




















































10 


1-25 




















































No. 


I. 


3. 


3. 


4- 


s. 


6.' 


7. 


8. 


9- 


10. 


II. 


12 & 13. 


No. 



764 



yfPPENDIX. 



Adjustment of the Ocular Scale. — ^The instrument is so adjusted that 
the critical line for distilled water at the temperature of 17.5° C. has a 
scale reading of exactly 15, corresponding to an index of refraction of 
1-33320. 

STRENGTHS OF VARIOUS SOLUTIONS. — The most extensive work on the 
quantitative determination of the strength of a large number of common 
aqueous solutions with the immersion refractometer has been done by 
Wagner, who has published a large number of tables. These tables 
show the percentage strength (grams per 100 cc. at 17.5° C.) of a large 
number of salt solutions and of acids, corresponding to the range of scale 
readings of the instrument, as well as of cane sugar, dextrose, formalde- 
hyde, alcohol, etc. All these observations have been based on the Mohr 
liter, at a temperature of 17.5°. More convenient for the American 
analyst would be tables based on the use of a higher temperature, say 

SCALE READINGS ON IMMERSION REFRACTOMETER OF VARIOUS STAND- 
ARD REAGENTS USED IN VOLUMETRIC ANALYSIS * 



Temperature C. 



15°. 16°. 17°. 17.5°. 18°. 19°. 20°. 21°. 22' 



Hydrochloric acid: 

Normal 

Tenth-normal 

Sulphuric acid: 

Normal 

Fifth-normal 

Tenth-normal 

Oxalic acid: 

Half-normal. 

Tenth-normal 

Potassium bitartrate: 

Tenth-normal 

Potassium hydroxide: 

Normal 

Tenth-normal 

Sodium hydroxide: 

Tenth-normal 

Sodium thiosulphate; 

Tenth-normal 

Potassium bichromate: 

Tenth-norma I 

Silver nitrate: 

Tenth-normal 

Sodium chloride; 

Tenth-normal 

Ammonium sulphocyanate : 

Tenth-normal 



37-45 
17.80 

30.60 
is. 75 
17-15 

22.45 
17-15 

17-75 

43-9° 
18.45 

18.50 

24. 20 

17-75 
20.20 
18.20 
20.60 



17-55 



36.95 
17.40 

30.20 
18.40 
16-75 

22. 10 
16.75 

17-35 

43.40 
18.10 

18.15 
23.85 
17.35 
19.85 
17.80 
20.25 



17-25 



36.70 
17.20 

29 -95 
18.20 

16.55 

21.90 
16.55 

17-15 

43.10 
17.90 

17-95 
23-65 
17-15 
19.65 
17.60 
20.05 



36.45 
17.00 

29.75 
18.00 
16.35 

21.70 
16.35 

16.95 

42.80 
17.70 

17-75 
23-45 
16.95 

19.45 
17.40 
19.85 



16.75 



35-95 
16.55 

29.25 
17.55 
15.90 

21.25 
15.90 

16.50 

42.20 

17.25 

17.30 
22.95 
16.50 
19.00 
16.95 
19.40 



35.70 
16.30 

29.00 
17.30 
15.65 

21 .00 
15-65 

16.25 

41 -95 

17.00 

17-05 
22.70 
16.25 

18.7s 
16.70 

19-15 



* According to Wagner, all these solutions were made up at 17.5° C. Readings at different tem- 
peratures are given for convenience. 



THE ZEISS IMMERSION REFRACTOMETER. 



765 



20°, and the analyst is recommended to work out his own standards for 
comparison, at the temperature best suited to his special locality and 
convenience. The instrument is especially useful in preparing normal 
and tenth-normal solutions. 

The table on page 764, from Wagner, shows the strength of various 
common laboratory reagents. 

DETECTION OF ADDED WATER IN MiLK.— The addition of water to milk 
perceptibly affects the degree of refraction of its serum, to such an extent 
that added water may often be detected by means of the immersion 
refractometer. In curdling milk-samples for examination and com- 
parison by this method, care should be taken to observe absolutely identi- 
cal conditions in all cases. 



I. CONSTANTS OF MILK AND MILK SERUM. LABORATORY SAMPLES. 



Determinations on Milk, 


On Milk Serum. 


Total SoUds, 
Per Cent. 


Water, 
Per Cent. 


Fat, 
Per Cent. 


Solids 
not Fat, 
Per Cent. 


Ash, 
Per Cent. 


Specific 
Gravity 
at 15° C. 


Specific 
Gravity 
at 15° C. 


Immersion 
Refractom- 
eter Read- 
ing at 20° C. 


16.4s 
15.90 


83. =5 


8.2Q 


8.3C 




I ri'jcc 


1.0274 
I .0285 


AQ "^^ 


84 


10 


7 


00 


8 


90 


0.69 




— J J 
0277 


if-/ 

42 


00 


14 -37 


85 


63 


S 


50 


8 


88 


0.58 




0282 


1.0280 


42 


40 


14.17 


85 


83 


4 


85 


9 


32 


0.62 




0313 


I .0281 


44 


20 


14.04 


85 


96 


4 


95 


9 


09 


0.60 




0303 


1.0274 


42 


70 


13.80 


86 


20 


S 


00 


8 


80 


0.65 




0302 


I .0289 


42 


75 


13-59 


86 


41 


4 


30 


9 


29 


0.64 




0321 


I .0285 


44 


50 


13-39 


86 


61 


4 


40 


8 


99 


0.50 




0324 


1.0285 


43 


70 


13-28 


86 


72 


4 


40 


8 


88 


0.60 




0299 


I .0289 


42 


65 


13.12 


86 


88 


4 


00 


9 


12 


0-59 




0317 


I .0280 


43 


75 


13.00 


87 


00 


4 


30 


8 


70 


0.56 




0310 


I .0266 


42 


60 


12.90 


87 


10 


3 


85 


9 


°5 


0.61 




0318 


I . 0289 


43 


40 


12.80 


87 


20 


4 


30 


8 


50 


0.46 




0304 


1.0277 


42 


70 


12.70 


87 


30 


3 


80 


8 


90 


0-53 




0314 


I .0280 


43 


10 


12.63 


87 


37 


3 


5° 


9 


13 


0.65 




0323 


1.0277 


43 


65 


12.62 


87 


38 


4 


10 


8 


52 


0.52 




0298 


I .0272 


42 


40 


12-57 


87 


43 


3 


70 


8 


87 


0.68 




0317 


1.0278 


43 


45 


12.47 


87 


53 


3 


60 


8 


87 


0.65 




0303 


1.0282 


43 


15 


12.36 


87 


64 


3 


20 


9 


16 


0-55 




0327 


1.0282 


43 


25 


12.30 


87 


70 


3 


20 


9 


10 


0.62 




0327 


1.0283 


44 


00 


12. 16 


87 


84 


4 


35 


7 


81 


0.49 




027s 


1.0265 


41 


10 


12.00 


88 


00 


3 


40 


8 


60 


0.62 




0275 


1.0280 


41 


75 


11.86 


88 


14 


3 


60 


8 


26 


0.49 




0306 


I .0266 


42 


40 


11.67 


88 


ii 


3 


95 


7 


77 


0.48 




0265 


1.0240 


39 


3° 


11.60 


88 


40 


2 


75 


8 


85 


0.65 




0320 


I .0282 


43 


55 


11.50 


88 


50 


3 


45 


8 


05 


0.51 




0290 


1.0269 


41 


40 


11.40 


88 


60 


3 


10 


8 


3° 


0.60 




0297 


1.0278 


42 


00 


11.25 


88 


75 


2 


80 


8 


45 


0.58 




0280 


1.0274 


40 


90 


11.07 


88 


93 


3 


00 


8 


07 


0.62 




0290 


1.0270 


40 


75 


10.69 


89 

89 


31 

75 


2 


95 
20 


7 
6 


74 
95 






0288 


I . 0262 


39 
36 


85 
40 


10.25 


3 


0-55 




0230 


1.0223 


8-34 


91.66 


2 . 20 


6 


14 


0.38 




0224 


I .0207 


34 


70 



766 



APPENDIX. 



The method of curdling employed in the author's laboratory is that 
of Woodman (p. 129), using acetic acid, and Tables I-III show the varia- 
tion of specific gravity and immersion refractometer readings on milk of 
different composition, the refractometer readings being made at 20° C. 

The table on page 765 shows analyses of milk, selected from a 
wide range of samples regularly collected and examined in the routine 
of food inspection by the Massachusetts State Board of Health. 

The following table (II) shows analyses of a whole milk submitted 
by the author to varying degrees of watering, up to 50% of added water: 

II. CONSTANTS OF MILK AND MILK SERUM. A WHOLE MILK 
SYSTEMATICALLY WATERED. 



Determinations on Milk. 


On Milk Serum. 


Added 

Water, 

Per Cent. 


Total 

Solids, 

Per Cent. 


Water, 
Per Cent. 


Fat. 
Per Cent. 


SoHds 
not Fat, 
Per Cent. 


Ash, 
Per Cent. 


Specific 
Gravity 
at I 5° C. 


Specific 
Gravity 
at 15° C. 


Immersion 
Refrac- 
tometer 
Reading 
at 20° C. 



10 


12.65 
11-33 


87-35 
88.67 


4.00 
3-50 


8.65 
7-83 


0.65 
0.60 


1-0315 
I .0278 


I .0287 
I .0260 


42.40 
39-75 


20 


10. 10 


89.90 


3.10 


7.00 


0-53 


1.0252 


1.0230 


36.90 


30 


8-95 


91.05 


2.80 


6. IS 


0.48 


I. 02 1 1 


1 . 0200 


34-10 


40 


7.67 


92.33 


2.40 


5-27 


0.40 


I .0192 


I .0167 


31.10 


5° 


6-43 


93-57 


2.00 


4-43 


0.38 


1.0154 


I. 0140 


28.45 



Table III shows a centrifugally skimmed milk, systematically watered 
up to 50% of added water, as in Table II. It will be observed that 
both the specific gravity and immersion refractometer readings of the 
serum in Table II, agree very closely with those of tlie skimmed milk in 
Table III, in cases having a corresponding amount of added water. 

III. CONSTANTS OF MILK AND MILK SERL'M. A SKIMMED MILK 
SYSTEMATICALLY WATERED. 



Determinations on Milk. 


On Milk Serum. 


















Immersion 


Added 


Total 




Fat 


Solids 


Ash 


Specific 


Specific 


Refrac- 


Water, 


Solids, 


Per Cent 


Per Cent 


not Fat, 


Per Cent 


Gravity 


Gravity 


tometer 


Per Cent. 


Per Cent. 






Per Cent. 




at 15° C. 


at 15° C. 


Reading 
at 20° C. 





9-05 


90-95 


0.03 


9.02 


0.64 


1.0350 


I . 0296 


42.85 


10 


8.14 


91.85 


0.03 


8. II 


0.60 


1. 0317 


I .0260 


39.60 


20 


7.27 


92-73 


0.02 


7-25 


0.56 


1.0278 


I .0230 


36.85 


30 


6.41 


93-59 


0.02 


6-39 


0.4S 


1.0247 


I . 0200 


34-00 


40 


5-50 


94-50 


O.OI 


5-49 


0.44 


I .0209 


I .0170 


31.20 


50 


4.61 


95-39 


O.OI 


4.60 


0-39 


I .0172 


I. 0140 


28.50 



REFINED SUGAR IN MAPLE PRODUCTS. 767 

A comparison of the immersion refractometer readings of the serum 
of milk of varying quality shows at once that the refraction of the serum 
is a general index to watering. A reading below 40 with the above 
conditions carefully observed would be suspicious of added water, though 
39 might more safely be placed as a limit, below which milk could be 
declared fraudulently watered. 

REFERENCES ON THE IMMERSION REFRACTOMETER. 

AcKERMANN E. ET VON SpusTDLER, O. Sut la Determination de I'Extrait de la Biere. 

Jour. Suisse de Chim. et Pharm., 1903, No. 30. 
KiONKA, H. Ueber naturliche und kiinstliche Mineralwasser. Balneolog. Zeit., 14, 

Nos. 34 u. 35. 
Matthes, H. Quantitative Bestimmungen wasseriger Losunguen mit dem Zeiss'- 

schen Eintauch-Refraktometer. Zeits. fur Unters. der Nahr. u. Genuss., 1902, 

P- 1037- 

Ueber refraktometrische analytische Bestimmungsmethoden. Zeits fur anal. 

Chem., 13 (1904), Heft 2. 

Matthes, H., u. Mijller, F. Ueber die Untersuchung des Milchserums mit dem 
Zeiss'schen Eintauchrefraktometer. Zeits. fur ofFentl. Chem., 1903, p. 173. 

Wagner, B. Ueber quantitative Bestimmungen wasseriger Losungen mit dem Zeiss'- 
schen Eintauch-Refraktometer. Sondershausen, 1903. 



THE DETECTION OF REFINED CANE SUGAR IN MAPLE SUGAR 

AND SYRUP. 

Method of Julius Hortvet.* — This method depends on the principle 
that the volume of the precipitate, by treatment of the sugar solution or 
syrup under fi.xed conditions with alumina cream and subacetate of lead, 
varies with the amount of refined sugar present. 

Apparatus. — (i) A tube, adapted to be carried in the shield of the 
centrifuge. This tube, which is 15.3 cm. in length, has a wide cylindrical 
portion 3 cm. in diameter, narrowed at the top to a neck 2 cm. in diameter, 
and at the bottom to a stem graduated in tenths to 5 cc. 

(2) A holder, made of pine or white wood, of a size adapted to carry 
the tube in the shield of the centrifuge. The holders and tubes should 
be arranged in balanced pairs in the centrifuge. 

Procedure. — Introduce 5 cc. of syrup or 5 grams of sugar into the 
tube. Add 10 cc. of water, and dissolve completely. Next add 10 drops 

* Submitted for adoption among the food methods of the Association of Official Agricul- 
tural Chemists. 



768 



APPENDIX. 



of alumina cream, and 1.5 cc. of lead subacetate. Shake thoroughly, 
and allow to stand from forty-five to sixty minutes. Place the tube in 
its holder in the centrifuge shield, and run six minutes. If, after the 
end of this time, any material adheres to the sides of the wide part of the 
tube, loosen with a small wire or by giving the tube a Ught twist, then 
run the tube six additional minutes, and finally read the volume of the 
precipitate in the stem, estimating to o.oi cc. 

Run a blank with the above reagents in water, subtracting the blank 
reading from that of the precipitate. In the case of syrup, reduce to 
the 5 -gram basis by dividing by the specific gravity of the sample. If 
the sugar content of the sample is known, the specific gravity can be 
calculated from the table on page 499. For pure maple syrup 1.33 is 
ver>' nearly correct. 

The following table shows results obtained by Hortvet on two samples 
of maple syrup of known purity, mixed with varying amounts of refined 
cane sugar syrup of the same density: 







Com- 






Com- 






Com- 




Purity. 


Five 


puted 


Differ- 


Ten 


puted 
Precipi- 


Differ- 


Twelve 


puted 
Precipi- 


Differ- 


Minutes. 


Precipi- 


ence. 


Minutes. 


ence. 


Minutes. 


ence. 






tate. 






tate. 






tate. 




Per Cent. 


cc. 


cc. 


cc. 


cc. 


cc. 


cc. 


cc. 


cc. 


cc. 


100 


4-9° 






3-29 






2.80 






25 


I. 00 


1.22 


0.22 


0. 70 


0.82 


0. 12 


0.65 


0.70 


0.05 


50 


3.60 


2.4s 


115 


1.50 


1-54 


0.14 


1.40 


1.40 


0.00 


75 


4.60 


367 


0-93 


2.77 


2.47 


0.30 


1.90 


2. 10 


0.20 


100 


5.40 






4.40 






3-75 






10 


0.30 


0.54 


0.24 


0.28 


0.44 


0.16 


0.28 


°-37 


0.09 


20 


1.27 


1.08 


0. 19 


0.80 


0.88 


0.70 


0. 70 


0-75 


0.05 


60 


5.00 


3-24 


1.76 


2. 70 


2.64 


0.06 


1.70 


2.25 


0-55 



The blank at the end of twelve minutes was 0.44 cc. The machine 
used for the above experiment had a radius of 18.5 cm., and a speed of 
1600 revolutions per minute. Results obtained by Hortvet on known 
pure maple syrups vary from 1.2 cc. to about 2.5 cc, and on known 
pure maple sugars from i .8 cc. to 4 cc. 

Commercial brands of adulterated syrups and sugars give such pre- 
cipitates as 0.00 cc, 0.02 cc, 0.05 cc, and 0.08 cc Hortvet regards with 
suspicion a syrup testing lower than 1.2 cc, and when the result is below 
I cc, the sample is positively condemned as being mixed with refined 
cane sugar. In the case of sugar, a somewhat higher minimum figure 
is adopted than with syrup. In view of the fact that the speed has much 
to do with the volume of the precipitate, the analyst should make a series 



POLARIZ/ITION OF COMMERCIAL GLUCOSE. 769 

of similar experiments with his own centrifuge, and work out his own 
standards. Results may be better compared with each other, if calculated 
on the water-free basis. 

In case of doubt, and in fact in all cases at first, it would be well 
to make confirmatory tests, such as determining the ash and reducing 
sugar. 

Data on the Ash of Maple Products. — C. H. Jones, of the Vermont 
Experiment Station, has furnished the data found in the table on p. 770. 
Samples marked pure were of unquestioned authenticity, and, unless 
otherwise specified, were of high grade. 

Pure maple products from farmers rarely run below 0.6% in total 
ash, while pure manufactured maple syrups are sometimes lower, due to 
more complete settling and separation of the sediment by filtration. 

Jones places the lowest limit of ash in pure maple syrup as 0.5%, 
on the basis of 11 pounds of syrup to the gallon. 

POLARIZATION OF COMMERCIAL GLUCOSE. 

In the formula given on page 505 for determining commercial glucose 
in molasses and syrup, 175 has been assumed as the maximum polariza- 
tion of 42° Be. glucose, based on the previous experience of the author. 

It seems to be a fact that the polarization of this grade of glucose is 
somewhat lower now than formerly. The analyst is therefore recom- 
mended to keep informed by experiment from time to time as to its hmits 
of polarization, and to use the highest limit found as a factor in the 
formula. 

Whatever factor be adopted, however, by always expressing the final 
result in terms oj glucose polarizing at thai jactor, a definite statement is 
made. In the case of honey and similar products, note the correction 
given on page 515, to be appUed to the assumed factor. 



77° 



POOD INSPECTION /IND ANALYSIS. 



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INDEX. 



Abbe refractometer, 389, 397 
Abrastol, 678 
Abrus, 38 
Absinthe, 605 
Acetyl value, 400 
Acid fuchsin, 64-4, 652 
Acids, fatty, 371, 375, 402, 403 
of acetic series, 368 
of linoleic series, 369 
of oleic series, 369 
mineral, in vinegar, 616, 617 
organic, 42 
Adams' fat method, 98 
"Aerated" butter, 438 
Agar ajrar, in jelly, 724 
Aging of liciuors, 594, 59^ 
Albumin, determination in milk, no 
of muscle, 165 
preparation of, 205 
Albuminates, 38 
Albuminoids, 39 
Albumins, 37, 229 
Albumose, 38 
Alcohol, detection, 527 

determination, 528 

by distillation, 528 
by ebulioscope, 545 
by evaporation, 530 
from specific gravity, 529 
extract of spices, 312 
methyl-, 743 
preparation of, 593 
stills, 530 
tables, 531-544 
Alcoholic beverages, see also liquors, 523, 524 
references on, 607 
state control of, 524 
toxic effect of, 525 
fermentation, 523 
Ale, 576 
Aleurone, 78 
Alkaloidal nitrogen. 41 
Alkaloids, proof of absence of, 590 
Alkanna tincture, 80 
AUantoin, 231 
AUihn's sugar method, 493 

tables, 494 
Allspice, 323 

adulteration, 326 
microscopical structure, 324 



Allspice, standard, 326 
tannin in, 326 
Almond extract, 748 

adulteration of, 749 
; ■ alcohol in, 751 

benzaldehyde in, 750 
hydrocyanic acid in, 740 

751 
nitro benzol in, 749 
Almonds, bitter, oil of, 747, 748 
Alum in baking powder, 255, 263 
in bread, 248 
in flour, 237 
in pickles, 712 
Alumina, determination of, 263 
Aluminum salts in baking powder, 263 
in cream of tartar, 263 
Amides, 40 

in milk, in 
Amido acids, 40 
Amido nitrogen determination, 64, in 

in wheat, 231 
Ammonia, determination, 64 

in baking powder, 265 
in foods, 41 
in milk, i ir 
Ammonium fluoride, 676 
Amylodextrin, 363 
Amyloid, 70, 80 
Analyst, functions of, 3-4 
Angostura, 605 

Anilin orange in milk, 134, 135 
Annatto in butter, 435, 436 
in milk, 134,' 135 
tests for, 637 
Antipeptones, 39 
Antiseptics, see also preservatives 

regulation of, 662 
Apparatus, 18 

Apple essence, artificial, 752, 753 
Apple juice, 550 

Apples, composition of, 215, 216, 550 
Araban, 226 
Arabinose, 22^, 226 
Arata's color method, 641 
Amiagat and Jean's refractometer, 389 
Army rations, 201 

Arsenic detection and determination, 64, 65 
compounds in colors, 631 
Gutzeit test for, 511 

77' 



772 



INDEX. 



Arsenic in beer, 580, 591, 592 
in vinegar, 626 
Marsh apparatus, 65 
Artificial colors, 628 

fruit essences, 751 
sweeteners, 682 

references on, 687 
Asaprol, 678 

Asbestos fiber, preparation of, 489 
Ash, determination of, 55 

of food, 42 
Asparagin, 40, 231 
Auramin, 630 

Babcock fat method, 100 

milk formula', 115 
test bottles, 102 
Badouin's sesame oil test, 420 
Baking powders, 254 

adulteration of, 256 
alum, 255 
phosphate, 255 
tartrate, 254 
Banana essence, artificial, 752, 753 
Barium compounds in colors, 630 
Bark as an adulterant, 330 
Barley, 213, 242, 243 

proteids, 218, 233 
starch, 221 
Basic colors, 639, 643 
Beading oil, 597 
Beans, 213 

Beaume and Brix scales compared, 499 
Bechi's cottonseed oil test, 418 
Beef, composition of, 167 

cuts of, 165 

stearin, microscopical structure, 455 

tallow, 430 
Beer, 574 

acids in, 588 

adulteration of, 578 

aloes in, 591 

analytical methods, 581 

arsenic in, 580, 591, 592 

ash of, 579 

bitter principles of, 590 

bock-, 576 

brewing of, 575 

capsicin in, 597 

carbon dioxide in, 589 

chiretta in, 591 

composition of, 576 

extract gravity of, 587 

extract in, 581, 583-586 

gentian bitter in, 591 

glucose in, 577, 579 

lager-, 575 

phosphoric acid in, 588 

preservatives in, 580 

proteids of, 588 

quassiin in, 590 

references on, 607 

schenk-, 575 



Beer, standards, 578 

temperance-, 580 
varieties of, 575 
uno-, 581 
weiss-, 576 
wort, 581 

gravity of, 581-587 
Beeswax, 515 

refractomcter reading of, 516 
Beet (color), 636 
Bellier's, peanut oil test, 425 
Benches, 13 
Benedictine, 605 
Benzaldehyde, 748, 750 

artificial, 751 
Benzoic acid, 673 

detection of, 142, 673, 674 
in milk, 142 
Betaine, 40, 231 
Beta-naphthol, 677 
Bigelow and McElroy's cane-sugar method, 

152 
Bilberry (color), 636 
Birotation, 469, 479 
Bisulphites as preservatives, 675 
Bitter almonds, oil of, 747 
Biuret reaction, 37 
Blackberry (color), 636 
Blast pump, 17 
Blue colors, 631, 658 
"Blown" cans, 692 
Bock beer, 576 
"Boiled" butter, 438 
Bombay mace, 365 
Bomb calorimeter, 42 
Borax, 667 
Boric acid, 667 

detection, 142, 668 
determination, 667, 669, 670 
in butter, 436 
in meat, 174, 185 
in milk, 142, 144 
Bourbon whiskey, 595 
Brandy, 597 

adulteration of, 598 
"drops," 521 
standards, 598 
Bread, 244, 246 

acidity of, 247 
adulteration of, 248 
alum in, 248 
baking of, 245 
fat in, 248 
Breakfast cereals, 267, 268 
Brewing beer, 575 
Brie cheese, 158 

Brix scale compared with Beaume, 499 
Bromination oil test, 386 
Bromine absorption of oils, 385 
Brown colors, 632, 656, 658 

sugar, 463, 770 

Briicke's glycogen method, 1S8 

reagent, 18S 



INDEX. 



773 



Buckwheat, 213, t,t,() 
Burgundy wine, artificial, 560 
Butter, 157, 430 

adulteration of, 434 

analytical methods, 432 

annatto in, 435, 436 

ash in, 433 

azo colors in, 436 

boric acid in, 436 

carrotin in, 435 

casein in, 433 

coloring in, 434 

fat, composition of, 431 
standard, 433 

foam test, 446 

formaldehdye in, 437 

glucose in, 450 

microscopical examination of, 448 

milk test, 446 

preservatives in, 436 

references on, 458 

renovated, 43S 

salicylic acid in, 437 

salt in, 433 

standard, 433 

sulphurous acid in, 438 

Waterhouse test, 446 
Butterine, 438 
Butterine oil, 423 
Butyro-refractometer, 3go, 443 

critical line of, 443 

limits of butter readings, 444 

oil readings on, 398 

olive and cottonseed oil readings, 415 

special thermometer for, 445 

Caffeine, 280 

determination of, 2S1 
in cocoa, 303 
Cafleol, 289 
Caffetannic acid, 289 
Cake, 249 

Calcium carbonate crystals, 78 
oxalate cr)'stals, 78 
sucrate, 155 
California wines, 558 
Calorie, 42 
Calorimeter, bomb, 42 

oil, 387, 388 
respiration, 2 
Camera, 84 

Cammembert cheese, 158 
Canada balsam, 74 
Candy, see confectionery 

standard, 517 
Cane sugar, 461 

analysis of, 480 
ash of, 463 
composition of, 464 
detection of, 4S0 

in milk, 145 
determination of, 

by copper reduction, 497 



Cane sugar, determination of, by polarim- 
etry, 481, 508 
in cereals, 227 
inversion of, 483, 484 
manufacture of, 463 
moisture in, 481 
quotient of purity, 481 
refining, 466 
test for, 480 
Canned food, 689 

analysis of, 691 
antiseptics in, 705, 706 
composition of, 691 
decomposition of, 692 
impurities in, 692 
metaUic impurities in, 694 
method of canning, 690 
references on, 754 
Canned fruits, 6S9, 691 
meats, 17:; 
vegetables, 689, 691 
Cans, detection of spoiled, 692 
gases from spoiled, 693 
Capers, 711 
Capsicin, 342 
Caramel, 638 

in distilled liquors, 603 
in milk, 134, 136 
in vanilla extract, 739 
in Wnegar, 625 
Carbohydrates, 41, 42, 219 

of cereals, 218, 227 
of eggs, 205 
Carbon dioxide 

in baking chemicals, 259, 260 
in beer, 589 
in yeast, 250 
Carnin, 165 
Carrot (color), 637 
Casein, 38, 89 

determination in milk, 209 
Caseose, 38 

in cheese, 161 
in milk, m 
Cassia, 326 

adulteration of, 330 

buds, 327 

microscopical structure, 318 

oil, 327. 747 
standard, 330 
Cayenne, 341 

adulteration of, 343 

coal-tar colors in, 345 

colors in, 345 

microscopical structure, 343 

mineral adulterants in, 344 

oil of, 342 

redwood in, 345 

standard, 344 
Cazeneuve's color scheme, 572 
Cellulose, 79, Si, 218, 224 
Centrifuge, milk-fat, loi 
universal, 23 



774 



INDEX. 



Cereals, 212 

ash of, 223, 234 

breakfast foods, 267, 268 

cane sugar in, 227 

carbohydrates of, 218, 219 

separation of, 227 

composition of, 212 

crude fiber in, 218, 228 

dextrin in, 227 

hemicelluloses in, 228 

methods of proximate analysis, 217 

pentosans in, 228 

proteids of, 228 

references on, 273 

starch determination in, 228 
Champagne, 557 
ChaptaUzing, 561 
Chartreuse, 605 
Cheddar cheese, 158 
Cheese, 157 

adulteration of, 158 

amides in, 161 

ammonia in, 161 

ash in, 159 

composition of, 157 

cream, 158 

lactic acid in, 161 

fat in, 159, 162 

filled, 159 

milk sugar in, 162 

nitrogen, water soluble in, 161 

paranuclein in, 161 

peptones in, 161 

proteids in, 160 

sampling, 159 

skimmed milk, 162 

standards, 158 

varieties of, 157 

water in, 159 

whole milk, 158 
Chicon.', 294, 296 
Chih sauce, 709 
Chilton cheese, 158 
Chiretta, 591 
Chlor iodide of zinc, 79 
Cholesterol, 404, 408 
Cholin, 40, 231 
Chondrin, 40 

Chromate of lead, 519, 638 
Chromogenic bacteria, 94 
Cider, 54S 

adulteration of, 552 
ash of, 552 
composition of, 549 
fermented, 550 
maUc acid in, 569 
manufacture of, 548 
references on, 608 
sweet, 727 
vinegar, 610, 620 
watering of, 502 
yeast in, 548 
Cinnamon, 326, 328 



Cinnamon, microscopical stnjcta'"e of, 329 

standard, 330 
Citral, 745, 746 
Citric acid in milk, 01 

in fruit products, 723 
in lime juice, 727 
Citronellal, 746 
Citronclla oil, 745, 746 
Clams, 200 
Claret wine, 557 
Clarifying reagents 

in microscopy, 80 
in sugar analysis, 481, 502 
Clerget's formula, 483 
Cloves, 314 

adulteration of, 320 
cocoanut shells in, 321 
exhausted, 320 
microscopical structure, 318 
oil of, 747 
standard, 320 
stems, 319 
tannin in, 317 
Coal-tar colors, 639 

acid, 639, 640, 643 
Arata's method, 641 
basic, 639, O40, 643 
classification, 639, 644, 645 
detection of, 640 
double dyeing method, 641 
dyeing wool by, 640 
extraction by amyl alcohol, 

642, 643 
identification of, 650, 652 
in milk, 137 
in sausages, 190 
Rota's scheme for, 644 
separation with ether, 643 
Cochineal, 638 

in sausages, 190 
Cocoa, 299, 300 

adulteration of, 304 
albuminoids in, 304 
alkali in, 305 
analytical methods, 302 
ash of, 303 
butter, 304, 430 
caffeine in, 303 
microscopical structure, 306 
nibs, 299 

nitrogenous bodies in, 302 
references on, 30S 
shells, 307 
standards, 304 
starch in, 304, 30S 
sugar in, 308 
theobromine in, 302, 303 
Cocoanut oil, 429 
pulp, 429 
shells, 321, 322 
Coffee, 289 

adulteration of, 292 
analytical methods, 291 



INDEX. 



775 



Coffee, ash of, 2Q0 

caffeine in, 29 1 
caffetannic acid in, 289, 291 
cafleol in, 289 
chicory in, 294, 296 
coloring of, 208 
essential oil of, 289 
fat in, 289, 291 
glazing of, 298 
microscopical structure, 293 
"pellets," 292 
references on, 308 
starch in, 293 
substitutes, 298 
Cognac, 597 

oil, 598 
Collagen, 40, 165 
Collodion silk, 572 
Colors, artificial, 628 

acid fuchsin, 644 
arsenic compounds, 631 
barium compounds, 630 
basic, 643 

blue, 631, 632, 634, 658 
brown, 632, 634, 656 
caramel, 638 
chromate of lead, 638 
coal tar, 630 
cochineal, 63S 
copper compounds, 630 
cudbear, 637 

extraction of, by immiscible sol- 
vents, 642 
fuchsin, 643 

green, 631, 632, 633, 658 
harmless, 630, 632 
identification of, 650, 652 
indigo, 638 
injurious, 630, 631 
in butter, 434 
in cayenne, 345 
in confectionery, 518, 634 
in jams and jellies, 723 
in ketchup, 709 
in milk, 134, 137 
in mustard, 360 
in sugar, 466 
lead chromate, 638 
lead compounds, 630 
■ogwood, 637 
mercury compounds, 631 
. .lineral, 638 
:on-injurious, 630, 632 
orange, 630, 633, 636, 654 
orchil, 637, 642 
Prussian blue, 638 
reagents for identifying, 651 
red, 631, 632, 636, 652 
references on, 660 
Rota's scheme for, 644 
separation by solvents, 644 
toxic effect of, 629 
turmeric, 637 



Colors, ultramarine blue, 638 
vegetable, 635, 642 
violet, 632, 634, 65S 
wool dveing, 640, 642 
yellow, 631, 633, tib, 637, 654 
Colostrum, 93 

Commercial glucose. See Glucose 
"Compound" foods, 717 
Compressed yeast, 250 
Conalbumin, 204 
Concentrated foods, 201 
Condensed milk, 146 

analysis of, 148 
as a milk adulterant, 146 
ash o', 149, 152 
cane sugar in, 151, 152 
composition of, 147 
fat in, 149, 151, 152 
milk sugar in, 150 
proteids in, 150, 152 
solids of, 148 
standards for, 148 
Confectionery, 517 

alcohol in, 521 
analysis of, 518 
arsenic in, 521 
cane sugar in, 520 
colors in, 518, 521 
dextrin in, 520 
glucose in, 521 
invert sugar in, 520 
lead chromate in, 519 
iviineral adulterants, 519 
paraffin in, si 9 
starch in, 520 
Congluten, 38 
Connective tissue, 165 
Copper salts, 699 

determination ol, 702, 703, 704 
in vinegar, 626 
Copra oil, 429 
Cordials, 605 

analysis of, 606 
composition of, 606 
Corky tissue, 77 
Corn, 213, 244, 245, 422 

bleacliing of canned, 706 
oil, 422 

sitosterol in, 423 
proteids of, 218, 233 
starch, 221 
syrup, 470 
Corning of meat, 173 
Cottonseed, 417 

oil, 417 

tests for, 418 
stearin, 418 
Cotton's cane sugar method, 145 
Coumarin, 732 

determination, 737 
microscopical structure, 738 
Cream, 153 

adulteration of, 155 



776 



INDEX. 



154 



579 



Cream, analytical methods, 
cheese, 158 
evaporated, 146, 155 
gelatin in, 155 
standards for, 155 
sucrate of lime in, 155 
test scale, 152 
viscogen in, 156 

Cream of tartar, 257 

in wine, 

Creatin, 1O5 

Creatinin, 165 

Crem.e de menthe, 606 

Creme de Noyau, 605 

Crude fiber, 218 

in cereals, 228 

Crustaceans, 200 

Crystals, plant, 78 

Cucumber pickles, 711 

Cudbear, 637 

Cuprammonia, Si 

Curagoa, 605 

Curcuma, 350 

Curcumin, 351 

Curd tests in butter, 747, 7 

Curing meat, 173 

Currant (color), 636 

Curry powder, 350 

Custard powders, 210 



Dakota mustard, 360 
Date stones, 297 
Defren-O 'Sullivan sugar 
method, 114, 489 
Defrcn's sugar tables, 490 
Desiccated egg, 209 
Deutyro-albumose, 30 
Dextrin, 470 

determination of, 
in cereals, 2 28 
in glucose, 510 
in honey and molasses, 506 
Dextrose, 468 

determination of, 486, 487, 508 
Diastase in malt extract, 592, 593 

starch methods, 223 
Dietetics, references on, 44 
Distilled liquors, 593 

analytical methods, 601 
caramel in, 603 
ethereal salts in, 603 
furfurol in, 603 
fusel oil in, 601 
opalescence of distillate, 604 
references on, 608 
Double dilution sugar method, 113, 503 
Drains, 15 
Dry wines, 555 
Dry yeast, 250 
Dubosc's saccharimeter, 478 
Dulcin, 685 

determination, 686 
Dupr^'s color method, 572 



Ebulioscope, 545 
Edam cheese, 187 
Edestin, 231 
Eggs, 203 

analytical methods, 207 

ash of, 206 

carbohych-ates of, 205 

composition of, 203 

desiccated, 209 

fat of, 205, 206 

lecithin determination, 207 

physical examination of, 209 

preservation of, 208 

proteids of, 205 

references on, 211 

substitutes for, 209 

waterglass as a preservative, 208 

weights of, 206 

white of, 204 

yolk of, 205 
Elaidin oil test, 402 
Elastin, 40, 165 
Elderberry (color), 636 
Electrolytic apparatus, 493 
Elm bark, 330 
Emergency rations, 201 
Ergot, 239 

Essential oils, 745, 747 
Ether, ethyl-preparation of absolute, 58 

pretroleum, preparation of, for a sol- 
vent, 58 
Eucasin, 122 
Eugenol, 314 
Ewe's milk, 91 
Exhausted cloves, 320 
ginger, 347 
tea leaves, 285 
vanilla beans, 731 
Exhaust pump, 18 

Extraction with immiscible solvents, 60 
volatile solvents, 58 

"Faints," 595 

Farinaceous infants' foods, 270 

Fat globules, 7S 

Fat of food, 35 

of meat, 179 
Fats, edible, 368. See also Oils, 
filtering, 370 
measuring, 370 
melting point of, 374 
microscopical examination of, 409 
paraffin in, 409 
weighing, 370 
Fatty acids, 402, 403 

constants of, 403 
insoluble, 378 
solidifying point of, 403 
soluble, 371 
volatile, 375 
Fehling processes, 485 

gravimetric, 488 
volumetric, 486 



INDEX. 



777 



Fehling's solution, 485 

equivalents of, 487 
Fermentation, acetic, 609 

alcoholic, 523 
lactic, 93 

proteolytic, 122, 157 
Fermented liquors, 548 
Feser's lactoscope, 127 
Fibrin, Sg 

Fibro vascular tissue, 76 
Filled cheese, 159 
Fish, composition of, 198 
preservatives in, 201 
Flavoring extracts, 728, 747 

references on, 754 
Flesh bases, 165, 184, 192 
foods, 165 

references on, 202 
Floor, 13. 
Flour, 235, 241 

adulteration of, 237 
alum in, 237 

cold water extract of, 238 
gluten in, 238 
inspection, 236 
Fluoborates, 676, 677 
Fluorides, 676 
Fluosilicates, 676, 677 
"Foam" test for butter, 446 
Food adulteration, 5 

analysis from dietetic standpoint, 2 
analysis, general methods, 4 

references 'on, 67 
concentrated, 201 
economy, references on, 44 
inspection, 3, 5, 6, 9 

references on, 10 
nature and composition of, 35 
standards, 3 
state control of, i 

references on, 10 
Fore milk, 92 
Foreshots, 595 
Formaldehyde, 138, 144, 664 

detection of, 140, 666 
determination of, 141, 665, 

667 
resorcin test for, 666 
Fortified wine, 555 
Frozen milk, test for, 93 

meat, igi 
Fruit, 216 

candied, 519 
composition of, 215 
essences, artificial, 751, 753 
juices, 714, 715, 725, 726 
methods of proximate analysis, 217 
products, 689 

references on, 754 
references on, 273 
sugar. See Levulose. 
sugar-coated, 519 
sugar in, 462 



1 Fruit, syrups, 728 

tissues under the microscope, 725 
Fuchsin, 643, 648 
Fuel value, 42 
Funnel, jacketted, 371 
Furfurol, 226, 421 

in distilled liquors, 605 

in vinegar, 625 
Fusel oil, 593, 594 

detection, 601 

determination, 601 

toxic effect of, 597 
Fustic, 636 

Game, composition of, 170 
Gases, in spoiled cans, 693 
Geissler's carbon dioxide apparatus, 435 
Gelatin, 40, 165 

in cream, 155 

in meat, 183 
Gerber's milk centrifuge, too 
Gill and Hatch's oil calorimeter, 387 
Gin, 600 
Ginger, 345 

adulteration of, 350 

black, 346 

cold water extract of, 348 

exhausted, 347 

liming of, 346 

microscopical structure of, 349 

oil of, 346, 747 

root, 346 

standard, 350 

white, 346 
Gliadin, 230, 232 
GlobuUns, 37, 229 
Globulose, 38 
Glucin, 687 
Glucose, 470 

analysis of, 509 

arsenic in, 511 

composition of, 471 

determination of, in honey, 514, 769 
in molasses, 505, 
769 

dextrin in, 510 

healthfulness of, 471 

in beer, 577, 579 

in butter, 450 

polarization of, 769 

test for, 510 
Glucoses, 461 
Gluten, 230, 231, 238 
Gluten flour, 239 
Glutenin, 230, 232 
Glycerin in vanilla extract, 73S 

in wine, 570 
Glycerin jelly, 74 
Glycogen, 166 

detection, 187 
determination, 188 
Goat's milk, qi 
Graham flour, 236 



773 



INDEX. 



Grape juice, 726 

Grape sugar. See Dextrose 

Grape sugar, standard, 469 

Green colors, 631, 658 

Groats, 235 

Gruyere cheese, 158 

Gums, 77 

Gunning-Arnold nitrogen method, 334 

Gunning nitrgoen methods, 61, 63 

Gutzeit arsenic test, 511 

Haemoglobin, 165 

Halphen cottonseed oil test, 4ig 

Hanus' iodine absorjition method, 3S3 

Hefelmann's Bombay mace test, 365 

Hehner and Richmond's milk formula, 115 

Hehner's method for insoluble fatty acids, 379 

Heidenhain's tartaric acid method, 262 

Hemicellulose, 225, 228 

Hemipeptones, 39 

Hetero-albumose, 38 

Hock wine, 559 

Hoffmeister's schalchen, 58 

Holstein cows, milk from, 124 

Honey, 511 

adulteration of, 513 

analysis of, 512 

composition of, 511 

gelatin in, 513 

glucose in, 514, 769 

invert sugar in, 513 
Hoods, 14 
Hops, 575 

substitutes, 577 
Horseflesh, characteristics of, 186 
composition of, 1 76 
detection of, 187, 189 
glycogen in, 1S7 
Horse radish, 712 
Hortvet's maple sugar method, 767 
Hubl's iodine absorption method, 380 
Human milk, 91, 119 
Hungarian red pepper, 341 
Hunt's iodine reagent, 384 
Hydrocyanic acid, 749, 751 
Hydrometer, 49 
Hypoxanthin, 165 

Immersion refractometer, 757 

adjustment of scale, 764 
distilled water readings on, 763 
milk examination by, 765 
scale readings compared with no, 

L 759 

solutions standardized by, 764 

references on, 767 

temperature corrections for, 763 
Incinerator, 133 
Indicators, 134 

Indices of refraction, 394, 759 
Indigo, 638 
Indol, 80 
Infants' foods, 269 



Infants' foods, analytical methods, 271 
classification of, 269 
cold water extract of, 272 
microscopical examination of, 

273 
preparation of, 269 
Inosite, 166, 217 
Inspection of foods, 3, 5, 6, 9 

flour, 536 

hquors, 525 

milk, 123 
Inulin, 217 
Invalids' foods, 260 
Inversion, 461 
Invert sugar, 484 

detection of, 484, 507 

determination of, 486, 487 
Iodine absorption of oils, 380, 383, 384 
Iodine in potassium iodide, 79 
Irish whiskey, 595, 597 

Jams, 712. See also Jellies 

adulteration of, 713, 717 
analysis of, 71.S 
apple stock in, 725 
composition of, 715 
dextrin in, 722 
glucose in, 721 
polarization of, 719 
starch in, 724 
sugars in, 719, 721 
Jellies, 712, 713. See also Jams 

adulteration of, 713, 716 

agar agar in, 724 

analysis of. 718 

coagulator in, 716 

coloring matter in, 723 

composition of, 714 

gelatin in, 724 

glucose in, 721 

preservatives in, 724 

sugars in, 7x9, 720 

Kephir, 122 
Ketchups, 707, 708 

colors in, 710 

preservatives in, 710 
Knorr's carbon dioxide apparatus, 260 

method of nitrogen separation, 180 
Koettstorfer's saponification method, 379 
Koumis, 122 

Laboratory benches, 13 

drains, 15 

equipment, 12, 13 

references on, 34 

floor, 13 

hoods, 14 

lighting, 13 

location, 12 

sinks. 15 

ventilation, 13 
I^ctalbumin, 89 



INDEX. 



779 



Laclated infants' foods, 270 
Lactoglobulin, 89 
Lactometer, 95, 127 
Lactoscope, 127 
Lactose, 472 

detection of, 507 

determination of, 486, 488, 50S 
in milk, iii 
Soxhlet's table for, 116 
Lager beer, 575 
Lamb, composition of, 169 

cuts of, i6g 
Landwehr's glycogen method, 18S 
Lard, 451 

adulteration of, 453 
back, 451 
"compound," 453 
iodine number, 456 
kettle rendered, 451 
leaf, 452 

microscopical examination of, 454 
neutral, 452 
oil, 452 

references on, 459 
standards, 453 
stearin, 453 
substitutes, 456 
Laurent's saccharimeter, 478 
Lead chromate, 519, 638 
Lead, salts of, 694, 608 

determination of, 701, 702, 704 
Leavening materials, 249 

references on, 275 
Lecithin, 41 

determination of, 207 
Leffmann and Beam's method for volatile 
fatty acids, 377 
milk centrifuge, 100 
Legtunes, 213 

ash of, 234 
Legumin, 38 
Lemon extract, 739 

adulteration of, 739 
alcohol in, 742 
analysis of, 741 
citric acid in, 744 
colors in, 744 
composition of, 741 
lemon oU in, 742, 744, 745 
methyl alcohol in, 743 
standard for, 739 
tartaric add in, 744 
Lemongrass oil, 745, 746 
Lemon juice, 727 
Lemon oil, 745, 747 

determination of, 742 
Lentils, 213 
Leucosin, 231 

Levallois' bromine absorption method, 3S5 
Levulose, 469 

determination of, 486, 4S7, 508 
Liebig's meat extract, 192 
Lighting, 13 



Lignin, So 

Lime, determination of, 264 
in spices, 312 
juice, 727 
sucrate of, 155 

water, in vinegar analysis, 615 
Liming of ginger, 346 
Limonene, 746 
Liqueurs, 605 

analysis of, 606 
Liquor inspection, 525 
Liquors, alcohol in, 527, 528 

analytical methods, 527 
ash of, 547 
distilled, 593 

analytical methods, 601 
extract of, 547 
fermented, 548 
malted and non-malted, 578 
preservatives in, 547 
specific gravity of, 527 
Lobster, composition of, 200 
Logwood, 637 
Long pepper, 340 
Low wines, 595 

Macaroni, 266 
Macassar mace, 365 
Mace, 360, 363 

. adulteration of, 364 
Bombay, 365 
Macassar, 365 

microscopical structure of, 364 
oil of, 747 
standard, 364 
Madeira wine, 557 
Maize. See Corn 
Malaga wine, 560 
MaUc acid in cider, 569 

in vinegar, 617 
in wine, 569 
Mallet's phosphotungstic acid method, 182 
Mah, 574 

extracts, 185, 224, 592, 593 
Hquors, 574, 578 
substitutes, 577 
vinegar, 612 
Mahing, 574 
Maltose, 469 

detection of, 507 
determination of, 486, 488, 508 
Maple sap, 466 
sugar, 466 

adulteration of, 467, 767 
ash of, 467, 769, 770 
syrup, 466 

adulteration of, 467, 767 
ash of, 467, 769, 770 
Maraschino, 605 
Mare's milk, 91 
Marigold, 637 

Marpmann's color method, 191 
Marsh arsenic apparatus, 65 



7So 



INDEX. 



Martin's color scheme, 434 
"Matcrna" milk modifier, 121 
Maumene thermal test, 386 
Mayrhofer's glycogen method, iSg 
McGiU's dr\-ing oven, 481 
Meal, microscopical examination of, 239 
Meat, 165 

antiseptics in, 174 
bases, 165, 184, 192 
boric acid in, 174, 185 
canned, 176 
canning of, 175 
colors in, 190 
composition of, 165, 176 
cooking, effect of, 174 
corning of, 173 
curing of, 173 
extracts, 192, 194 

albumin, acid, 197 

coagulable, 197 
albumoses. 197 
amido nitrogen, ig6 
ash in, 195 
fat in, 195 

flesh bases in, 196, 197 
meat fiber in, 197 
nitrogen compounds of, 196 
peptones in, 197 
preservatives in, 198 
proteoses in, 197 
fat, composition of, 179 
fiber determination, 181 
gelatin determination, 183 
inspection, 171 
manufactured, 172 
nitrates in, 184 

nitrogen determination, 180-182 
nitrogenous bodies, separation of, 180 
peptones in, 165, 181 
phosphotungstic acid method, 182 
pickled, 172 
prepared, 179 
preservation of, 172 
preser\'atives in, 174, 184 
proteoses in, 165, 181 
ptomaines in, 172 
refrigeration of, 173 
salicyUc acid in, 174, 185 
salted, 172 
smoked, 172 
sound, 171 
standards of, 172 
sulphurous acid in, 174, 184 
unwholesome, 171 
Melting point, 374 
Mercury compounds in colors, 631 
Metallic salts in canned goods, toxic effects 

of, 701 
Methyl alcohol, detection of, 743 
Micro-chemical reactions, 82 
Micro-polariscope, 72 
Microscope, in food analysis, 69 

references on, 86 



Microscope, reagents for, 78 

stand, 70 
Microscopical diagnosis, 74 
Milk, 88 
Milk, acidity of, 117 

adulteration of, 123, 124 

aniUn orange in, 134, 135 

annatto in, 134, 135 

ash of, 91, 98 

ashing of, 133 

ass's, 91 

boiled milk, detection, 119 

boric acid in, 142 

caramel in, 134, 136 

carbonate in, 142 

citric acid in, 91 

coloring matter in, 134-137 

composition of, 88-90 

ewe's, 91 

fat of, 91, 98 

fermentations of, 93 

foods, prepared, 121 

fore milk, 92 

formaldehyde in, 138, 140 

goat's, 91 

human, 91, 119 

inspection, 123 

known purity, 124, 125 

mare's, 91 

microscopical appearance, 88 

modified, 119 

nitrogen compounds in, 89 

powder, 121 

preservatives in, 137, 143 

proteids of, 89 

records of analysis of, 132 

references on, 163 

ropy, 94 

sampler, 95 

serum, refraction of, 129, 765, 767 
specific gravity of, 129 

skimmed, 125 

sour, analysis of, 146 

souring of, 93 

standards, 124, 126 

strippings, 92 

sugar, 472 

determination of, 486, 488, 490 
determination of, in milk, iii, 

"3 
systematic examination of, 129, 135, 

143 
total solids in, 97 

calculation of, 115, iiS 
watering of, 124, 765 
MilUau's cottonseed oil test, 419 
MiUon's reaction, 36 
reagent. So 
Mill's bromine absorption method, 385 
Mineral colors, 638 
Mineral content of food, 42 
Mirbane, oil of, 749 
Modified milk, 1 19 



INDEX. 



■jSi 



Moisture, determination of, 55 
Molasses, 463, 464 

adulteration of, 504 

analysis of, 498 

ashing of, 506 

clarifying, 502 

glucose in, 505, 769 

standard for, 506, 507 

sucrose in, 498 

tin in, 507 

vinegar, 613 
Mollusks, 200 
Mucin, 40 
Mucoid proteid, 91 
Muscle albumin, 165 

fibers in meat, 165 
sugar, 166, 190 
Muscovado, 464 
Mustard, ^!\^ 

adulteration of, 359 

ash of, 357 

black, 353 

cake, 355 

coloring matter in, 360 

Dakota, 360 

fiour, 354 ^ 

microscopical structure of, 358 

oil, fixed, 354, 426 
volatile, 353, 357 

pickles, 711 

sinalbin in, 354 

mustard oil, 354 

sinapin sulphocyanate, 357 

standard, 359 

starch in, 359 

turmeric in, 360 

volatile oil of, 353 

wheat in, 359 

white, 353 
Mutton, composition of, 169 

cuts of, 169 

tallow, 430 
Myosin, 37, 149 

Natural wine, 555 

Neufchatel cheese, 158 

Nickel salts, 701 

determination of, 705 

Niebel's glycogen method, 18S 

Nitrates in food, 41 

Nitrobenzol, 749, 750 

Nitrogen compounds in milk, 11 1 

Nitrogen, determination of, 61, 63 

Nitrogen free extract, 48 

Nitrogenous bodies 

classification of, 36 
separation of, in cheese, 160 
in meat, 180 
in milk, iii 

Noodles, 266 

Notification, 9 

Noyau, 605 

Nuclein, 40 



Nutmeg, 360, 361 

adulteration of, 362 

Macassar, 363 

microscopical structure of, 362 

oil of, 747 

standard, 362 
Nutrose, 121 
Nuts, composition of, 216 

Oats, 213, 218, 242, 244 

starch in, 221 
Oil calorimeter, 387, 388 
Oil, bitter almond, 747, 748 

cassia, 327, 347 

clove, 747 

cocoanut, 429 

corn, 422 

cottonseed, 417 

ginger, 346, 747 

lard, 452 

lemon, 742, 744, 745 

lemongrass, 745 

mace, 747 

mustard, fixed, 354, 426 

volatile, 353, 357 

nutmeg, 747 

oleo, 439 

olive, 412 

orange, 747 

peanut, 423 

peppermint, 747 

poppyseed, 427 

rape, 421 

rosin, 428 

sesame, 419 

spearmint, 747 

sunflower, 427 

wintergreen, 747 
Oils, edible, 368. See also Fats 
acetyl value, 400 
analysis of, 370 
bromine absorption of, 385 
bromination test, 386 
cholesterol in, 404, 406, 408 
constants of, 410, 411 
elaldin test, 402 

fatty acids in, 375, 377, 402, 403 
iodine absorption of, 380, 38^, 

384 
judgment as to purity of, 370 
Maumene test, 386 
melting point, 374 
microscopical examination of, 

409 
phytosterol in, 404, 406, 408 
rancidity of, 370, 431 
references on, 457 
refractometer for, 389 
Reichert-Meissl number, 375 
saponification of, 369, 379 
sitosterol in, 423 
specific gravity of, 371 

factors, 372 



782 



INDEX. 



Oils, edible, thermal tests, 385 
titer test, 403 

unsaponifiable matter in, 403 
viscosity of, 374 
Oils, essential, 745 
Oleomargarine, 438 

adulteration of, 451 

constants of, 441 

healthfulness of, 440 

how distinguished from butter, 440, 

442 
manufacture of, 430 
microscopical structure of, 449 
odor and taste, 441 
Zega's test for, 450 
Oleo oil, 439 
Olive, composition, 412 
OUve oil, 412 

adulteration of, 413, 416 
examination of, 416 
refraction of, 415 
standard, 414 
Olives, pickled, 711 
Olive stones, 338 
Orange colors, 630, 654 
extract, 748 
oil, 747 
Orchil, 637, 642 

O'Sullivan's sugar methods, 114, 489 
Ovalbumin, 204 
Oven, drj-ing, 20 

McGill's, 481 
Ovomucin, 204 
Ovomucoid, 205 
Ox>-gen absorbed, 317 

equivalent, 318 
Oysters, 200 

Palas rapeseed oil test, 422 

Paprika, 341 

Paraffin in confectionery, 519 

in fats, 409 

in honey, 516 

in oleomargarine, 451 
Paranuclein, 161 
Parenchyma, 75 
Pastes, edihile, 266 
Pea, 213 

proteids of, 233 
starch of, 222 
Peanut oil, 423 

adulteration of, 424 
tests for, 424-426 
Pear cider, 553 

essence, artificial, 752, 753 
Pectose, Si, 217 
Pentosans, 225, 228 
Pentose, 226 
Pepper, 330 

adulteration of, 337 

black, 331 

buckwheat in, 339 

dust, 3 58 



Pepper, long, 340 

microscopical structure of, 335 
nitrogen in, 334 

in ether extract, 335 
olive stones in, 338 
piperin in, 33T 

determination of, 335 
red. See Cayenne 
shells, 337 
standard, 337 
white, 331 
Peppermint oil, 747 
Peptones, t,9> 

in cheese, 161 
in meat, 165, 181 
in milk, in 
Perry, 553 
Persian berries, 636 
Petroleum ether, 58 
Phloroglucide, 226 
Phloroglucin, 225 
Phosphate baking powders, 255 
Phosphoric acid in baking chemicals, 265 

in beer, 588 
Phosphotungstic acid method for nitrogen 
separation, 182 
reaction, 37 
Photomicrography, 81 

camera for, 84 
Phytalbumosc, 38 
Phytolacca, 636 
Phytosterol, 404, 408 
PiccalilH, 711 
Pickled meats, 172 
Pickles, 708, 711 

adulteration of, 711 
PickUng pump, 173 
Pineapple essence, 752, 753 
Pioscope, 128 
Fiotrowski's reaction, 37 
Piperin, 331 

determination of, 335 
Plant crystals, 78 
Plasmon, 122 
Plastering, 560 
Platinum dishes, 55, 56, 97, 98 

counterweights for, 130 
Poisoned foods, 64 
Poivrette, 338 

Polariscope, 473, 478. See also Saccharime- 
ter 
micro, 72 
Polariscope tube 

jacketted, 515 
short, for oils, 745 
Polarization at high temperature, 515 
of essential oils, 747 
honey, 513, 515 
lemon extract, 742 
molasses, 502 
orange extract, 748 
sugar, 4S2 
vinegar, 618 



INDEX. 



783 



Polarization of ^\'ine, 570 
Poppvseed, 427 

oil, 427 
Pork, composition of, 170 

cuts of, 170 
Porter, 576 
Port wine, 557 . 
Potash determination, 2O4 
Potassium myronate, 353. 3S7 

Potatoes, 214 

proteids of, 233 

starch of, 222 
Poultry, composition of, 17° 
Preparation of sample, 40 

P'-^^'^"^''^"' commercial food, 663 

in butter, 43>'' , 

in canned goods, 705, 70& 
in fish, 201 
in meats, 174, t»4 
in milk, 137, I43 
in table sauces, 710 
of eggs, 208 
references on, 679 
regulation of, 662 

Pressure pump, 18 
Process butter, 442 
Proof spirit, 547 
Prosecution, 9 
Proteids, 36 

insoluble, 39 

of barley, 218, 233 

of beer, 588 

of cereals, 228 

of condensed milk, 150 

of eggs. 205 

of milk, 80 

calculation of, 117 
determination of, 109 

of peas, 233 
of potatoes, 233 
of r\'e, 218, 232 
of wheat, 218, 230 

Protein, 48 

factor for, 48 
Protein grains, 78 
Proteolytic fermentation, 157 
Proteoses, 38, 220 ^ 
Proto-albumose, 38 

P---'^^™'>'^'^':^p7esrion''of results 

48 
Prussian blue, 638 
Ptomaines. 172 , t j ^ 

Publication of adulterated foods, 9 
Pulfrich refractometer, 389 
Pycnometer, 51 ^ 
Pyroligneous acid, 625 

Quassiin, 590 
Quercitannic acid, 318 
Quevenne's lactometer, 95 
Quince essence, artificial, 752, 753 



Quotient of purity of sugar, 481 

RafiSnose, 219, 47^ . 

determination ot, 503 

Rancidity, 37°, 43^ 
Rape oil, 421 

test for, 422 
seed, 421 
Raphides, 78 
Reagents, 31 

references on, 34 

table of, 24-30 
Red colors, 631, 636, 652 
Red ocher in sausages, 190 
Red pepper. See Cayenne 
Red wines, 554 
Redwood, 345 
References on beer, 607 

butter, 458 

cereals, 273 

cocoa, 308 

coffee, 308 

colors, 660 

dietetics, 44° 

distilled liquors, 608 

eggs, 211 

flavoring extracts, 754 

food economy, 44 
inspection, 10 

fruits, 273 

immersion refractometer, 767 
laboratory equipment, 34 
leavening matenals, 275 
microscope, 86 
milk, 163 
oils, 4,'; 7 
reagents, 34 
spices, 366 
sugars, 522 
tea, 308 
vinegar, 626 
wine, 608 
Refractometer, 389 

Abbe, 389, 397 „ 

Armigat and Jean, 389 
butyro, 3Q0, 443 
critical line, 443 
heater for, 391 
immersion, 757, 758 
Pulfrich, 389 
f I sliding scale for, 390 

° ' I tables for, 105, 394, 398. 759. 

763, 764 ^ 
Wollny, 103, 389 
Reichert-Meissl method, 375 
Reichert number of buUer, 445 
Reinsch's test for arsenic, 592 
Relishes, 708 
Renard's test for peanut oil, 424 

for rosin oil, 420 
Renovated butter, 438 

Resins, 77 

Respiration calorimeter, 2 



784 



INDEX. 



Rice, 213 

starch, 222 
Richmond's cane sugar method, 145 

sliding milk scale, 117 
Ritthausen's method for milk proteids, 109 
Roeser's mustard oil method, 357 
Ropy milk, 94 
Roquefort cheese, 158 
Rosin oil, 428 
Rota's color scheme, 644 
Rubner's fuel value factors, 43 
Rum, 599 

essence, 600 
standards, 599 
Rye, 213, 242 

proteids of, 218, 232 

starch, 221 

Saccharimeter, 473 

double wedge, 476 
forms of, 478 
normal weights for, 478 
scales compared, 478 
single wedge, 474 
Soleil-Ventzke, 473 
triple shadow, 476 
Saccharimetry, 473 
Saccharin, 682 

detection of, 683 
determination of, 684 
Saccharine products, 461 
Saccharoses, 461 
Safflower, 637 
Saffron, 637 
Sago, 223 
Saleratus, 258 
Salicylic acid, 671 

detection of, 143, 671 
determination of, 672 
in meat, 174, 185 
in milk, 143 
Salted meats, 172 
Sanatogen, 122 
Sanose, 122 

Saponification, 369, 379 
Sarcolemma, 165 
Sausages, 177 

ash of, 178 
color of, 177, igo 
fat in, 177 
glycogen in, 187 
horseflesh in, 187 
starch in, 185 
water determination, 178 
Sauterne wine, 555 
Sawdust, 350 
Schiedam schnapps, 600 
Schenk beer, 575 
Sclerenchyma, 75 
Scovell sampling tube, 95 
Sealed samples, 5, 123 
Semolina, 226 
Sesame oil, 419 



Sesame oil, adulteration of, 420 
tests for, 420 
seeds, 419 
Shern' wine, 557 
Shredded wheat, 266 
Sieve tissue, 77 
Silent spirit, 593 
Sinalbin, 353 

mustard oil, 353 
Sinigrin, 354 
Sinks, 15 
Sitosterol, 423 
Smoked meats, 172 
'Soaked" goods, 707 
Soda, determination of, 264 
Sodium benzoate, 673 

bicarbonate, 258 
bisulphite, 675 
carbonate, in milk, 142, 144 
hydroxide, tenth normal solution, 31 
salicylate, 671 
Soleil-Ventzke saccharimeter, 473 
Sorghum, 468 
Souring of milk, 93 
Sour milk, 103 
Soxhlet extractor, 57 
Soxhlet's milk sugar method, 114, 116 
Spaghetti, 260 
Sparkling wine, 555 
Spearmint oil, 747 
Specific gravity bottle, 51 

of beeswax, 515 
of liquids, 49 
of liquors, 527 
of milk, 95, 115 

serum, 129 
temperature correc- 
tion for, 97 
of oils, 371 
of vinegar, 614 
Specific rotary power, 479 
Spent tea leaves, 285 
Spices, 310 

adulterants of, 315 
alcohol extract of, 312 
analytical methods, 310 
ash of, 311 
crude fiber of, 313 
ether extract of, 312 
lime in, 312 

microscopical examination of, 314 
nitrogen in, 312 
references on, 366 
starch in, 313 
volatile oil of, 313 
Spiral ducts, 77 
Spirit vinegar, 610, 613 
Spoon test for butter, 44G 
Sprengel tube, 54 

Stahlschmidt's caffeine method, 281 
Standards for allspice, 326 
beer, 578 
brandy, 598 



INDEX. 



785 



Standards for butter, 433 
cassia, 330 
cayenne, 344 
cheese, 158 
cinnamon, 330 
cloves, 320 
cocoa, 304 
cream, 155 
ginger, 350 
grape sugar, 469 
lard, 453 

lemon extract, 739 
mace, 364 
meats, 172 
milk, 124, 126 
molasses, 507 
mustard, 359 
nutmeg, 362 
olive oil, 514 
pepper, 337 
renovated butter, 438 
rum, 599 
sugars, 462, 469 
vinegar, 619 
wine, 559 
whiskey, 596 
Standard solutions, equivalents of, 32 

refractometric readings 
of, 764 
Starch, 77, 219 

arrowroot, 222 
barley, 221 
bean, 222 
buckwheat, 222 
classification of, 220 
corn, 221 
detection of, 219 
determination of, 223 

by acid conversion, 223 
by diastase method, 223 
in baking powder, 262 
in cereals, 228 
in milk, 146 
in sausages, 185 
in spices, 313 
oat, 221 
pea, 222 
potato, 222 
rice, 222 
rye, 221 
sago, 223 
syrup, 470 
tapioca, 222 

under polarized light, 223 
wheat, 221 
State control, i, 3, 5, 9 

references on, 10 
Stearin, beef, 455 

cottonseed, 418 
lard, 453 
Sterilized butter, 438 
Still, alcohol, 530 

fractionating, 59 



Still, nitrogen, 63 

water, 20 
Still wine, 555 
Stilton cheese, 158 
Stokes' milk centrifuge, 100 
Stone's method of carbohydrate separation, 

227, 228 
Storch's proteid, 91 
Strippings, 92 

Stutzer's gelatin method, 183 
Suberin, 77 
Sucrate of lime, 155 
Sucrose. See Cane sugar 
Suction pump, 17 
Suet, 430 
Sugar, 461 

analysis of, 480 

beet, 465 

cane, 462, 463 

classification of, 461 

grape. See Dextrose 

in fruits, 462 

maple, 466, 767, 769 

muscovado, 464 

organic non sugars in, 481 

quotient of purity, 481 

raw, 463, 464 

references on, 522 

refining, 466 

standards, 462, 469 

ultramarine in, 466, 498 • 
Sulphuric acid 

in baking chemicals, 265 
in vinegar, 617 
Sulphuring, 675 
Sulphurous acid, 675 

detection of, 675 
detemiination of, 676 
in meat, 174, 184 
Sunflower oil, 427 

seeds, 428 
Sweeteners, artificial, 682 
Sweet wine, 555 
Syrup, analysis of, 498 

mafile, 466, 769 

mi.xing, 470 

starch, 470 

Table sauces, 709 

preservatives in, 710 
Tallow, 430 
Tannin in cloves, 317 
in tea, 281 
in wine, 571 
Tapioca, 222, 223 

Tartaric acid in baking powder, 261 
in fruit products, 722 
Tartrate baking powders, 257 
Tea, 276 

adulteration of, 284 
analytical methods, 279 
ash of, 278, 280 
astringents in, 2S7 



7S6 



INDEX. 



Tea, caffeine in, 280 

exhausted leaves in, 285 
extract of, 283 
facing of, 284 
foreign leaves in, 285 
leaf, characteristics of, 286 
microscopical examination of, 288 
references on, 30S 
spent leaves in, 285 
stems in, 286 
tablets, 287 
tannin in, 281 
theine in, 280 
Teller's method of separating wheat pro- 

teids, 231 
Theine, 280 
Theobromine, 302, 303 

Tin, actions of fruits and vegetables on, 695, 
697 
determination of, 703, 704 
salts in molasses, 507 
Titer test, 403 

Tocher's sesame oil test, 420 
Tomato ketchup, 70S 

coloring in, 709 
preservatives in, 70S, 710 
Tonka bean, 732 

tincture, 732 
Turmeric, 350 

as an adulterant, 352 
microscopical structure of, 351 
tests for, 353, 636, 637 

Ultramarine blue, 638 

in sugar, 466, 498 
Uno beer, 581 

Vacuoles in yeast cells, 252 
Vanilla bean, 729, 730 

exhausted, 731 
Vanilla extract, 729 

adulteration of, 733 
alcohol in, 732, 738 
alkah in, 732 
analysis of, 731 
artificial, 733, 734 
caramel in, 739 
composition of, 731 
coumarin in, 733 

determination of, 737 
glucose in, 739 
glycerin in, 73S 
prune juice in, 733 
resins in, 734 
tannin in, 735 
tonka in, 733 
vanil'iin in, 731, 735 
Vanillin, 730, 731 

determination, 735 
microscopical structure, 738 
Van Slyke's method of nitrogen separation 

in cheese, 157—160 
in milk, iii 



Vaporimeter, 545 

Veal, composition of, 168 

cuts of, 168 
Vegetable colors, 635, 642 

in sausages, 190 
Vegetables, 216 

ash of, 233 
composition of, 214 
methods of approximate analy- 
sis of, 217 
references on, 273 
Ventilation, 13 

Villevecchia and Fabris' sesame oil test, 420 
Vinegar, 609 

acidity of, 615 

acids of, 616 

adulterated, 624 

adulteration of, 619, 620 

alcohol in, 616 

analysis of, 614 

arst.iic in, 626 

artificial, 620 

ash of, 62 1 

solubility and alkalinity of, 614 

beer, 612 

caramel in, 625 

cider, 610 

artificial, 620 

composition of, 610 

copper in, 626 

distilled, 613 

extract of, 614 

furfurol in, 625 

glucose, 613 

hydrochloric acid in, 617 

lead in, 625 

lead acetate test for, 617, 625 

levulose in, 619 

malic acid in, 617 

malt, 612 

manufacture of, 610 

metallic impurities in, 625 

mineral acids in, 616, 617 

molasses, 613 

nitrogen in, 615 

phosphoric acid in, 614 

polarization of, 61S, 622 

reducing sugars in, 619 

references on, 626 

residue of, 620 

specific gravity of, 614 

spices in, 625 

spirit, 610, 613 

standards, 619 

sugars in, 622 

sulphuric acid in, 617 

tartrate in, 619 

tests on, 623 

varieties of, 609 

volatile acids of, 616 

wine, 611 

wood, 614, 625 

zinc in, 625 



INDEX. 



787 



Vinous fermentation, 524 
Viscogen, 156 
Viscosity of cream, 156 
of oils, 374 

Walnut ketchup, 709 

Water-bath, 19 

Water glass, 208 

Waterhduse butter test, 446 

Weiss beer, 576 

Werner-Schmidt method for fat in cheese, 160 

in milk, 103 
Westphal balance, 50 
Wheat, 213 

ash of, 234 
proteids of, 218, 230 
shredded, 266 
starch, 221 
Whiskey, 594 

adulteration of, 596. 
artificial, 596 
Bourbon, 595 
composition of, 595 
Irish, 595, 597 
manufacture of, 594 
standards, 506 
Wijs's iodine absorption method, 384 
Wild's saccharimeter, 478 
Wiley's bromine pipette, 387 

method for nitrogen separation in 
nTeat, 182 
Wiley and Ewell's double dilution sugar 

method, 113, 503 
Wine, 554 

acidity of, 564 
added alcohol in, 563 
adulteration of, s6o 
analytical methods for, 564 
Burgundy, artificial, 560 
California, 558 
cane sugar in, 561 
Cazeneuve's color method, 572 
chaptalizing, 561 
claret, 557 

artificial, 560 
classification of, 555 
coloring matter in, 57:, 573 
composition of S56 
cream of tartar in, 579 
"dry," 555 

Dupre's color method, 572 
extract in, 564, 565-567 
fortified, 555 

fruit other than grape, 563 
glycerin in, 570 
hocks, 559 
Madeira, 557 
Malaga, artificial, 560 



Wine, malic acid in, 569 

manufacture of, 554 

natural, 555 

non-volatile acids in, 568 

plastering, 560 

polarization of, 570 

port, 559 

potassium sulphate in, 571 

red, 554 

reducing sugar in, 570 

references on, 608 

sherry, 557 

artificial, 560 

sparkling, 555 

standards, 559 

still, 555 

sweet, 555 

tannin in, 571 

tartaric acid in, 568 

varieties of, 557 

vinegar, 611 

volatile acids in, 564 

watering of, 562 

white, 554 

yeast of, 554 
Wintergreen, oil of, 747 
Wollney milk fat refractometer, 103 
tables for using, 105 
table for converting Wollney de- 
grees into «D, 107 
Wood vinegar, 614, 625 
Wool, double dyeing method with, 641 

dyeing of, 640 

for color tests, 640 

vegetable colors on, 642 

Xanthin, 165 

Xantho-proteic reaction, 36 
Xylan, 226 
Xylose, 225 

Yeast, 249, 251 

adulteration of, 253 

ash of, 250 

compressed, 250 

dry, 250 

in cider, 548 

in wine, 554 

microscopical examination of, 250 

starch in, 253 

testing, 250 

vacuoles in, 250 
Yellow colors, 631, 636, 654 

Zega's test for oleomargarine, 450 
Zinc salts, 699 

determination of, 703 



PLATE I. 



CEREALS. 




Fig. 121. — ^Barley, Xiio. 

Transverse section, shomng in order, pericarp, 

seed coats, aleuronc layer, and starch cells. 



Fig. 122. — Barley, X55. 
Surface view of epidermis vrith hairs. 





'■b,^':~ 



i 



Fig. 123. — Barley, X125. 
Surface view of upper chaff layer. 



Fig. 124. — Barley Starch, X220. 



CEREALS. 



PLATE II. 




Fig 125. — BiK kwhcat, Xiio. 

Tratisverse section through part of pericarp, seed 

coat, and part of endosperm. 



Fig. 126. — Buckwheat, X no. 
Surface view of scutellum. 





Fig. 127. — Buckwheat, Xiio. 
Surface section, .'^leurone or proteid layer. 







aT ,■»."> v. ^-■- •^■-'^^^ 






Fig. 128. — Buckwheat Starch, X220 
Starch granules separated. 



PLATE III. 



CEREALS. 




/ 



,^' 




Fig. i2g. — Buckwheat Starch, Xno. 
Starch grains in masses. 



Fig. 130. — Com, Xno. 
Transverse section through pericarp, seed coat, 
protcid layer, and part of endosperm, showing 
starch cells. 




Fig. 131. — Corn, Xno. 
Surface view showing two layers of the mesocarp. 



Fig. 132. — Com, Xno. 
Surface section. Proteid layer. 



CEREALS. 



PLATE IV. 










Fig. i,^-;. — Corn Starrh, X220. 



... ••V;..? i- . ■ 









Fig. 1 54. — Cornstarch, X220. 
With polarized light. 




Fig. 135. — Oat, X no. 
Transverse section through chaEF. 



Fig. 136. — Oat, Xiio. 
Surface section. Proteid layer with fragments of 
epidermis and hairs 



PLATE V. 



CEREALS. 




Fig. 137. — Oat, Xiio. 
Surface view of upper chaff layer. 



Fig. 13S.— Oat, X^s. 
Surface view of epidermis and hairs. 




FlG. ijy. — IJaI btaich, X220. 



Fia. 140. — Rice, Xno 

Transverse section through seed coat and part of 

endosperm 



CEREALS. 



PLATE VI. 




Fig. 141. — Rice, Xiio. 
■Surface section through stanh cells. 



Fig. 142 — Rice, X no. 
Surface view of upper chaff laver 







I^IG. 143. — Rice Starch, X220 



Fig. IJ4.— Rve, X iS 
Transverse section through the entire grain 



PLATE VII. 



CEREALS. 




:> / 



Fig. 145. — Rye, Xiio. Fig. 146. — Rye, X no. 

Transverse section through pericarp, seed coat, Surface view of epidermis and underlying layers, 
aleurone layer, and starch cells of endosperm. 




Fig. 147. — Rye, Xiio. 
Surface view of epidermis and of seed coat. 



\ > -. 



V 




Fig. 14S.- R\c SuuLh, X220. 



PLATE VIII. 



CEREALS. 





Fig. 140- — W luat, <iio. Fig. 150. — Wheat, X no. 

Transverse section through pericarp, seed coat, Surface view of outer and inner epidermis .Mso 
proteid layer, and starch cells of endosperm. showing proteid layer 





Fig. 151. — Wheat, Xiio. 
Surface view of epidermis, with hairs. 






FlG. 152. — Wheat Siarch, X220. 



LEGUMES. 



PLATE IX. 



'^iS:^ 



L<^-'^^^^-§W' 






■9-4 ■ 



Fig. 15,^. — Bean, Xno. 
Transverse section through starch cells. 




■ ■^^■ 



Fio. 154. — Bean Starch, X220 






\. ' 



Fig. 153. IJl.ih, Xiio. Fig. 156. — Lentil, Xiio. 

Transverse section through hull, showing palisade Transverse section through hull and part of endo- 
cells of epidermis, and underlying hypoderma. sperm, showing some of the starch cells. 



PLATE X. 



LEGUMES. 





Fig 157 — Lentil, Xiio. 
Surface view of epidermis. 




Fig. 158. — Pea, Xiio. 
Transverse section through hull and seed coal, 
showing outer palisade cells and underlying 
hypoderma. 




Fig 159 — Pea. Xno 
Surface section through base of palisade layer. 



Fig. 160. — Pea, X no. 
Powdered pea hulls. 



PLATE XI. 



LEGUMES. 




Fig. i6i. — Pea, Xiio. 
Surface view of palisade cells. 



Fig. 162. — Pea, Xtio. 
Transverse section through starch cells. 




Fir.. K^v I'l-vi, ■ ;o. 
Transverse section through starch cells. 



Fig. 164. — Pea Starch X220. 



PLATE XII. 



MISCELLANEOUS STARCHES. 




Fig. i66. — Potato Starch, X220. 
With polarized light. 




Fig. 167. — .\rrowroot Starch, X 220. 



Fig. 168. — Tapioca Starch, X220. 
(Cassava.) 



TURMERIC. SAGO. 



PLATE XIII. 




Fig. 169. — Turmeric, X To- 
Transverse section through rhizome. 



' a: 

Fig. 170. — Turmeric, Xiio. 

Longitudin.iI section. Note spiral ducts through 

the center. 




Fig. 171. — Powdered Turmeric, Xiio. 

Showing starch grains, fragments of cell tissue, 

coloring matter, etc. 



PLATE XIV. 



COFFEE. 





Fig. i7_^. — Raw Cuffee, Xiio. Fig. 174. — Roasted Coffee, X130. 

Transverse section of outer portion of endosperm. Transverse section through parenchyma of endo- 
sperm. 




Fig. 17s. — Coffee, Xiio. 
Surface view of seed coat. 



Fig. 176. — Coffee, Xnc 

Roasted, ground coffee, showing fragments of 

endosperm parenchyma and of seed coat. 



PLATE XV. 



COFFEE. CHICORY. 




N- 



^. 



..^*^' 



\ 



•iT.^ 



'^'T 



Fig. 177. — Adulterated Coffee, X130. 
Dark masses of roasted pea starch are shown, 
with transparent fragments of the palisade 
cells of the pea-hull. 



Fig. 17S. — Adulterated Coffee, X130. 
The vascular ducts of chicory show most con- 
spicuously in this field. 




Fig. 179. — Chicory, X25. 
Transverse section through the root. 



Fig. iSo. — Chicory, Xiio- 
Transverse section. 



PLATE XVI. 



CHICORY. COCOA. 




Fig. i8i. — Chicory, Xiio. 
Tangential section, showing reticulated ducts and 
wood parenchyma. 



Fig. 182. — Chicory, Xiic 

Radial section, showing bark parenchyma and 

milk ducts. 




Fig. 1S3 — Chicory, Xiio. 

Roasted and ground, showing fragments of 

ducts and other tissues. 



Fig. 184. — Cocoa, Xiio 

Transverse section through periphery of seed, 

seed coats, and cotyledon. 



PLATE XVir. 



COCOA. 




Fig. i8,. — Poudered Cocoa, Xiio. 



I-"iG. i86. — Adulterated Cocoa, Xiio 

Showing admixture of arrowroot with the cocoa 

powder. 




Fig l.^;. — CuLua . shell, X no. 
Transverse section through epidermis, pulp, and 
mucilaginous layers of the pericarp and seed 
coat. 



Fig. iSS. — Cocoa Shell, Xno. 
Longitudinal section through shell 



PLATE XVIII. 



TEA. SPICES. 




Fig. 1S9.— Tea, ,-,55. 
Transverse section through midrib of leaf. Note 
the palisade layer below the upper epidermis, 
the inner wood vessels above the center, and 
the parenchyma of the pulp. 



Fig. 190. — Tea, Xiio. 
Surface view of lower epidermis, with stomata and 
one of the hairs. 




Fig. igi. — .\llspice, X9. 
Transverse section through the entire berry, show- 



ing the two cell 
each 



with kidney shaped seed in 



Fig. 192. — .\llspice. X70. 

Transverse section through pericarp, showing oil 

spaces and stone cells 



PLATE XIX 



SPICES. 




::\/^-r\^c::f 



Fig. 19J. — .\llspicc iced ;-:iio. Fig. 194. — .\llspicc Sted, Xiio. 

Transverse section through seed shell and part of Transverse section through the resinous portion of 
embryo, showing starch cells. the seed coat, showing port wine colored lumps 

of gum or resin. 




^ 



'4. 





Fig. 195. — Powdered .Allspice, Xiio. Fig. i';^. — Adulterated .Allspice, Xno. 

Showing stone cells, resinous lumps, and starch. Showing a large fragment of the seed skin of 

cavenne at the left. 



SPICES. 



PLATE XX. 




Fig. 197. — Cassia Bark, X45. 
Transverse section through the bark. 



Fig. iqS. — Cassia Bark, X45. 
Longitudinal section. 




Fig. 199. — Cassia Bark, Xiio. 
Transverse section, showing cork cells, parenchy- 
ma, and stone cells. 



Fig. 200. — Cassia Bark, Xno. 
Longitudinal section, showing bunches of bast 
fibers at the left, starch cells in the center, and 
stone cells at the right. 



PLATE XXI. 



SPICES. 




Fig. 20I. — Lcylon t mnanion liark, Xiio. FiG. 202. — Ceylon Cinnamon Bark, Xiio 

Transverse section, showing many bast fibers and Longitudinal section, showing bast fibers, stone 
starch cells. cells, and parenchyma. 




Fig. 203. — Powdered Cassia, Xiio. 
Showing stone cells, starch, and corky tissue. 



Fig. 204. — Powdered Cassia, Xiio. 
Showing bast fibers and starch. 



SPICES. 



PLATE XXII. 





I 



/ 



Fig. 20";. — Powdered Cassia, >( no. 
Showing large bast fiber and starch grains. 



Fig. 206. — .\dulterated Cassia, Xiio. 
A mass of foreign bark. 




Fig. 207. — Cayenne, X no. 
Transverse section through pericarp. 



Fig. 208. — Cayenne, ;< no. 
Transverse section through seed coat and part of 
endosperm. Collapsed parenchyma cells sepa 
rate endosperm from long epidermal cells. 



SPICES. 



PLATE XXIII. 




Fig. 20i). <\niiiiie, Xiio. 
Surface view of fruit eiiiderniis. 



Fig. 2IO. — Cayenne, Xiio. 
Surface view of two lavers of seed coat 





Fig. 211. — Powdered. Cayenne, Xiio. 
A large mass of fruit epidermis. 



Fig. 212. — Powdered Cayenne, Xiro. 
Showing chiefly two of the seed coat lavers. 



SPICES. 



PLATE XXIV. 










(S • 







<'■'": .' 



o. 




Fig. 213. — Adulterated Cayenne, X130. Fig. 214. — Adulterated Cayenne, X214. 

Corn and wheat starch and cocoanut shells appear The central mass is ground red wood, surrounded 
chiefly. .\ bit of cayenne is shown at the right. by corn starch grains. 



I 




Fig. 21 V — Clove, X6c. 



Fig. 216. — Clove, Xiio. 



Transverse section from the center outward to Transverse section near epidermis, showing large 
epidermis, showing parenchyma. oil caNaties. 



SPICES. 



PLATE XXV. 





Pig. 217. — Clove, ■ 28. 
Lontjiturlinal section through entire clove. 



Fig. 218.— Clove, X70. 
Central longitudinal section, showing duct bundles. 




Fig 21Q — Clove, ■■'no. 
Surface view of epidermis. 



Fig. 220. — PowiltTfil ( 1m\<-. <i3o. 
Dense, spongy tissue, with small oil drops. 



SPICES. 



PLATE XXVI. 




Fig. 221. — Clove Stem, X70. 
Transverse section through outer part of stem, 
showing bast fibers at the left, parenchyma in 
the center, and stone cells near the epidermis. 



Fig. 222. — Clove Stem, X25. 
Central longitudinal section through entire stem, 
showing bast fibers in the center, and stone cells 
at the right. 




Fig. 223. — Clove Stem, X70. 
Longitudinal section, showing the stone cells. 



Fig. 224. — Powdered Clove Stems, Xiid. 

Showing fragments of tissues, stone cells, and bast 

fibers. 



PLATE XXVII. 



SPICES. 



"-"^In 




^Bih^ 


^m-'x 




E^ 




43K^^ 


Pv 


I - .. 




P 


Fig. 225. — Powdered Clove Stems, X no. 


Showing 


bundle of bast fib 


ers. 



1 



.V 
















Fig. 226. — Adulterated Cloves, X 130. 
Showing chiefly stone cells of cocoanut shells. 




V M. 






Fig. 227. — Adulterated Cloves, X130. Fig 228. — Ginger, Xiio. 

With large admixture of cocoanut shells. Transverse section, showing starch cells with 



xxviir. 



M^ ^M^'. 



SPICES. 




<^ 



riG. 229. — Ginger, Xiio- Fig. jjo, (iiiiL,nr, ■ no. 

Transverse section, showing parenchyma, starch Longitudinal section, showing .spiral ducts and 
grains, and duct vessels. pigment cells. 



V^ I 






O 






^. 



fe 




Fig. 231. — Ginger Starch, X 220. 



Fig. 232. — .\dulterated Ginger, X 130. 
A mass of wheat bran tissue is most conspicuous. 



PLATE XXIX. 



SPICES. 













•'^,-> 

" ^'•5 









Fig. 233. — Adulterated Ginger, X130. Fig. 234. — Adulterated Ginger, X130. 

The central dark nass is a yellow fragment of Containing a large admi.xture of corn and wheat 

turmeric. starches 





Fig. :?35. — IVnimg Mace, ^iio. FiG. 236. — Bomba\ ur Wild Mace, Xiio. 

Transverse section through epidermis and oil cells. Transverse section through outer layers, showing 
showing also parenchyma with contents of yellow and red resinous lumps 

amylodextrin. 



PLATE XXX. 



SPICES. 




Fig. 237. — Nutmeg, Xiio. 
Transverse section through the exterior and in- 
terior teguments of the seed and part of the 
endosperm, showing starch cells. 



Fig. 23S. — Nutmcj, <25. 
Transverse section near exterior of seed. 



<5*-^-?a 




^^ > 






Fig 239. — Nutmeg, Xiio. 

Surface view of seed coat, showing also portions of 

underlying tissues. 




Fig. 240. — Powdered Nutmeg, Xiio. 



PLATE XXXI. 



SPICES. 




Fig. 241. — White Mustard, X 1 10 
Transverse section through mucilaginous epider- 
mis, sub-epidermal parenchyma layer (square 
cells), palisade cells, and broken parenchyma 
laver of the hull. 



Fig. 242. — White Mustard, Xiio. 

Transverse section through the tissue of the 

radicle. 





F:g. 243— White Mustard, Xiio 
Surface -iiew of t\vo layers of the hull or seed coat. 



Fig. 244. — White Mustard. Xiic. 
Surface section through palisade cells and under- 
lying layer of the seed coat 



SPICES. 



PLATE XXXII. 




Fig. 24v — Black Mustard, Xiio. 
Transverse section, showing fragments <'f the epi- 
dermis and dark colored palisade cells of the 
seed coat. 



Fig. 246. — Black Mustard, Xiio. 
Surface view of two of the seed coat lavers. 



. "e 



o 



¥J. ri^ 





^. 



'n 



r m^ 



Fig. 247. — Grounil Mu-tard, X 130. 
Ground without removal of the oil. 



Fig. 248. — Ground Mustard Hulls, Xiio 



SPICES. 



PLATE XXXIII. 




Fig. 249. — Dakuia .\iustard Flour, Xno. 
Dark spots show starch grains of foreign weed 
seed, stained with iodine 




• •■\, 



Fig. 250. — .-\.luiiLiai.L.i .\iu.,ianl Flour, X 130. 
Showing masses of wheat starch. 





Fig. 251. — Pepper, Xno. 
Transverse section through inner part of pericarp 
(including parenchyma and seed coat layers) and 
portion of perispemi, showing starch and oil 
cells. 



Fig. 252. — Pepper, Xno. 
Surface view of hypodermal layer. 



SPICES. 



PLATE XXXIV. 




Fig. 253. — Pepper, Xiio. 
Transverse section through outer part of pericarp, 
showing epidermis, underlying stone cell layers, 
parenchyma, and seed coat. 




Fig. 254. — Pepper, Xiio. 
Surface section through stone cell byer. 



kV-'\" 



> .V- 

\ V,- 









■^'.t.-.'i .- 



, ^'. o»- •>,.!< ..-ivft--"' '^ 






I'V -A ■<< 






■;*:^- 




1 

i 



Fig. 255. — Pepper Starch. X220. 
Starch granules separated. 



Fig. 256. — Pepper Starch, Xno 
Starch grains in masses. 



SPICES. 



PLATE XXXV. 




Fig. 257. — Ground Pepper Shells, X no- 
Mainly sho\ving stone cells. 









^■■,*^' 




p# :tf 



Fig. 25S. — Adulterated Pepper, X 130. 
Showing wheat and buckwheat starches. 






r.* a(-. 









■^^g^ .-O^i 



.<«o « 



00 






A,S^ 






Fig 259. — Adultri.iu .1 Pepper, X130. 
Showing wheat, corn, and rice starches. 






a. -,- > 






^^. 






Fig. 260. — Adii!trr,[ii <l Pepper, X130. 
The large, lower mass shows buckwheat starch, 
while the finer-grained mass near the top is of 
pepper. 



PLATE XXXVI. 



SPICES. SPICE ADULTERANTS. 




Fig. 261. — Adultei.iud TLppL-r, Xiio. Fig. 262. — .Adulterated Pepper, X130. 

The central mass shows the sclerenchyma cells of Cayenne and wheat starch are the adulterants, 
olive stones. 



-..v«J;^ 











411 






f 


Fig. 263.- 


—Powdered Olive Stones, Xiio. 


Fig. 264 




Fig. 264. — Powdered Cocoanut Shells, Xiio 



SPICE ADULTERANTS. 



PLATE XXXVII. 



:i,A^ »' 



■.*• . , =*. ♦ 











^^^X. 



.*• -'1. ■ . • ■■*> V -^.. »i, -' « - 
• < *. 

Fig. 265. — Powdered Elm Bark, Xno. 



X 



Fig. 260.- I'iue .s.iu'dust, Xiio. 
Finely ground. 




Fig. 267. — Pine Wood, Xiio. 
Transverse section. 



Fig. 20S. — Pine \\ uud, X 1 10 
Radial and tangential sections. 



PLATE XXXVIII. 



EDIBLE FATS. 




Fig. 269. — Pure Butter, X25. 
With polarized light and selenite plate. 




Fig. 270. — Process or Renovated Butter, X25. 
With polarized light and selenite plate 



Fir., 271. — Oleomargarine, X25. 
With poiurijed light and selenite plate. 



PLATE XXXIX. 



EDIBLE FATS. 




Fio. 272. — Lard Stearin, Xiio. 
I.caf lard, crystallized from ether. 



Fig. 273. — Lard .Stearin, X220. 
Leaf lard, cr>-stallized from ether. 




Fig. 274. — Lard Stearin, X220. 
"Back" lard, crystallized from ether. 



Fig. 275. — Lard Stearin, X480. 
"Back" lard, cr\'stallized from ether. 



PLATE XL. 



EDIBLE FATS. 



.^^^-^X^^^t. 




Fig. 276. — Beef Stearin, X35. 
Crv'stallized from ether. 





't. 



Fig. 277. — Beef Stearin, Xiio. 
Crystallized from ether. 



fiG. 27S. LllI Stearin, X22o. 
Crystallized from ether. 



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